However, after a quick search on the internet, it seems there are many low cost CAT III rated meters available. I would like to know if any of these can handle CAT II.Anything that's CAT III is also CAT II.
Why am I only interested in testing them at CAT II? Well that's about the only thing I would ever dare use any hand held meter for.The difference between CAT II and CAT III is very subtle in practice.
Well that's about the only thing I would ever dare use any hand held meter for.Me? I wouldn't use anything less than CAT III for regular mains work and I'd want a meter which I KNOW is CAT III, which in practice means Fluke. The numbers printed on the front of certain other brands of meter have been shown to be lies many times in these forums.
Me? I wouldn't use anything less than CAT III for regular mains work and I'd want a meter which I KNOW is CAT III, which in practice means Fluke. The numbers printed on the front of other brands of meter have been shown to be lies many times in these forums.
A Fluke 101 can be had for under $45, is easy to find, and comes with proper covered probes for mains AC work.
For that price I don't see any point in using anything else.
Interesting. Looking foward to se some test results.
Do you have any meters in mind for destruction?
A Fluke 101 can be had for under $45, is easy to find, and comes with proper covered probes for mains AC work.
A Fluke 101 can be had for under $45, is easy to find, and comes with proper covered probes for mains AC work.I'll check. I have another Fluke in mind and am not apposed to testing more of them if they meet the criteria.
LIMITED WARRANTY AND LIMITATION OF LIABILITY
This Fluke product will be free from defects in material and workmanship for one year from the date of purchase. This
warranty does not cover fuses, disposable batteries, or damage from accident, neglect, misuse, alteration, contamination, or
abnormal conditions of operation or handling.
Great video.
I think this one from amprobe could be a fun test:
Amprobe AM-510 for 44 $ on ebay
This too:
Amprobe AM-34 for 45 $
Or this one if it would drop just a tinsy bit in price and be available outside europe. From your video you don't sound european.
PeakTech 2015. It has really good features i think. Could not find a teardown of it, but some of the higher end models seems well build.
I would like to see the Elix AL72D tested. It is a cheap multimeter sold by ALDI and some other discount supermarkets. They claim CATII and maybe it will survive the 750VAC or 1KVDC.
This model is also sold as the Range RE93A and I think under many other 'brands'.
The retailprice of this multimeter is somewhere between €10 and €15.
joeqsmith:
I'm interested in your surge generator. Perhaps a schematic would be helpful.
How are you triggering the discharge of the capacitor bank? Or are you just charging it until it arcs over in the DUT?
I am also interested in this as I am working on surge testing at the moment, it would be interesting to compare home made vs professional unit. Can you post your schematic JoeQ?
The Cen-Tech was not on schedule, right? It looks like a nice meter on paper. I'm gonna see how it performs on the tests.
I'm impressed by your commitment to test so many units financing this by yourself. You truly are a curious person.
My only suggestion is that you come up with a definitive test so we can compare the meters directly, before you do more damage.
It sounds like the 28 II may be more robust than the 87V.
If you would like me to test your favorite meter, my criteria now is that they must be a hand held meter, marked CAT III (600V) or higher, cost under $50 US and be fused.I don't have any of these meters and they are not my favorites, but if you are still interested in the under $50, CAT III and fused criteria, here are some more using pricing from Amazon.com.
Dave hates (feline) cats.I vote we start sending him cat-related items in the mail.
Dave hates (feline) cats.I vote we start sending him cat-related items in the mail.
Muttley's close, he could send Dave a cat, bugger the litter. :-DDI'm sure Dave would come around if he actually had a kitten at home.
If you would like me to test your favorite meter, my criteria now is that they must be a hand held meter, marked CAT III (600V) or higher, cost under $50 US and be fused.I don't have any of these meters and they are not my favorites, but if you are still interested in the under $50, CAT III and fused criteria, here are some more using pricing from Amazon.com.
Greenlee DM-45
Uni-t UT61E - very popular recommendation by some eevblog people
Tekpower TP2844R
I can probably find more, but it will make a dent in your wallet if I continue. You have already ordered 8 meters and probably spent over $300 already.
BTW, can you provide some internal pictures of the DM-301? I would be interesting to see the inside construction of this. Your video showing the pcb was too fast and I can't see anything too clearly.
Protek made a DM301 that looks like the one in your video.
http://www.hcqelectronic.com/en/a/Digital_Multimeter/20140919/71.html (http://www.hcqelectronic.com/en/a/Digital_Multimeter/20140919/71.html)
Dang where were you when I was looking for meters?!The subject header with kitty, kitty, kitty did not attract my attention and I didn't notice the CAT III handheld surge tests due to the way my screen wraps.
Picture showing PTC, zener and cut away areas.I think the green component that I circled in blue looks to be a varistor (MOV). If I'm correct, it is this component that is helping the DM-301 survive your tests.
Dang where were you when I was looking for meters?!The subject header with kitty, kitty, kitty did not attract my attention and I didn't notice the CAT III handheld surge tests due to the way my screen wraps.
Anyway, if you want more suggestions, I will look for more meters that fit your criteria. If not, no worries.
That looks like an 830. I'm not surprised it did so well, there's not much to go wrong in them and if something arcs over on the surge that'll just "relieve" the stress instead of popping the IC.
I think the green component that I circled in blue looks to be a varistor (MOV). If I'm correct, it is this component that is helping the DM-301 survive your tests.
Picture showing PTC, zener and cut away areas.I think the green component that I circled in blue looks to be a varistor (MOV). If I'm correct, it is this component that is helping the DM-301 survive your tests.
The Fluke might not have been one of the five tested.
https://www.youtube.com/watch?v=dLfhQn9LwyA&feature=youtu.be (https://www.youtube.com/watch?v=dLfhQn9LwyA&feature=youtu.be)
Thanks for putting these together. I think this thread is the first were anyone has shown DMM's subject to approximations of IEC surge waveforms.
A question is at just that amount of energy, do they die gracefully or survive? Survive would be a plus, money wise.
Are any of the test meters safety rated by external NRTL labs? The B&K that failed?
In Dave's early videos, the energies are far above their CAT ratings, but its most useful because it shows how the meters respond in a severe failure.
I am hitting them with far less energy than the IEC standards call for. When I tested my old Fluke, that was the most violent failure so far. But we are just getting started..... :-DD
Again the real energy would come from the mains and I am not using anything like this in my testing. So even if a meter were to pass all of my tests, it should be obvious that this does not
mean it would pass the real IEC standards.
Correct me if I'm wrong, but meters are expendable and people are not. So believe the IEC tests are intended to ensure that any damage stays inside the meter and does not cause injury to a person holding it. For a meter itself to survive unharmed seems like a very strong requirement.
Halvmand's AMPROBE AM-510
https://www.youtube.com/watch?v=Hcv6ADmf4Q8&feature=youtu.be (https://www.youtube.com/watch?v=Hcv6ADmf4Q8&feature=youtu.be)
This meter was later fully tested. Gets the big :-+
I have been a long time lurker, and reader, of these forums. I have not found the need to post until this thread.
I actually have done some IEC 61010 surge testing on meters, and I think you have done a great job building your own tester. I also like seeing how many of these low cost meters survive these surges. However, to meet the CAT ratings in 61010, they do not HAVE TO pass these surges.
My understanding of IEC 61010 is that the meter must not become a hazard when they take this surge. That means not flames or explosions when you hit the meter with the surge. Or, no broken cases or flying parts. But, the meter does not have to function after the surge to get the rating. So, a meter that arcs over a trace or dial pad, but does not blow apart, would be considered a pass.
It is nice to know that some of these low end meters still function after your surges. But, they are not required to.
All text of IEC 61010-1:2001 is included. National Deviations are shown by strikeout through text
deleted and underline under text added. Tables, or portions of tables, that are to be deleted are
shown as shaded; figures to be deleted are marked with the overlay "X." There are eleven
annexes in this standard. Annexes G, H, DVA, DVB, and DVC are informative and are not
considered part of this Standard. The remaining Annexes are normative and are considered part
of this standard.
How can we find a copy of the IEC 61010-1 3rd edition?With Google. (http://www.google.com/search?q=IEC+61010-1%3A2010+pdf)
The Klein Tools MM500
In 61010-1 3rd Edition, the over voltage and surge tests have been removed. They are now covered in 61010-2-033 for DMM's and 61010-2-032 for clamp meters.
...
Of course, the better designed units can survive that over voltage, and still function.
The Klein Tools MM500
In your video, you said you believed that Klein unit could survive higher than a 10 foot drop. A quick google search returned this.
Dave also took that meter on his mud run, and it survived that.
In 61010-1 3rd Edition, the over voltage and surge tests have been removed. They are now covered in 61010-2-033 for DMM's and 61010-2-032 for clamp meters.
...
Of course, the better designed units can survive that over voltage, and still function.
61010-2-033 is what I quoted.
The goal is the same no matter. One meter will be more robust than the others.The Klein Tools MM500
In your video, you said you believed that Klein unit could survive higher than a 10 foot drop. A quick google search returned this.
Dave also took that meter on his mud run, and it survived that.
I like the video!! I had never heard of the brand until now.
If I needed to have a very limited meter on a mud run to do some 1K resistor measurements, this would be it. :-+ It's so light weight and solid, after these tests I may try and see what it takes to damage it. Maybe drop it out of a plane or shoot it out of a cannon... :-DD
Klein is an american company that tends to focus on tools for electricians and telecommunications. I wonder who is manufacturing this meter for them. I am sure some others know of a few Korean multimeter companies. I can't think of any off the top of my head.Fine Instruments makes some of Klein's multimeters. See
It's so light weight and solid, after these tests I may try and see what it takes to damage it. Maybe drop it out of a plane or shoot it out of a cannon... :-DDJoe. Your disrepect of perfectly good test equipment worries me.
It's so light weight and solid, after these tests I may try and see what it takes to damage it. Maybe drop it out of a plane or shoot it out of a cannon... :-DDJoe. Your disrepect of perfectly good test equipment worries me.
Some might say you are a sick puppy. ;)
Great thread, watched it all the way. :popcorn:
So, which 2 of the 6 that passed the 2kV testing died? Will you be hitting the remaining 4 with 3.5kV today?
Well, I'm not really hoping for a certain winner, so I don't know what you think I'm expecting. But, based solely on the strength of the brands, I would guess the Extech and Uni-T would be the 2 that didn't make your last test. I expect the Fluke to go the distance.
I am looking forward to see the rest of your testing. I do surge testing on telecom equipment, but don't test meters for my job. I love blowing stuff up with that machine. The lab I work in does have a surge generator that can do 12kV through 2 ohms for IEC testing. My telecom testing does not require me to go that high, so I don't use that machine. But, I'm not going to spend money buying meters just to see how they hold up on that machine. I guess I'm just not as curious as you. But, I am curious enough to follow this thread, and see which brand holds up the best.
Just a warning, the results may not be what you're expecting.
Joe, continued good job :-+, I watch videos with as much anticipation as Game of Thrones ;D. I am away for awhile so can't post for sometime. Keep up the good work. :popcorn:
101.4 Functional integrity
After the voltage of 4.4.2.101 has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
In your video, you said you believed that Klein unit could survive higher than a 10 foot drop. A quick google search returned this.Those $4 Chinese meters can survive that...
Really, you specifically should run these tests! If you can do the 8/20 2 ohm, you are all set. Think your work would let you rent the lab for 4 days free of charge? :-DD
At the bottom of the page when posting there is a plus sign for attachments, click this and follow your nose. ;)
I have a picture of the beast the day it arrived, but I don't know how to post it on here.
At the bottom of the page when posting there is a plus sign for attachments, click this and follow your nose. ;)
I have a picture of the beast the day it arrived, but I don't know how to post it on here.
Note the restrictions of type and size of files.
I suggest you compress the pics, usually 100K will give plenty of detail.
If you Quote somebodies post, you will see the various formats used to display pics.
Some host pics, others use EEVblog and upload.
Really, you specifically should run these tests! If you can do the 8/20 2 ohm, you are all set. Think your work would let you rent the lab for 4 days free of charge? :-DD
There wouldn't be a need to "rent it". I can have access to it whenever I want. My point was that I was not going to spend my money ordering out meters to blow up for the fun of it. I would have fun doing it, but I have other uses for my money.
However, I really appreciate that dedicated people like you have no issue spending money for that kind of fun.
I've attached a picture of the surge generator. It is 27 inches high, and 24 deep, and about 17 wide. The thing weighs over 100 pounds, and can deliver the full 6000 Amps at 12 kV. If I remember right, it set the lab back about $34,000.
Imagine the fun!!You're >:D >:D >:D
Quote101.4 Functional integrity
After the voltage of 4.4.2.101 has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
If this is relevant, then any meter you have failed before this video that also has a CATII rating or higher can't be sold in the EU legally. The ones that failed this video with a CATIII rating also cannot. It is my understanding, from watching a video by Martin Lorton at the Fluke facilities, that the US has no restrictions on the legal sale of multimeters, not yet.
There is another part that specifies that any meter should not fail in a way that could harm the user. I wonder how that is actually tested without putting a person in harm's way?
REASONABLY FORESEEABLE MISUSEThese people have no idea what I consider reasonable misuse!
61010-2-033:2012
....
101 Measuring circuits
....
101.4 Functional integrity
After the voltage of 4.4.2.101 has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
....
NOTE The METER is not required to maintain its normal accuracy. A maximum deviation of 10 % is acceptable.
....
Conformity is checked by inspection while applying the maximum RATED voltage of each
voltage measurement range capable of MAINS voltage measurements.
.....
4.4.2.101 Input voltages
For measuring circuit TERMINALS RATED for MAINS CIRCUITS voltage measurements:
.....
14.101 Circuits or components used as TRANSIENT OVERVOLTAGE limiting devices in
measuring circuits used to measure MAINS
The test voltage is applied between each pair of TERMINALS, used to measure MAINS, where
voltage-limiting devices are present.
NOTE This test can be extremely hazardous. Explosion shields and other provisions can be used to protect
personnel performing the test.
I wonder how that is actually tested without putting a person in harm's way?
That was pretty funny! Did you take the battery apart and find some small button batteries inside?It rattled enough...
Your recommended Fluke 101 is holding up just fine so far.I'd be surprised if it didn't. We know Fluke take the component layouts, track gaps, etc., very seriously. I suspect they left out the current measurement in the 101 because it's impossible to do a safe layout for a low-impedance path through a meter that small.
My only real complaints with this meter is how slow the continuity test is and the lack of a back light for the LCD.It's not a great meter for electronics work but it's a pretty good meter for an electrician, especially with the safety probes (which I don't think any of your other meters have).
It's not a great meter for electronics work but it's a pretty good meter for an electrician, especially with the safety probes (which I don't think any of your other meters have).
It's not a great meter for electronics work but it's a pretty good meter for an electrician, especially with the safety probes (which I don't think any of your other meters have).
Could you start by post a few pictures of what you are calling safety probes? I'll post a few of what was included with the meters. I suspect you have seen a different set of leads supplied with the 101 than what I received.
I am very interested to see how the UT139C behaves with your tests. I have been recommending it as a worthy meter for almost anything a hobbyist would need a meter for. It sure looks like it has proper input protection, so hopefully we will see!
:-DD I was not able to find the correct manual for it. Is the jumper on the left the 2 ohm and the right 12? So you add a jumper for the source?
I do not see where the power feeds into it from the manual or how if connects to the different circuits. They have a simple schematic and call out the values used. They do not show the AC at all. Is it basically just for the telcom industry?
Ones I am used to can impose the wave on the AC. L-L L-N L-G .... It then synchronizes with the AC wave. I think we can handle a 30A 4-wire circuit with ours and are limited to 300V for the mains. To test the meters you would need to have the signal ride on the AC. Imagine the fun!!
If it really is just the waveform, it still has the potential to do far more damage than my homemade generator.
You killed the Klein.
And here you go. Pictures of the Fluke 101, BK 2703C and the MASTECH probes. I fail to see why the Fluke 101 probes would be considered a safety probe.OK, they have them as well...
And here you go. Pictures of the Fluke 101, BK 2703C and the MASTECH probes. I fail to see why the Fluke 101 probes would be considered a safety probe.OK, they have them as well...
Point is: Many cheap meters don't have decent probes.
I think we can handle a 30A 4-wire circuit with ours and are limited to 300V for the mains. To test the meters you would need to have the signal ride on the AC. Imagine the fun!!
I think we can handle a 30A 4-wire circuit with ours and are limited to 300V for the mains. To test the meters you would need to have the signal ride on the AC. Imagine the fun!!
So, based on this comment, it seems your work has a more powerful machine than what you built up. Any chance you can put the 3 survivors on that?
Now we are talking! :-+ 2 phase 16A model?
You get it all running, I am curious how fast it charges in 8KV. Ours takes about 20 seconds for 5KV.
I am very interested to see how the UT139C behaves with your tests. I have been recommending it as a worthy meter for almost anything a hobbyist would need a meter for. It sure looks like it has proper input protection, so hopefully we will see!
Interesting that the UT90A only failed on the diode test. I figured that it would have fried the resistance measurenment as well.
Buy/Sell/Wanted. DMMs like new little used. :-DD
Time to start thinking about what to do with so many non-functional meters.......
I am sorry to say that I have been unable to declare a winner.
Interesting that the UT90A only failed on the diode test. I figured that it would have fried the resistance measurenment as well.
As far as I understand the standards, every function is to be tested with every terminal.
Now, I realize Joe is testing these to see which meter can take his abuse the best. But, I don't think any of us should expect a meter to see an 4kV spike (or survive one) when doing a diode test.
As far as I understand the standards, every function is to be tested with every terminal.
That's not the way I read the standards.
As far as I understand the standards, every function is to be tested with every terminal.
That's not the way I read the standards.
Unfortunately I do not have the full standards, and that is why I qualified the statement. Like I said before, the IEC is doing a big disservice by making the standards available for payment only. These are public safety standards and as such should be made publicly free so the average Joe can see them.
If you're dealing with inductive loads you may also encounter spikes. Even a little DC relay can generate 300v spikes. https://www.youtube.com/watch?v=c6I7Ycbv8B8 (https://www.youtube.com/watch?v=c6I7Ycbv8B8)Now, I realize Joe is testing these to see which meter can take his abuse the best. But, I don't think any of us should expect a meter to see an 4kV spike (or survive one) when doing a diode test.
It's worse than that. I think the chances of there being a 4 kV spike on the mains at the exact instant I am measuring the voltage is in the millions to one region. I would have more chance of winning the lottery than experiencing that event. Consider that in the half century of my lifetime there have been multitudes of devices plugged in to the mains 24 h a day in all the homes I have lived in, and none of them have experienced damage from such a surge. That's tens of thousands of hours of constant connection to the mains without such an event. Compare that to the maybe five minutes total I have spent probing the mains (assuming each measurement takes only a few seconds to make).
I think that for the industrial electrician, a professional tool is required that meets such standards.
For normal consumers in a home environment, such testing regimes are totally out of proportion to the risk. Mandating such testing for consumer retail devices is simply forcing prices up unnecessarily.
(On the other hand, if a device is marked with a certain rating, then it certainly ought to be required to be compliant with those standards.)
As far as I understand the standards, every function is to be tested with every terminal.
That's not the way I read the standards.
Unfortunately I do not have the full standards, and that is why I qualified the statement. Like I said before, the IEC is doing a big disservice by making the standards available for payment only. These are public safety standards and as such should be made publicly free so the average Joe can see them.
If you're dealing with inductive loads you may also encounter spikes. Even a little DC relay can generate 300v spikes.
Buy/Sell/Wanted. DMMs like new little used. :-DD
Time to start thinking about what to do with so many non-functional meters.......
I am sorry to say that I have been unable to declare a winner.
Can you ramp it up any higher? Keep going until one of them breaks.
Now, I realize Joe is testing these to see which meter can take his abuse the best. But, I don't think any of us should expect a meter to see an 4kV spike (or survive one) when doing a diode test.
Have you tested the Fluke 101 yet?
Great! One question. What happened to the UT139C. Your last video ended before the end of the testing. Did I miss something?
It's not so much that it died, it is how it died. The video will be well worth watching.Shrapnel?
It's not so much that it died, it is how it died. The video will be well worth watching.Shrapnel?
Thanks! I was surprised that the UT139C died. It looked very promising and I have one here. I was impressed by it but maybe not now.
As far as I understand the standards, every function is to be tested with every terminal.
Fluke meters at the low end are very spartan, they don't skimp on protection but the features take a back seat.You say that like it's a bad thing.
Heh, I am just thinking of people who are just getting into electronics and what to recommend to them, if I was on a tight budget for my first multimeter I would be hard pressed between the Amprobe and the F-101. I would most likely pick the Amprobe. For mid range meters and upper tier, definitely Fluke 87.Fluke meters at the low end are very spartan, they don't skimp on protection but the features take a back seat.You say that like it's a bad thing.
Heh, I am just thinking of people who are just getting into electronics and what to recommend to them, if I was on a tight budget for my first multimeter I would be hard pressed between the Amprobe and the F-101.The Fluke lacks current measurement. Definitely not good for electronics work (it's aimed more at electricians).
Amazon lists AM-510 at $37.88. Pretty impressive.Yep. Seems like a nice meter for that price.
Amprobe seems to use three different manufacturers for their products, at least three. The AM-5x0 series seem to be made by Uni-T, at least that what has been speculated by some here on the forums. The AM-270, AM-140 and 160 are definitely made by Brymen. The others in the AM-2x0 series are not clear. The XR series were originally sold by other brands and bought out so I am not sure who actually makes those. The HD series is an unknown to me but they sure seem to be made tough.
Not sure about the XR series, maybe these are wavetek too?XR came from acquistion of Meterman.
It is not my intent to diminish the work and findings of joeqsmith with what I am about to say. His tests show one thing and one thing only, ie the ability of a meter to survive his pulse tests. This is something to consider when buying a meter but it is not the only criteria that a newbie should used in selecting a meter.
Safety is important, but none of these videos demonstrated an unsafe condition that I could see.
Thanks for the video. The failure of the UT139C seems to have been either a faulty PTC, bad spacing on the tracks that caused an arc over and then the failure of the PTC which then overloaded the MOVs too many times and then every time after the MOVs were a dead short and caused the big flashes.
If you are willing, I think it would make good videos investigating the failure mode of at least some of the meters and see if they could be repaired by just replacing a part or two.
I was amazed that you killed the Klein, I liked its small size/lack of features.
Hi Joe,
Since you are skilled enough to build your own generator, and have demonstrated coupling voltage with the surges, I could use your advice.
I want to couple AC voltage with the surge generator I pictured in this thread. I've researched what inductor should be used to couple this, and 1.5 mH seems the most common recommendation. But, I also want a inductor that can handle a considerable amount of current. So, I found a few 10A inductors, but not a 1.5 mH. In the 10A rating, they have a 1 mH, and a 2.5 mH. Could you tell me which size inductor would be the best to use with the 1.2/50 pulse width?
It is not my intent to diminish the work and findings of joeqsmith with what I am about to say. His tests show one thing and one thing only, ie the ability of a meter to survive his pulse tests. This is something to consider when buying a meter but it is not the only criteria that a newbie should used in selecting a meter.
No problem.
This may be all you took away from this experiment but there was a lot to learn. I understand, you sell products like hand held meters. I'm not suggesting you would ever add your own bias to make more sales. You just need to make sure that you understand what is going on before you use this information as part of your sales pitch.Safety is important, but none of these videos demonstrated an unsafe condition that I could see.
That was never a goal. Comments like this are why I don't think you really understand what can happen. I covered this subject upfront. If you don't feel that there are any concerns when an arc is combined with a high energy source, so be it. Personally, I would not trivialize it to my customers.
Thanks for the video. The failure of the UT139C seems to have been either a faulty PTC, bad spacing on the tracks that caused an arc over and then the failure of the PTC which then overloaded the MOVs too many times and then every time after the MOVs were a dead short and caused the big flashes.
If you are willing, I think it would make good videos investigating the failure mode of at least some of the meters and see if they could be repaired by just replacing a part or two.
There is no reason to spend a whole lot of time attempting to repair low cost devices like these. Just buy a new one. The goal was to find a meter that would survive, then you wouldn't need to be so concerned about replacing it. I showed where most meters were damaged in the video.
That said, I did waste some time repairing the UNI-T UT90A. The control IC was still good. Three traces had vaporized. One diode was shorted, 2 resistors were open. I aligned it and it seems fine. Nothing I would give away because of the damage to the switch area.
Sounds like you are most interested in the UT139C. Q8, Q9, Q2, Q3, R42 and the main control IC are all damaged. While the heat cracked the insulation around the one PTC, both of them are still fine.
Most of the damaged meters were ran again at even higher voltages, causing even further damage to them.
Sorry, I can't be of help other than suggest your life insurance is paid up. I just don't know enough about it. It's not just the current and inductance, that's a lot of voltage.
Sorry, I can't be of help other than suggest your life insurance is paid up. I just don't know enough about it. It's not just the current and inductance, that's a lot of voltage.
I find that statement kind of funny, since it is coming from a guy who was doing his testing with the open meter a few feet away, and even changing switch positions while timing out the surges. At least I built a blast chamber made with half inch Lexan for my testing.
But, I get you not wanting to give advice if something went wrong on my end. I would have not coupled through 400V. I would have started with less than 100V, and put some 10A HRC fuses in line to limit any danger. The spec says that blowing the circuit breaker would be a failure to this test, so opening those fuses would be an indication of failure. That would help limit any danger.
The thing you did not mention is that I posted once how I had stopped testing because I was burned out and started to make some mistakes.That certainly must have taken a lot of time to do. I certainly enjoyed the experiment and I appreciate you sharing it with us.
I can alssay that I enjoyed them too. I think many people were grateful for your time and expense that put forward for the benefit of all. :-+
Great job Joe!!
Now that I know the top meter, I wouldn't mind getting the Fluke 101, and see how much higher it can go. Now, I wouldn't have to buy 10 meters like you did, I could get just the one. It would be interesting to see how far beyond 6kV it could go, since I could take it all the way to 12kV.
Too bad none of the companies you contacted got back to you. Since Fluke was the winner, it would have been nice for them to send you something else. Maybe they still will. But, it sucks that no companies even acknowledged you emails.
You should consider selling those boxes. Like you said, they go for 10's of thousands. You could make a killing selling yours to people who can't afford the big ones.
Quite the carnage ;D
Good job on the repaired ones.
Had I not fried them with the neon sign transformer, shot at them with arrows, used Dave's Dremel technique to attempt to repair them and rezapping them over and over again with my generator, more could have been saved.
The Fluke 101 and transient generator will remain untouched until the next test.
Yeah, it looked like the Klein just needed a new PTC, but the case was so trashed, what's the point?
What's the next test? You taking the generator up to 8kV?? Or, are some of these companies giving you higher end meters to test??
Thanks for all of the kind words.
A few things I would like to add. There has been some debate about if a meter would need to be functional after surge testing or not. I have heard from some manufactures who say they do not. I have no idea and would have to ask. However, I did find this series of videos on-line that Fluke put out.
The conclusion (yet again) is that Fluke hold themselves to a higher standard than what's required to get the official rubber stamp of approval.Quote from: fluke“Fluke goes a step further in designing and building our test tools for your safety. With stout input protection and high energy fuses, our meters are built to survive.”Now I guess there is still room for interpretation but it seems pretty clear to me what Fluke requires.
The conclusion (yet again) is that Fluke hold themselves to a higher standard than what's required to get the official rubber stamp of approval.Quote from: fluke“Fluke goes a step further in designing and building our test tools for your safety. With stout input protection and high energy fuses, our meters are built to survive.”Now I guess there is still room for interpretation but it seems pretty clear to me what Fluke requires.
Now.... if only their fuses weren't so expensive to replace and they could figure out how to make meters that start up in DC mode instead of AC. Then they'd be perfect.
A 1000 volt category three tester is require to survive a minimum of ten transients of both positive and negative 8000 volts without being damaged or creating a hazard.Then they go on to say "..Fluke goes a step further ..." Followed by a demonstration of the meter running up to 17KV before failure. So yes, I agree with your comment that Fluke does hold themselves to a higher standard as 17KV is much higher than the 8KV required for the CAT III 1000V meter being shown. Their words, not mine.
I've sold a number of 15B's, got an extra one for personal use and been rapped with it.Somebody rapped you with a Fluke? Knuckles or head? Either way it sounds nasty.
So yes, I agree with your comment that Fluke does hold themselves to a higher standard as 17KV is much higher than the 8KV required for the CAT III 1000V meter being shown.17KV is much higher than the 12KV required for CAT IV 100V rating.
So yes, I agree with your comment that Fluke does hold themselves to a higher standard as 17KV is much higher than the 8KV required for the CAT III 1000V meter being shown.17KV is much higher than the 12KV required for CAT IV 100V rating.
(And I'm sure most other manufacturers would have gone with the higher rating...)
The 287/9 are not CAT III rated.???
The 287/9 are not CAT III rated.???
A picture from the manual shows it 1000V CAT III rated. Or am I misinterpreting your statement?
http://www.amazon.com/Fluke-287-Electronics-Multimeter-TrendCapture/dp/B0015PMU8E
Specifications include European Conformity (CE) marking, UL, CSA, IEC safety standard 61010 and is certified for Category I installations up to 1000V and Category II installations up to 300V
But 28/II is a tank and it uses AAA batteries.The 27 II and 28 II both use three AA cells for approximately 800 hours. Eneloops work fine in them.
Maybe the 87IV was not popular.The battery life of the 87IV/89IV/187/189 is only 72 hours with 4 AA. I have a 187 and use Eneloops with it. So battery life isn't an issue as I always have Eneloops charged and ready to go.
Duh I just replaced them last week and you'd think I'd remember. Thanks for the correction(s).But 28/II is a tank and it uses AAA batteries.The 27 II and 28 II both use three AA cells for approximately 800 hours. Eneloops work fine in them.
Yes. :-[17KV is much higher than the 12KV required for CAT IV 100V rating.I assume you meant CAT IV 1000.
(I'm sure most other manufacturers would have gone with the higher rating...)
Note that the meter in the video is not CAT IV 1000.I know, but if they test them to 17000V then they could easily label it "CAT IV 1000V". For some reason they don't (maybe that would need better probes or something and push the price up, or maybe they just like to leave a safety margin on their ratings).
I know, but if they test them to 17000V then they could easily label it "CAT IV 1000V". For some reason they don't (maybe that would need better probes or something and push the price up, or maybe they just like to leave a safety margin on their ratings).
Cranked up the generator to 6.5KV 40uS into an open using the 2 ohm source. The waveform is attached. This is about 700 volts over what I had the two final meters at. I then repeated the test using the Fluke 101 all modes, both +/-. Once again, the Fluke remains fully functional. The more I beat it up, the more impressed I am.
This really is the limit of the generator. There is no room inside to add more storage and pushing it harder is just going to damage it.
Cranked up the generator to 6.5KV 40uS into an open using the 2 ohm source. The waveform is attached. This is about 700 volts over what I had the two final meters at. I then repeated the test using the Fluke 101 all modes, both +/-. Once again, the Fluke remains fully functional. The more I beat it up, the more impressed I am.
This really is the limit of the generator. There is no room inside to add more storage and pushing it harder is just going to damage it.
What voltage are the caps in your bank rated for? Couldn't you charge them with the output of that neon sign transformer that you used for your Jacob's ladder? That way, you would need to get your internal DC converter to put out a higher voltage. You would just need to limit what level you charged the caps to.
The caps (storage) are the limiting factor. Are you going to run the 101 on your 12KV setup?
The 101 arrived, and I tested it after I got off work.
The unit survived the full 12kV!! I hit it 3 times, each polarity, on all switch settings. Everything was fully functional, as I tested every single position.
I actually started at a lower level, an not right a 12kV. I hit it 3 pulses of each polarity at 6, 8, 10, and then 12kV. After the Fluke passed all of that, I blew up another $5 Harbor Freight meter, just to prove to myself everything was working.
I recorded the testing, but there is no point in posting it, as NOTHING happened.
I also took a short video of the inside of the surge generator, so everyone can see it's construction. I'll post a link as soon as it finishes uploading.
:-DD :-DD I was afraid of that! Fungus called this one!
So we are all clear, I have a few questions.
Are you using the 1.2/50 8/20 surge, 2 ohm source?
Was there any sort of bias on the meter when you hit it with the transients?
Did you verify the waveform?
And of course, what's it going to take to damage one of these!!?? It's a cheap $50 meter, how hard can it be??
:-DD :-DD I was afraid of that! Fungus called this one!
So we are all clear, I have a few questions.
Are you using the 1.2/50 8/20 surge, 2 ohm source?
Was there any sort of bias on the meter when you hit it with the transients?
Did you verify the waveform?
And of course, what's it going to take to damage one of these!!?? It's a cheap $50 meter, how hard can it be??
Yes, it was a 1.2/50 8/20 surge. That is the only wave this machine does, as it was designed exclusivley to test 61010-1.
No bias. I am looking into a CDN, but do not have one yet. I doubt a bias would have done anything, as there was no arcing at all during the surge testing. Yes, it would add continuous energy after an arc started, but I don't believe there was any arcing.
I did not verify the waveform. I do not have a high voltage probe for my scope. But, this machine is calibrated, and the waveforms verified during calibration.
It looks like Fluke may be true to it's claim that these meters will survive upwards of 17kV. I'm going to open the Fluke, and see what MOV's they are using, and what type of capacity they have. Maybe they can clamp these levels. It looks like someone my need to build a 20kV generator, or increase the length of the pulse to kill these with a surge.
What sort of rep rate were you hitting it at?
The video of me hitting the 12kV was a total of 12 minutes long, with all the pulses as described above. If I have time this weekend, I will move it off the GoPro camera, speed it up so it's not 12 minutes, and post it. It just seems like a waste, because it is just me changing dial positions, and hitting the discharge button. No good blast to see, or hear.
Good luck with your 10kV testing (looks closer to 12kV on that waveform). Based on my testing, you will be quite bored.
Guessing that was a custom unit for Fluke.
Joe,
I looked back at that document you posted on page 2 of this thread. It was from Advanced Energy on building and testing surge generators. That document shows the pulse length markers from the 50% amplitude on the rise, to 50% on the fall. It matches the waveform from my generator dead on.
If you look at your latest waveform compared to that document, your decay pulse is more like 20 uSec, instead of the 50 you want.
They use FWHH to measure peak shape. I am using the 100/0 which I thought was very clear from all of the scope shots. But then I have made statements about how it compares with 61010 so I can see how I clouded things up.
Still it's not a big deal. I'm starting to sound a bit like a broken record but again, I was not too concerned about what I hit the meters with, as long as they were all tested the same. Again, I am not trying to certify the meters for CAT III.
Guessing that was a custom unit for Fluke.
Found what looks to be that model on-line. The specs say it can go to 33 kV, and deliver 30 kA. I don't even want to know what a machine like that costs.
I think the 30A 8KV system we looked at last was around $80. The 16A 2-phase 8KV system I am looking at now is around $30. For non-certified, home project stuff, what I have is fine.
Would really like to see some other brands run on it. Not low cost ones like I tested but ones that people just assume are good because they cost so much. Not thinking there are too many that would want to play this game. For those meters, it may be best to just stay with the drop and bucket tests. :-DD
Would really like to see some other brands run on it. Not low cost ones like I tested but ones that people just assume are good because they cost so much. Not thinking there are too many that would want to play this game. For those meters, it may be best to just stay with the drop and bucket tests. :-DD
I would really like to send you a Brymen BM829s, but it will cost me $80 to send it, plus the cost of the meter. It would be cheaper for me to build a pulse tester myself. I have around 10,000amps available at 48V with an impedance of around 0.1 ohm or less, and a neon transformer. The two don't work together but I would, like to build something that will do the job. The problem is that here in Chile it is hard to get anything, and loooooon time to get anything into the country.
I have around 10,000 amps available at 48V with an impedance of around 0.1 ohm or less, and a neon transformer. The two don't work together but I would, like to build something that will do the job.
I would really like to send you a Brymen BM829s, but it will cost me $80 to send it, plus the cost of the meter. It would be cheaper for me to build a pulse tester myself. I have around 10,000amps available at 48V with an impedance of around 0.1 ohm or less, and a neon transformer. The two don't work together but I would, like to build something that will do the job. The problem is that here in Chile it is hard to get anything, and loooooon time to get anything into the country.
I tried to see if it was available through Amazon. Is it possible there are rebranded versions that you know would be identical?
Please don't let my small test box fool you. It may seem like I did all this testing so fast that what I have shown is trivial. There was a lot of time invested, not to mention the cost and dangers involved. This isn't your little insulation tester. If you make a mistake, you may end up paying the ultimate price! There is a reason I have not disclosed any information about how it is built. I don't want unskilled people to play with this stuff thinking that there is no risks involved!
I would also like to point out that with the lack of standards on how to test them, using the IEC 61010 surge may not be the right way to evaluate them. Making a tester that is not calibrated to a NIST standard may not give your customers confidence in the data you take.
I would really like to see more electrical testing in reviews and would like to see something like this but I am just not sure this is the right answer.
I have around 10,000 amps available at 48V with an impedance of around 0.1 ohm or less, and a neon transformer. The two don't work together but I would, like to build something that will do the job.
48V at 10,000 Amps for what length of time?? Do you just have a large capacitor bank that you are charging, and then discharging. What do you use that for??
Believe me, I am very familiar with high voltage with some good current behind it. I was the engineering manager for a scientific equipment company. I designed, helped build, and commissioned equipment that had 10kV 1A DC 100% duty cycle power supplies, 5kW RF power, and both combined. They also had electron beam gun heated crucibles that had 1-5kv bias on 200amp current for the filaments. I also had to build and certify the equipment to CSA special installation requirements.
I understand fully what kind of circuitry you have on those boxes, just not the details.
Greenelee has the DM830A:
http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a (http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a)
Which is the BM829 re-branded. The price right now is much higher than the BM829S.
http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a (http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a)
QuoteBelieve me, I am very familiar with high voltage with some good current behind it. I was the engineering manager for a scientific equipment company. I designed, helped build, and commissioned equipment that had 10kV 1A DC 100% duty cycle power supplies, 5kW RF power, and both combined. They also had electron beam gun heated crucibles that had 1-5kv bias on 200amp current for the filaments. I also had to build and certify the equipment to CSA special installation requirements.
I understand fully what kind of circuitry you have on those boxes, just not the details.
This should be a walk in the park for you then. I look forward to seeing your setup.
QuoteGreenelee has the DM830A:
http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a (http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a)
Which is the BM829 re-branded. The price right now is much higher than the BM829S.
http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a (http://www.amazon.com/Greenlee-DM-830A-Digital-Multimeter-1000/dp/B003TO5YUU/ref=sr_1_1?ie=UTF8&qid=1435975207&sr=8-1&keywords=greenlee+dm-830a)
I checked the links. It's a bit too high priced for me just to run it against the Fluke 101.
Happy 4th of July!!!!!
It seems like a good day to blow stuff up with a homemade surge generator....
Do any of you guys have transformers that can deliver 600 to 1000V with some decent current behind it? My 1000V transformer can only supply 500mA, and that is not enough energy for this testing. Maybe this would be easier to test with DC? Lightages could charge those batteries up to 1000V, and see how long meters could survive that with some decent current behind the voltage?
So, now that this testing is complete, what's next?
BUT, what is VERY likely to occur very often is users applying voltage to inputs that they should not (resistance, capacitance, amps, etc). The videos you see most often from Fluke and MG are meters catching fire from this mismatch. 2nd Edition of the standard allowed manufacturers to say what the input was protected to (like 240V on resistance, even though the meter can measure to 600V). 3rd Edition now requires the meter can not be a hazard if the full voltage gets put on any input. Since this is WAY more likely to happen, I wonder how many low end meters would survive this?
But is a 1000 or 5000 at several amps very likely? I can't answer that.
16.2 Multifunction meters and similar equipment
Multifunction meters and similar equipment shall not cause a HAZARD in any possible combination
of RATED input voltages, and settings of function and range controls. Possible HAZARDS include
electric shock, fire, arcing and explosion.
Conformity is checked by the following test.The maximum RATED voltage specified for any function is applied to each pair of TERMINALS in
turn, in every combination of function and range controls. The test source connected to the
equipment measuring TERMINALS during this test is limited to 3.6 kVA for measurement category I
or measurement category II. For measurement category III or measurement category IV, the test
circuit has to be capable of delivering 30 kVA.
During and after the tests, no HAZARD shall arise.
Multifunction meters and similar equipment are to be tested by changing the Function/Range Selector to all
possible settings while connected to the maximum rated source.
101.4 Functional integrity
After the voltage of 4.4.2.101 has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
I thought this was covered in 4.4.2.101 and 101.
Dave does a good job checking this on at least on some of the meters he reviews. He plugs them into the outlet (220) and runs them through their paces.
https://www.youtube.com/watch?feature=player_detailpage&v=bKvyoZa5J8Q#t=1968
(https://www.youtube.com/watch?feature=player_detailpage&v=bKvyoZa5J8Q#t=1968)
If we are talking real world, do you want to go higher than this? I think I could put something together fairly quickly if you want.
I can apply 1000V to each of the ranges, and even 5000V. It would only be with a few milliamps though. This did damage the UT61E but it does not demonstrate that the meter does not harm the user with these conditions. That would require something more like 1000V at 10 or 15 amps (or more) as would be available on a circuit of that type.
I should also say the fee is beyond reasonable. $340 for just the general part? So much for trying to protect the public. It is just a big cash grab, just like lawyers and accountants.:-+
4.4.2.101 covers just the mains terminal101 refers to 4.4.2.101. Mismatch of leads is covered in 101.3.
16.2 Multifunction meters and similar equipmentI would think this would be the limit of 4.4.2.101 as well but I am not sure.
Yes, I know Dave puts 220 on to some meters he checks, but that is like some of the meters you tested surviving a 2,000V surge, when it could see as high as 6,000.
I can get to 3000V with 500mA behind it,
Sorry but I am not getting your point. These are two separate tests. Two separate goals. Again, my goal was to determine which meters were more robust than others. I did this by increasing the energy supplied to all the meters and seeing at what point they failed. Again, this has nothing to do with safety or meeting the IEC standards. What Dave is doing (IMO) is more real world common testing. I have done just what he is testing to countless times.
Is 3000V at 500mA a common thing people measure with their handhelds? If your goal is only to damage them, I can pop the back covers off and I'll hang it on that neon sign transformer. Seems I have seen that sort of thing happen before! :-DD :-DD
If the goal is just to see if meters can survive common faults, I think we need to define what that is. We could turn to IEC, but all they have is "REASONABLY FORESEEABLE MISUSE". :-DD
If you can think of a test that is something that you feel is a common problem for the average handheld user, post about it.
Quote4.4.2.101 covers just the mains terminal101 refers to 4.4.2.101. Mismatch of leads is covered in 101.3.
To be clear then, you would like to test them to the 4.4.2.101?
To be clear, I don't want them tested to ANY standard. You, more than anybody, should get what I'm saying.Never assume I understand anything. :-DD :-DD
I don't want to test them to a standard, but section 101.3 of 61010-2-033 (attached at the end) would serve as a decent test to base the testing off of.
I don't want to test them to a standard, but section 101.3 of 61010-2-033 (attached at the end) would serve as a decent test to base the testing off of. This section talks of putting the highest voltage the meter can test on the mains, on putting that on every jack, and every switch position. It does not require the meter to survive, just not become a hazard.
101.3.1 General
Conformity is checked by inspection, evaluation of the design of the equipment, and as
specified in 101.3.2 to 101.3.3, as applicable.
101.3.2 Protection by a certified overcurrent protection device
During and after the test, no damage to the equipment shall occur.
101.3.3 Protection by uncertified current limitation devices or by impedances
During and after the test, no HAZARD shall arise, nor shall there be any evidence of fire,
arcing, explosion, or damage to impedance limitation devices or any component intended to
provide protection against electric shock, heat, arc or fire, including the ENCLOSURE and traces
on the printed wiring board.
https://www.youtube.com/watch?v=QEMCrGchLxs&feature=youtu.be
5. The tests should be done with the included test leads as they are part of the impedance path.But that's not what I see at all.
16.2 Multifunction meters and similar equipment
Multifunction meters and similar equipment shall not cause a HAZARD in any possible combination
of RATED input voltages, and settings of function and range controls. Possible HAZARDS include
electric shock, fire, arcing and explosion.
Conformity is checked by the following test.The maximum RATED voltage specified for any function is applied to each pair of TERMINALS in
turn, in every combination of function and range controls. The test source connected to the
equipment measuring TERMINALS during this test is limited to 3.6 kVA for measurement category I
or measurement category II. For measurement category III or measurement category IV, the test
circuit has to be capable of delivering 30 kVA.
During and after the tests, no HAZARD shall arise.
Multifunction meters and similar equipment are to be tested by changing the Function/Range Selector to all
possible settings while connected to the maximum rated source.”
NOTE If test probes are provided with the equipment being tested then they are to be used for the test.
Compliance is checked by testing to verify no hazard occurs when switching selector settings.
What I was referring to is this part that I have gleaned from other posts. Remember that I am only going on the parts that I have seen and they might be out of context.Quote16.2 Multifunction meters and similar equipment
Multifunction meters and similar equipment shall not cause a HAZARD in any possible combination
of RATED input voltages, and settings of function and range controls. Possible HAZARDS include
electric shock, fire, arcing and explosion.
Conformity is checked by the following test.The maximum RATED voltage specified for any function is applied to each pair of TERMINALS in
turn, in every combination of function and range controls. The test source connected to the
equipment measuring TERMINALS during this test is limited to 3.6 kVA for measurement category I
or measurement category II. For measurement category III or measurement category IV, the test
circuit has to be capable of delivering 30 kVA.
During and after the tests, no HAZARD shall arise.
Multifunction meters and similar equipment are to be tested by changing the Function/Range Selector to all
possible settings while connected to the maximum rated source.”
NOTE If test probes are provided with the equipment being tested then they are to be used for the test.
Compliance is checked by testing to verify no hazard occurs when switching selector settings.
QuoteTo be clear, I don't want them tested to ANY standard. You, more than anybody, should get what I'm saying.Never assume I understand anything. :-DD :-DDQuoteI don't want to test them to a standard, but section 101.3 of 61010-2-033 (attached at the end) would serve as a decent test to base the testing off of.
:-+QuoteI don't want to test them to a standard, but section 101.3 of 61010-2-033 (attached at the end) would serve as a decent test to base the testing off of. This section talks of putting the highest voltage the meter can test on the mains, on putting that on every jack, and every switch position. It does not require the meter to survive, just not become a hazard.
You did not include everything. The way I understand it, the DUT must survive. But again, I bet we would get different answers from the manufactures as well. No big deal. See below...Quote101.3.1 General
Conformity is checked by inspection, evaluation of the design of the equipment, and as
specified in 101.3.2 to 101.3.3, as applicable.
101.3.2 Protection by a certified overcurrent protection device
During and after the test, no damage to the equipment shall occur.
101.3.3 Protection by uncertified current limitation devices or by impedances
During and after the test, no HAZARD shall arise, nor shall there be any evidence of fire,
arcing, explosion, or damage to impedance limitation devices or any component intended to
provide protection against electric shock, heat, arc or fire, including the ENCLOSURE and traces
on the printed wiring board.
No matter how this meter is protected (I am treating it as a black box) it needs to survive the test IMO.
That aside... Watch the following as I amp up the 440V capacitor dump test....Quotehttps://www.youtube.com/watch?v=QEMCrGchLxs&feature=youtu.be
Does the 3rd edition and the supplements say anything about the need to use the test leads as supplied for the tests?
You did not post all of 101.3.3, which is the section that we would be talking about, because these inputs are protected by PTC's and MOV's, and not fuses, which is what 101.3.2 seems to refer to.
and not fuses, which is what 101.3.2 seems to refer to.101.3.2 is for certified overcurrent protection device. This can be more than fuses, or they would not state:
If the protection device is a fuse, ...I believe this is any certified overcurrent device as it states. This could be a PTC as long as it has been certified.
Read all of 101.3.3. It say the protection circuit could be damaged, b
During and after the test, ... or damage to impedance limitation devices or any component intended to provide protection against electric shock,...
QuoteRead all of 101.3.3. It say the protection circuit could be damaged, bQuoteDuring and after the test, ... or damage to impedance limitation devices or any component intended to provide protection against electric shock,...
I have no idea where you would see this as allowing the protection circuit to be damaged. :-// It is interesting how many ways a poorly written standard can be interpreted.
:-// It is interesting how many ways a poorly written standard can be interpreted.
QuoteRead all of 101.3.3. It say the protection circuit could be damaged, bQuoteDuring and after the test, ... or damage to impedance limitation devices or any component intended to provide protection against electric shock,...
I have no idea where you would see this as allowing the protection circuit to be damaged. :-// It is interesting how many ways a poorly written standard can be interpreted.
What about the line that stated "Any damage to a device used for current limitation shall be ignored"?????
Any damage to a device used for current limitation shall be ignored if other parts of the equipment were not affected during the test.
If a device used for current limitation is damaged, it is replaced before the test is repeated.
If you have a TUV safety inspector you work with, ask them next time if some product you are working on is safe. See what sort of response you get.
But, I have asked questions about standards on numerous occasions, trying to clear things up on standards. In areas where it did not seem clear, I ask specific questions about the meaning, and I have NEVER received a straight answer back. They will pretty much just do their testing, and tell you if you pass or fail. They never clarify the standard, probably because they don't know for sure either.
What’s the secret to Fluke’s success? You only need to look at what the Fluke 101 can’t do. Fluke’s budget meter doesn’t measure current. If you ever look inside a meter, you’ll usually find two fuses, one for measuring Amps and the other for all the other functions on the scope. There’s quite a bit of engineering that goes into the current measurement of a meter, and when it goes wrong you have a bomb on your hands. Fluke engineers rather intelligently dropped current measurement from this budget meter, allowing them to save that much on their BOM.
Now if I could just find a meter I like....
I think it will be hard to get ANY company to send a meter to anyone who's intention is to try and make it blow up. Even if they are 100% confident that it meets all safety standards and quality. The tests will be continued until failure and no company wants to help show its product failing, reasonably or not.
To be clear, I have NEVER asked Fluke or Keysight to send me a meter. What I have asked them is if they would warranty their products if they failed before the Fluke 101. I also provided them the link to this forum. Only one company responded (not Fluke or Keysight).
To be clear, I have NEVER asked Fluke or Keysight to send me a meter. What I have asked them is if they would warranty their products if they failed before the Fluke 101. I also provided them the link to this forum. Only one company responded (not Fluke or Keysight).
How are you contacting these companies? By sending an email to customer service from the website? A typical customer service person wouldn't have a clue what you are talking about, and be able to respond to you.
Looks like Hackaday picked up the story.
http://hackaday.com/2015/07/04/exploding-multimeter-battle-royale/ (http://hackaday.com/2015/07/04/exploding-multimeter-battle-royale/)
I was fine with what they wrote until this part:QuoteWhat’s the secret to Fluke’s success? You only need to look at what the Fluke 101 can’t do. Fluke’s budget meter doesn’t measure current. If you ever look inside a meter, you’ll usually find two fuses, one for measuring Amps and the other for all the other functions on the scope. There’s quite a bit of engineering that goes into the current measurement of a meter, and when it goes wrong you have a bomb on your hands. Fluke engineers rather intelligently dropped current measurement from this budget meter, allowing them to save that much on their BOM.
Which appears to have led to more confusion. If people would have watched the videos, they would have known that no meter from the CAT III group was damaged in current mode.
So, why does the 101 hold up so well? I suspect circuit design, layout and part selection. I have not taken this 101 apart but there is a video on youtube that shows the board. Talk about an air gap. But ... as much as it kills me to say it, even more than the design, I suspect the culture within the company demands the meters meet a very high level of standards. Again, some companies I contacted felt it was fine for a meter to not be functional after the surge test, while others require their products are not damaged. The real test is going to be to get a high end meter and run it through the same tests. That meter is going to have a lot more features than the 101.
Do we pull the trigger??? After all it should at least be as robust as the 101, right?nice! I dunno man.. Grats on the 87V though! :-DMM
Looks like Hackaday picked up the story.
http://hackaday.com/2015/07/04/exploding-multimeter-battle-royale/ (http://hackaday.com/2015/07/04/exploding-multimeter-battle-royale/)
I was fine with what they wrote until this part:QuoteWhat’s the secret to Fluke’s success? You only need to look at what the Fluke 101 can’t do. Fluke’s budget meter doesn’t measure current. If you ever look inside a meter, you’ll usually find two fuses, one for measuring Amps and the other for all the other functions on the scope. There’s quite a bit of engineering that goes into the current measurement of a meter, and when it goes wrong you have a bomb on your hands. Fluke engineers rather intelligently dropped current measurement from this budget meter, allowing them to save that much on their BOM.
Which appears to have led to more confusion. If people would have watched the videos, they would have known that no meter from the CAT III group was damaged in current mode. They would also know that I stopped testing the current mode early on because the generator was putting out enough to blow the fuses and I did not want to replace them. So all the meters were only tested using the modes that used the voltage input connections. They would also have noticed that the Klein Tools meter had even less features than the 101 and was beat out by even the AMPROBE that has far more features. The Gardner Bender meter failed in the first round of tests and where is it's current sense feature?
We can only run the tests, collect the data and post the results. If people want to slant the data, I can't fix that.
So, why does the 101 hold up so well? I suspect circuit design, layout and part selection. I have not taken this 101 apart but there is a video on youtube that shows the board. Talk about an air gap. But ... as much as it kills me to say it, even more than the design, I suspect the culture within the company demands the meters meet a very high level of standards. Again, some companies I contacted felt it was fine for a meter to not be functional after the surge test, while others require their products are not damaged. The real test is going to be to get a high end meter and run it through the same tests. That meter is going to have a lot more features than the 101.
I gave up on contacting the service groups at the main companies. If if blows I'll just return the thing and hope they warranty it. Now if I could just find a meter I like....
I think this was a conscious decision by Fluke because they knew they couldn't make a safe meter,I don't know if the Fluke 101 is a safe meter or not. I thought I had made it clear, but again, safety was never a criteria. I was only looking for the most robust meter out of the group.
Sorry but I disagree with you; It VERY MUCH is a big deal. It isn't about the current range being the weakest, that is never mentioned or discussed. It is about the BOM and space savings. The large HRC/HBC fuses are some of the most expensive things on the board and they are some of the biggest things on the board with the fattest traces. The money saved on dropping fuses from the BOM can be used for better higher quality component selection (while keeping the same profit margin) and the savings in space can be used to better route other traces, add cut-outs etc.The next model in the range is the Fluke 106. It has current measurement and it costs about 50% more. The physical size is very similar (12mm longer, 5mm wider).
It does have a standardized safety-level rating stamped on it. Fluke have shown themselves to be honest and conservative with their ratings.QuoteI think this was a conscious decision by Fluke because they knew they couldn't make a safe meter,I don't know if the Fluke 101 is a safe meter or not.
It does have a standardized safety-level rating stamped on it. Fluke have shown themselves to be honest and conservative with their ratings.QuoteI think this was a conscious decision by Fluke because they knew they couldn't make a safe meter,I don't know if the Fluke 101 is a safe meter or not.
QuoteI think this was a conscious decision by Fluke because they knew they couldn't make a safe meter,I don't know if the Fluke 101 is a safe meter or not. I thought I had made it clear, but again, safety was never a criteria. I was only looking for the most robust meter out of the group.
QuoteI think this was a conscious decision by Fluke because they knew they couldn't make a safe meter,I don't know if the Fluke 101 is a safe meter or not. I thought I had made it clear, but again, safety was never a criteria. I was only looking for the most robust meter out of the group.
This isn't an evaluation of your tests defining safety; I am saying THEIR thought process. While not intricately linked, robustness and safety do share some commonalities. Many good design practices to ensure a safe meter will also ensure a robust meter. This is to say that while the two do not have to be linked they can be. Additionally, knowing what we know about fluke, they take user safety very seriously, to the point that a meter that is robust is likely safe as well. But it is only likely, not proven.
I've had the 87V for a few days now and it's certainly not a great meter. Not a lot of features.You seem disappointed? Not sure which features you were expecting. It's a standard multipurpose industrial DMM with all the essentials. That's the point of it. That's why it's easy to use, boots fast, and that's why it has a long battery life and longevity.
I've had the 87V for a few days now and it's certainly not a great meter. Not a lot of features.You seem disappointed? Not sure which features you were expecting. It's a standard multipurpose industrial DMM with all the essentials. That's the point of it. That's why it's easy to use, boots fast, and that's why it has a long battery life and longevity.
Every feature it has is implemented well. Bar graph is fast, continuity latch is fast, and the UI is easy and quick exactly because it doesn't have a lot of features. 289 has a lot of features, but at the cost of a lot of compromises in day to day usability.
I'd probably look at Agilent meters if you're looking for featureful DMMs, because they pack tons of features in their meters of the same category.
Personally I think you're being harsh on it. I think it's the best all around no frills meter Fluke ever made.
I understand, hence the reason I suggested Agilent.I've had the 87V for a few days now and it's certainly not a great meter. Not a lot of features.You seem disappointed? Not sure which features you were expecting. It's a standard multipurpose industrial DMM with all the essentials. That's the point of it. That's why it's easy to use, boots fast, and that's why it has a long battery life and longevity.
Every feature it has is implemented well. Bar graph is fast, continuity latch is fast, and the UI is easy and quick exactly because it doesn't have a lot of features. 289 has a lot of features, but at the cost of a lot of compromises in day to day usability.
I'd probably look at Agilent meters if you're looking for featureful DMMs, because they pack tons of features in their meters of the same category.
Personally I think you're being harsh on it. I think it's the best all around no frills meter Fluke ever made.
Well that is the point of having different choices. He isn't that impressed and it is his money. There are other options and that is good.
So expect another boring video like the last few. One thing I plan to do is also test the leads supplied with the 101. Maybe that will add some excitement. :popcorn:Could it be done with the back off to see if there's any sparks?
I've had the 87V for a few days now and it's certainly not a great meter. Not a lot of features. But it does cost a fair amount of money and is pretty common.'Boring' is sort of the point with that meter.
Well the moment a few of you have been waiting for is near. I said from the beginning that I would put the winner of the $50 shootout against an expensive meter. I've had the 87V for a few days now and it's certainly not a great meter. Not a lot of features. But it does cost a fair amount of money and is pretty common.
Again, I have no plans to test beyond what I have done with the Fluke 101. I would expect the 87V to handle all of those tests and far beyond. I base that on the Fluke video I had linked to earlier where they were testing at 17KV. In other words, I plan to call it a draw after I am finished with these tests, unless something happens and the sky falls or the sun goes out. Don't worry, I won't be dropping it off a bridge to see if the LCD will crack. If it fails it will be from an electrical event.
So expect another boring video like the last few. One thing I plan to do is also test the leads supplied with the 101. Maybe that will add some excitement. :popcorn:
The 87V is a defacto standard in that class DMM, so these tests will attract attention from a lot of professionals, particularly if it fails :oWhat are the chances of failure? :-//
The 87V is a defacto standard in that class DMM, so these tests will attract attention from a lot of professionals, particularly if it fails :oWhat are the chances of failure? :-//
You seem disappointed? Not sure which features you were expecting. It's a standard multipurpose industrial DMM with all the essentials. That's the point of it. That's why it's easy to use, boots fast, and that's why it has a long battery life and longevity.
Every feature it has is implemented well. Bar graph is fast, continuity latch is fast, and the UI is easy and quick exactly because it doesn't have a lot of features. 289 has a lot of features, but at the cost of a lot of compromises in day to day usability.
I'd probably look at Agilent meters if you're looking for featureful DMMs, because they pack tons of features in their meters of the same category.
Personally I think you're being harsh on it. I think it's the best all around no frills meter Fluke ever made.
I expect low. But we can't know for sure unless we try a surge test and demonstrate it, then its not just an educated guess. Many things can change over time and cause problems in new DMMs versus prior runs of the same model. A test of just one meter can be criticized, but its better than nothing.
This is one reason in the past, say in the US military, samples of a procurement were tested per batch by independent military labs to insure they live up to their specification, but I don't know if they still do this.The 87V is a defacto standard in that class DMM, so these tests will attract attention from a lot of professionals, particularly if it fails :oWhat are the chances of failure? :-//
So expect another boring video like the last few. One thing I plan to do is also test the leads supplied with the 101. Maybe that will add some excitement. :popcorn:Could it be done with the back off to see if there's any sparks?
The 87V is just over $400 now on Amazon. For that price, I am disappointed in what the meter can and can't do.
QuoteThe 87V is just over $400 now on Amazon. For that price, I am disappointed in what the meter can and can't do.
That is why I suggested a Brymen BM829 (Greenlee DM830) or a BM869 (Greenlee DM860). For the price, their functionality is hard to beat. The Keysights are good too of course.
The 87V is just over $400 now on Amazon. For that price, I am disappointed in what the meter can and can't do. Really what it comes down to is if the 87V is at least as robust as the 101.The price seems to have spiked recently for some reason.
BM829 doesn't have a latched continuity test nor does it have auto hold, which in my view are essential features for a DMM. So I fail to see how their functionality is hard to beat, when pretty basic and commonly used features are missing.QuoteThe 87V is just over $400 now on Amazon. For that price, I am disappointed in what the meter can and can't do.
That is why I suggested a Brymen BM829 (Greenlee DM830) or a BM869 (Greenlee DM860). For the price, their functionality is hard to beat. The Keysights are good too of course.
One year warranty only,Greenlee is lifetime, as has been said many times
no AutoHold feature, no latched continuity, short battery life, Peak hold 800mS minimum transient only, no Null in central position on the bargraph, double the burden voltage on mA, lower diode test voltage, tiny selector switch. There is a lot not to like on the Brymen meter, compared to the Fluke 87V.Yes, everyone has their preferences. There are many benefits to the Brymens (Greenlee) that the 87V does not have. I do not want to have to list them again for the nth time, but I guess I need to.
In my view, the lifetime warranty alone is worth the price difference.And again if that is the main worth, the Greenlee rebadges have lifetime warranty too.
BM829 doesn't have a latched continuity test nor does it have auto hold, which in my view are essential features for a DMM. So I fail to see how their functionality is hard to beat, when pretty basic and commonly used features are missing.
better DC and AC volts accuracy, better DC and AC current accuracy, AC+DC TRMS selectable on volts and amps, dual display,Better spec sheet accuracy which doesn't mean much. We all know Fluke, Keithley, Keysight add a lot of margin in their accuracy figures. Brymen certainly hasn't been around long enough to earn that reputation.
better DC and AC volts accuracy, better DC and AC current accuracy, AC+DC TRMS selectable on volts and amps, dual display,Better spec sheet accuracy which doesn't mean much. We all know Fluke, Keithley, Keysight add a lot of margin in their accuracy figures. Brymen certainly hasn't been around long enough to earn that reputation.
50K+ resolution on a DMM is overrated. Brymen BM869s is missing essential features that are actually important on a DMM. 87V doesn't just have a better battery life it has at least 4 times better battery life.
Greenlee is lifetime, as has been said many timesAgain, I have searched on Greenlee's website and there is no concrete number of years as to what "lifetime" means like Fluke's warranty (Fluke 87V is minimum 10 years to buyer who purchased from authorized Fluke dealer).
I am speaking purely pragmatically about Brymen here.better DC and AC volts accuracy, better DC and AC current accuracy, AC+DC TRMS selectable on volts and amps, dual display,Better spec sheet accuracy which doesn't mean much. We all know Fluke, Keithley, Keysight add a lot of margin in their accuracy figures. Brymen certainly hasn't been around long enough to earn that reputation.
50K+ resolution on a DMM is overrated. Brymen BM869s is missing essential features that are actually important on a DMM. 87V doesn't just have a better battery life it has at least 4 times better battery life.
Brymen has been making Amprobe, Extech and other brands for many years. How long is not long enough?
You are demonstrating your preferences, and that is fine. You are also making assertions without facts based on your preferences. OK, whatever.
Lifetime Limited Warranty
Greenlee Textron Inc. warrants to the original purchaser of these goods for use that these
products
will be free from defects in workmanship and material for their useful life, excepting normal wear and
abuse. This warranty is subject to the same terms and conditions contained in Greenlee Textron Inc.’s
standard one-year limited warranty
Useful Life is the expected period of time, in years, during which a depreciating asset will be productive. It is the number of years, as set by the IRS, that depreciable business equipment or property is expected to be in use. The IRS has a depreciation table for almost every item, including computers, vehicles, and other equipment.
I just think it's misleading suggesting Brymen 869 as an alternative to 87V as this super bargain with tons of features without also mentioning its major shortcomings.
Greenlee sells pipes and fishing gear. Who is to say they will still sell rebranded Brymen meters 10 years down the line?
Not having a latched continuity or auto hold or a much shorter battery life aren't preferences. They are real shortcomings on the Brymen 869 part when compared to 87V.I just think it's misleading suggesting Brymen 869 as an alternative to 87V as this super bargain with tons of features without also mentioning its major shortcomings.
It has shortcomings to you, just as the 87V has shortcomings to others. I have stated many times what are the advantages of the 87V and other Flukes. I just did again in this thread. What you like, others don't care. What others like, obviously don't impress you much neither. It is demonstrably true that the BM869s has more features and more accuracy than the 87V and for a lower price. It is also demonstrably true that the 87V has some features that are preferred over everything that the BM869s has. One person's preference should not dictate the "truth".
Again they are not preferences. Try to acknowledge faults in your own products and you might have better arguments.Until you attempt to walk the tightrope of a supplier vs a keen electronics enthusist you'd never know.
Brymen has its merits. I've also stated in the past, if one of the features it offers are a must then yes. Also the price is pretty compelling. And frankly compared to $400+ on a Fluke 87V I can absolutely see it being a better buy in some cases.Again they are not preferences. Try to acknowledge faults in your own products and you might have better arguments.Until you attempt to walk the tightrope of a supplier vs a keen electronics enthusist you'd never know.
We select products WE can stand behind, have confidence and trust in, AND KNOW there are many that for one reason or another cannot see what we see and rightly so, have their own opinions.
Is X product better than Y product, of course it is.
Beauty is in the eye of the beholder, it is a lesson we must all learn.
Live and let live.
Again accusations of me lying to sell product. You guys are really something. You make assertions based only on your preference and call anyone else who does not agree not educated. Logical fallacies and ad hominem attacks always demonstrates something doesn't it?
Sorry joeqsmtih for suggesting you might be happier with the BM869s when you stated your disappointment with the 87V. Obviously your opinion is worthless to them too and my suggestion was uneducated and only in my interest.
I will not contribute anymore to polluting your thread by arguing. Sorry it came to this. Your hard work and time deserved more respect.
I have to say one more thing and then I am done on this topic. Perhaps I was too harsh on Lightgages.
We all have our biases, but he's generally a really helpful part of this community and I think it was unfair of me to call out his conflict of interest in the exchange.
It was a cheap shot and I should be better than that. Sorry Lightgages.
BM869s with one year warranty: $310 or less shipped worldwide
Hopefully you can get your 87V repaired.
You didn't I missed that part, somehow. |OHopefully you can get your 87V repaired.
He did in the video. Unless I dreamt it since I was watching the video in bed.
Joe, sit back and have a well deserved rest.
Great work, we are all in your debt.
:clap:
That 101 can sure take the abuse. Nice conclusion to the tests.
Were you testing at 12Kv? (not sure if that was the latest iteration of your transient generator box).
I'd still give good marks to the 87V in that test. No arcing, failure in one range of a non voltage measurement function. Way beyond the point of where all the other meters failed (3Kv?).
Hopefully you can get your 87V repaired.
That said however, I would hardly call a one-off test of this sort any definitive test of a meter's robustness.
If 100 fluke 87s had been compared to 100 101s across a variety of controlled tests then you might be able to make a valid conclusion about their relative "robustness".
Sure, if the Fluke 87 had failed spectacularly at a relatively low voltage that might say something, but that's not what happened.
Yeah I since watched the whole video. (spoke too soon).
I agree $400 is too much for an 87V. It was around $350 when this thread started. And even that was a bit steep, but ok.
So we can conclude that 101 is one hardy meter. Is it because of the lack of features that it's as robust? Perhaps.
How robust is 87V really? Is 13Kv just above its threshold of what it can take or is it just like all the other meters? We can't really say.
We know 87Vs have a reputation for robustness. And I or anyone else certainly can't ask for much more from you. You've provided great tests in all of this.
Some parts are supposed to fail (like the fuses) and this is why meters will have reinforced blast shielding in some sections. But it would take way too many resources to really measure all these variables.
Fluke doesn't seem to have creepage issues for instance (like arcing at the selector), which many of the cheap meters exhibited at far lower voltages. And perhaps some features are difficult to implement without leaving the meter exposed to transient vulnerability in a given mode.
So what I take from this is. A well designed simple bare minimum feature meter will have a better chance of surviving than a feature packed bargain. Fluke designs some good meters. But just because a meter is expensive doesn't make it more robust. The added features make it potentially more vulnerable to damage when exposed to unforeseen circumstances.
This doesn't change my mind on the 87V though. It anything it reinforces what I've been saying. A meter with a smaller set of well implemented core features is better than a feature packed meter with less well implemented essential features, because I think that more features increases the number of transient failure vectors.
Fluke 101 is just an extreme example of this. A meter with half of what I consider essential features, is practically indestructible.
Because after all both of these meters come from the same company. And I would imagine they used the same philosophy and know how to design both of these meters. One just happens to be much more capable and expensive meter.
Yet in several of your posts you seem to be making that claim.That said however, I would hardly call a one-off test of this sort any definitive test of a meter's robustness.
If 100 fluke 87s had been compared to 100 101s across a variety of controlled tests then you might be able to make a valid conclusion about their relative "robustness".
I assume you did not watch the entire video as this is what I stated in the conclusion.
This testing was all funded by me, using my time to design the generator and run the tests. There is only so much I can do as one person. From your comment, I assume you are willing to take it to the next step. If not, that's fine too.
.Yes, I realize that and I was not claiming otherwise.
Early on I also stated I had no desire to put out enough energy to cause "spectacular" failures. There really was no point in this.
I agree, if people want a robust meter, they should spend $50 on the 101 and not $400 on the 87V.
I have no interest in doing such testing myself.And why does this not surprise me??
Is one not allowed to comment or point out limitations of a test?Pointing out what I have already pointed out is pointless but if you feel there is a point to it pointing, point away... :blah: :blah: :blah:
Yes, you have stated many of the limitations yourself but you also repeatedly make generalized conclusions based on the tests which I find unjustified.
I agree, if people want a robust meter, they should spend $50 on the 101 and not $400 on the 87V.
But what if someone wants a robust full featured meter? Agreed that based on your testing the Fluke 101 appears to be a very robust pocket meter. I think your testing surprised a lot of people on how robust that little meter is. But its features are limited.
My point was that only a failure at a lower voltage with arcing or something of danger to the user would present any meaningful knock on the 87V's "robustness".
I am 100% surprised that the 87V did not survive the same treatment as the 101.
...101 sure impressed, but I was also impressed by the Amprobe 510 which failed from much less of a transient than 87V. In fact your tests made me recommend it to a few people. I think it's a great little meter for someone just starting. That's the perspective I am coming from, not some spin.
Your poor experience with a 40 year old Fluke bench meter certainly stands but that's a bit apples and oranges comparison. Great progress has been made in almost every aspect of electronic design and manufacturing since then. 4-6 layer PCBs, components with built in protection, more focus on safety, CAT safety standards... the list goes on. I think back then the DMM industry was still trying to pull of a working DMM design off the ground, and they were still coming up with features we take for granted today. It's a bit unfair to paint today's products on account of shortcomings of products from 40 years ago.
101 sure impressed, but I was also impressed by the Amprobe 510 which failed from much less of a transient than 87V.
Also 13Kv is nothing to sneeze at. That's quite a bit more of a transient than what all the meters that failed next to 101 were subjected to.
87V survived that same 13Kv zap in all the modes but the Ohm mode. I think that's pretty darn good. It's well beyond the CAT IV spec, which doesn't even cover wrong modes.
I think 87V did well. Not as impressive as 101 but still pretty good. I got both meters. 101 is a cool little meter, but it's not at all in the same league in terms of usability as the 87V.
... now I know 87V can safely survive 13Kv transients, provided I use the right mode :)
...the Amprobe 510 which failed from much less of a transient than 87V.Of course, the AMPROBE was tested from the beginning, the 87V was not tested until the end. The 87V was never tested at lower voltages so we do not know where it fails. It may have failed at 2KV. We don't know.
I am not "twisting any data". Fluke 87V didn't fail at 3Kv, it wasn't tested at it. But we know for sure that UT and Amprobe failed at 3Kv.You imply the 87V failed the surge test on ohms, this is a presumption as operational checks were not done UNTIL the end of all surge tests, so who knows when/how ohms got nuked.
Given the experience with Fluke meters [made in this century] including the 101 I simply give it a benefit of the doubt.
Where did I ignore that ohms was nuked? Did I say it wasn't? Pretty sure I acknowledged it.I am not "twisting any data". Fluke 87V didn't fail at 3Kv, it wasn't tested at it. But we know for sure that UT and Amprobe failed at 3Kv.You imply the 87V failed the surge test on ohms, this is a presumption as operational checks were not done UNTIL the end of all surge tests, so who knows when/how ohms got nuked.
Given the experience with Fluke meters [made in this century] including the 101 I simply give it a benefit of the doubt.
The fact is OHMS was nuked and to ignore this is twisting the data.
There is no way I would trust my life with the 87V. That may seem like an unfair comment to a few of you but again, as so many of you have pointed out, what is my life worth. It sure seems like there were a few that were quick to point out that spending more money buys safety. Well my life is worth a lot more to me than risking it with a meter that I know fails at a lower energy than a $50 meter.
As I stated before, I would not trust any meter without personally testing it. I also have said I would never work on 440 and that I'm not trained for this.There is no way I would trust my life with the 87V. That may seem like an unfair comment to a few of you but again, as so many of you have pointed out, what is my life worth. It sure seems like there were a few that were quick to point out that spending more money buys safety. Well my life is worth a lot more to me than risking it with a meter that I know fails at a lower energy than a $50 meter.
This logic does not follow for me. Would you trust your life with the 87V if the 101 never existed, or you had never tested it?
How does the cost of one particular meter affect how much life-trustiness you would put in a different meter?It doesn't.
Would you trust your life to the Extech that you gave the testimonial about at the end-- the same one you said you wouldn't subject to the tests?At most I use it to measure 220 line CAT II stuff which I do not consider high risk. Even that is rare for the work I do. So to answer your question, no.
There is no way I would trust my life with the 87V. That may seem like an unfair comment to a few of you but again, as so many of you have pointed out, what is my life worth. It sure seems like there were a few that were quick to point out that spending more money buys safety. Well my life is worth a lot more to me than risking it with a meter that I know fails at a lower energy than a $50 meter.
This logic does not follow for me. Would you trust your life with the 87V if the 101 never existed, or you had never tested it?
How does the cost of one particular meter affect how much life-trustiness you would put in a different meter?
Would you trust your life to the Extech that you gave the testimonial about at the end-- the same one you said you wouldn't subject to the tests?
As I stated before, I would not trust any meter without personally testing it. I also have said I would never work on 440 and that I'm not trained for this.There is no way I would trust my life with the 87V. That may seem like an unfair comment to a few of you but again, as so many of you have pointed out, what is my life worth. It sure seems like there were a few that were quick to point out that spending more money buys safety. Well my life is worth a lot more to me than risking it with a meter that I know fails at a lower energy than a $50 meter.
This logic does not follow for me. Would you trust your life with the 87V if the 101 never existed, or you had never tested it?QuoteHow does the cost of one particular meter affect how much life-trustiness you would put in a different meter?It doesn't.QuoteWould you trust your life to the Extech that you gave the testimonial about at the end-- the same one you said you wouldn't subject to the tests?At most I use it to measure 220 line CAT II stuff which I do not consider high risk. Even that is rare for the work I do. So to answer your question, no.
I do think you are being at best imprecise and at worst quite wishy-washy with your conclusions.
As I read your words, you are essentially concluding that since the $50 fluke did not (seemingly/immediately) fail at a specific extreme test voltage, a more expensive meter that did (seemingly/immediately) fail at the same specific extreme test voltage is not safe.
If the 87V fails in some spectacularly minor way (with a test sample of one), when subjected to conditions far exceeding its ratings, I think it is not fair to conclude that it is not a safe device--That you wouldn't "trust your life with it". Basically, I consider your argument to be a non sequitur.
Do I think using the 87V places me at a higher risk than the 101, yes because it failed at a test that the 101 survived
Bottom line: Connecting a multimeter up to a genuinely high energy device is dangerous. You need to think very carefully about how you approach it.Power electronics is not a job for everyone...You must be qualified...
The best approach is not to do it at all and Waltzing up to it with a probe in either hand and the meter between your teeth isn't the way to go even if you did pay $5000 for the meter.
These tests are interesting but do not correspond with reality.
As an engineer in power electronics, what especially interests me is what happens with the multimeter when measuring a voltage like 550VDC on a 5000A DC drive and that there is an arc in the multimeter which occurs due to a transient voltage.
When there is great power in play, things go completely differently from what is seen in this test.
The simple harmless arc turns into a real explosion.
Therefore, on one hand, high voltage transients are not interesting because they are improbable, on the other hand, it is irrelevant whether or not the meter is still functional, what matters is that the operator has not been hurt nor killed.
We've only seen one set of test conditions. The 101 might fail much more catastrophically than the 87V in real high-energy situations.
From a safety perspective, it unclear to me how much value there is in a test that introduces a transient without the underlying mains voltage.Welcome to the forum.
My understanding, dating from some companies long ago mandatory safety training, is that the serious danger is that the transient establishes an arc and the underlying voltage sustains it. The video tape backed this up with lots of electrical road kill photos.
I never ended up working with high power and have never experienced transient induced arcing in real life though.
I expect low. But we can't know for sure unless we try a surge test and demonstrate it, then its not just an educated guess. Many things can change over time and cause problems in new DMMs versus prior runs of the same model. A test of just one meter can be criticized, but its better than nothing.
This is one reason in the past, say in the US military, samples of a procurement were tested per batch by independent military labs to insure they live up to their specification, but I don't know if they still do this.The 87V is a defacto standard in that class DMM, so these tests will attract attention from a lot of professionals, particularly if it fails :oWhat are the chances of failure? :-//
This is an excellent point. I was very happy when another member took it upon themselves to run similar tests on the 101 (Well, that is until I stepped things for that last round :-DD). I would like to see a second 87V tested as well just so we have two data points. Even then, that's too small of a sample size. I'm sure Fluke already has the answer as that video made it sound like they test every design to failure.
From what I understand from all of the posts I have read about the amount of money Fluke has invested in making their designs robust, and the 87V being a very popular meter and how long they have had to improve their designs, and again we are talking about it just doing as well as the lowest cost meter Fluke offers. It doesn't even have to exceed it! I assume the chances of a failure are very low.
From a safety perspective, it unclear to me how much value there is in a test that introduces a transient without the underlying mains voltage.
My understanding, dating from some companies long ago mandatory safety training, is that the serious danger is that the transient establishes an arc and the underlying voltage sustains it. The video tape backed this up with lots of electrical road kill photos.
The last major part is the controller for it. Watching Dave's last video on the old Fluke, I was thinking to use an MC6801. Another option I am thinking about is to run the thing headless and just use a PC with Labview.
The last major part is the controller for it. Watching Dave's last video on the old Fluke, I was thinking to use an MC6801. Another option I am thinking about is to run the thing headless and just use a PC with Labview.
Not sure what you mean by "use an MC6801" - build your own microcontroller?
These days almost everything is done with Arduinos.
Spent the day working some more on the wire wrapping and relearning the 6801 instruction set.Nice rats nest. :-+
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=170892)
That's going to be quite a bit larger than your old rig. Did you make that new case?
Impressive work. :-+
Wow... you've created a real stunner there - literally and figuratively. Looking forward to seeing this beauty in action.
what is the case? Not the wood part but the body. It looks REALLY nice.
Edit: The WHOLE thing looks really nice, I can't wait to see it destroy some meters.
what is the case? Not the wood part but the body. It looks REALLY nice.
Edit: The WHOLE thing looks really nice, I can't wait to see it destroy some meters.
Thanks. If you look back a page or so, you will see some pictures as I was making the case. It is 1/4" thick plate aluminum. After I had machined the face plate, I buffed it.
I'm liking the damage I see. Lets hope for more kaboom
Awesome! Not super surprised the uni-t's met their fate. It also goes to show how crap those EX series Extechs are. If I buy another, it'll be the E series (the rebranded Brymens). :popcorn:
Also, I'm really surprised that Fluke 107 is a different size from the 101. I figured they'd reuse the same chassis to save costs, but I guess not! That's fluke for ya: they don't cut costs to please their accountants.Adding amps measurement means it needs fuses inside.
From the pictures I have seen of the 101 and 107, they don't look at all the same. One look at the 101 and you can understand why it can survive the tests I have put it through.Yep. The 101 obviously has much more input protection. It will be interesting to see if the 107 survives as well as the 101.
Again, this was a VERY good call on your part. I doubt I would have bought this meter had you not recommended it.Aw, it was nuthin' :-[
Excellent! I'm rooting for that radioshack one. You can get it for $25 on ebay/amazon brand new. If it weren't for its pathetic 100 uF max capacitance range, it would be a really good all around meter WITH true RMS. I'm actually quite surprised it's gone this far.
I have a feeling that 107 will go the distance like your 101 did. :popcorn:
:popcorn:
The unpopulated spots on the UT61E make me wonder how the European TUV tested version of the UT61E handles. It has those spots fully populated and has beefed up fuses if I remember correctly.
joeqsmith:
I am rather impressed at the work and time you have put into these tests. Thank you very much for the time and effort, and cost! These tests certainly are weeding out meters that can't survive normal abuse, and not even abuse in some cases. Like I keep trying to tell people, the UT61E was capable of dying merely from walking around, and your tests kind of demonstrate that.
I am glad you like the BM869S so much and I hope it ends up at the end as one of the survivors.
5ky:
Thanks for throwing your money into the mix to get destroyed. This is a great service to all to learn what really is worth buying.
These tests certainly will demonstrate to people why they should consider spending money on good meters and not junk. From the tests so far, some meters will appear to be working right in some function but will be way off in other ways. This is a dangerous condition.
I have a feeling that 107 will go the distance like your 101 did. :popcorn:The 101 appears to have more input protection:
That chain forms the 10MOhm impedance on the voltage range.
7x 1.433MOhm precision resistor. The 107 must have it too, probably on the other side of the PCB.
I'm in the camp that damaged meter is a as-good-as-dead meter. If you know for a fact that some of the ranges are broken then how far can you trust the other ranges?
That chain forms the 10MOhm impedance on the voltage range.
7x 1.433MOhm precision resistor. The 107 must have it too, probably on the other side of the PCB.
Yep, I wondered if it has it them the other side of the PCB...can't find a photo though. Anybody have one they can open up and take a peek?
I'm in the camp that damaged meter is a as-good-as-dead meter. If you know for a fact that some of the ranges are broken then how far can you trust the other ranges?
I'm not following--did the 107 already take damage or something?
:-+...pic of 107The 107 must have it too, probably on the other side of the PCB.Yep, I wondered if it has it them the other side of the PCB...can't find a photo though.
I stand corrected. There are only three meters with partial damage... >:DI'm very sure you will fix that. >:D
That was entertaining.
5ky asked I return any of the working meters when I was done. I am trying my best to save on shipping costs!:-DD
I expect to make three more videos. One for 5KV, one for 6KV and then the finals using the original transient generator.:clap: >:D
What will people think if the Radio Shack meter survives what the 87V can't?:wtf: :o
And what about the Brymen?? Am I really going to put my own $230 Brymen meter on this generator just to see if it passes a test where the 87V failed?The cost of the Brymen and the Fluke 87V is miniscule compared to the time and effort you have put into this project thus far and because of that I'd be shocked if you didn't give them a taste of the evil lady. >:D
With the Fluke 101 need to share the spotlight? Will it just be the two Flukes or does the 101 really only pass because of it's lack of a current input? Many have asked why buy a Fluke if others are just as good. We know Flukes own 87V could not survive the final test. What will people think if the Radio Shack meter survives what the 87V can't? And what about the Brymen?? Am I really going to put my own $230 Brymen meter on this generator just to see if it passes a test where the 87V failed?
Where is that 87V now anyway? :)
Do it Joe, do it. :box:
For the record, the MM series by Extech are the Brymens.
Which Brymen are you referring to?
http://www.westwayelectricsupply.com/dm-860a-dmm-500k-counts-dm-860a.html (http://www.westwayelectricsupply.com/dm-860a-dmm-500k-counts-dm-860a.html)1. No stock? $325.00 is a good price, if available.
http://www.valuetesters.com/greenlee-dm-860a-digital-multimeter.html (http://www.valuetesters.com/greenlee-dm-860a-digital-multimeter.html)
http://www.globalindustrial.com/p/tools/test-measurement/Metrs-HVAC-R/dm-860a-industrial-digital-multimeter (http://www.globalindustrial.com/p/tools/test-measurement/Metrs-HVAC-R/dm-860a-industrial-digital-multimeter)
:box:
I don't like the Brymen red color. People might think I own a Uni-T or something. >:(Lifetime warranty, whatever that means at Greenlee.
Greenlee Green is a bit better, but a lot more expensive than Brymen Red. :-//
I don't like the Brymen red color. People might think I own a Uni-T or something. >:(
Greenlee Green is a bit better, but a lot more expensive than Brymen Red. :-//
The Brymen BM869s from TME was shipped to the USA in under a week for $235 US. They are in-stock. When I last looked on Amazon, the 87V was about $412 with shipping. To be honest, I really was not too concerned about the price. I knew what I wanted the meter for and what features I wanted. Even at the same price, I would have picked the BM869s over the 87V.
So many reviews on the BM869 but no one takes it apart. Sure, they pop the cover but no one was willing to go further. :palm: That won't be a problem. If I am willing to put 13KV to it, you know I am willing to take it apart. Stay tuned....
The Brymen BM869s from TME was shipped to the USA in under a week for $235 US. They are in-stock. When I last looked on Amazon, the 87V was about $412 with shipping. To be honest, I really was not too concerned about the price. I knew what I wanted the meter for and what features I wanted. Even at the same price, I would have picked the BM869s over the 87V.
So many reviews on the BM869 but no one takes it apart. Sure, they pop the cover but no one was willing to go further. :palm: That won't be a problem. If I am willing to put 13KV to it, you know I am willing to take it apart. Stay tuned....
I actually have one fully written up and proof-reading now. Full teardown and some performance analysis (no 13kV testing though lol), will post it soon Finally, got around to fixing my laptop so I can post it.
I was starting to think that you might have touched the business end of your new rig or something because we hadn't heard from you in a couple days :-DD
After all this, I am now interested in how the Flukes were designed so that they survive the 12kV pulse.
You seem full of praise for the Brymen and scorn for the Fluke 87V.Yes, I was wondering too.
If I understand correctly, they both failed at 13kV on the Ohms range only and were both fixed by replacing a couple of transistors.
Can you explain the reason for the dichotomy?
Exactly, I wonder what happens to the various MOVs PTCs ect when fed 12kV. It may be a simple gross overload, or possibly something more sinister such as leakage like non ideal behaviour that permits overload into sensitive areas.After all this, I am now interested in how the Flukes were designed so that they survive the 12kV pulse.
I don't think the secret is in the schematic.
A lot of the meters have the same level of protection but the MOVs and PTCs blew apart. The ones inside the Fluke didn't. Higher quality/better rated components in the Flukes...?
Also, the meters handled the 3 floor drop test better than I thought they would have. Did any come out without damage outside of scuffs/scratches/cracks?It would be very hard to say just how much damage was done during drop as the meters had all been pretty much destroyed beyond repair by this stage of testing. There was one meter that it tore an IC off the board during drop. Many of the LCDs were damaged. That Circuit-Test was the only somewhat working meter I dropped. It cracked the kickstand in half but really that meter held up very well which was why I gave it its own little segment. I really thought the the INNOVA would do nothing in the drop because it is so light but that was not the case.
I might have to get me a Fluke 107...
Exactly, I wonder what happens to the various MOVs PTCs ect when fed 12kV. It may be a simple gross overload, or possibly something more sinister such as leakage like non ideal behaviour that permits overload into sensitive areas.After all this, I am now interested in how the Flukes were designed so that they survive the 12kV pulse.
I don't think the secret is in the schematic.
A lot of the meters have the same level of protection but the MOVs and PTCs blew apart. The ones inside the Fluke didn't. Higher quality/better rated components in the Flukes...?
It's time for me to learn about MOVs and the other protection device's real properties.
You seem full of praise for the Brymen and scorn for the Fluke 87V.Yes, I was wondering too.
If I understand correctly, they both failed at 13kV on the Ohms range only and were both fixed by replacing a couple of transistors.
Can you explain the reason for the dichotomy?
I might have to get me a Fluke 107...
5ky has offered to allow me to continue to test the Fluke 107. Don't be too surprised to see in a later video. The things I did not like about the 101, like the ultra slow continuity test, lack of a backlit LCD were addressed, plus you can measure AC and DC currents. Still not a very feature rich meter but hard to argue how electrically robust it is.
I like the size. Small is good.
I'm after something small that will fit in my little suitcase along with a bunch of Arduinos and stuff but people will stay say "Oh, a Fluke!" when I pull it out :-DMM
The crowbar transistor circuit on the Ohms range isn't meant to survive any voltage above 1000V.
Well, its marked rating is 1000V.But as you know, "CAT III 1000V" rating requires an 8000V transient.
no circuit protection is required under IEC 61010 above that, except for the blanket 'no harm to the user'.
You said that, not Fluke. There is no point protecting a meter against imaginary threats, pushing up the price and bulk of a meter. Besides, IEC would have come up with more stringent recommendations, if they felt it was necessary, like they do, once in a while.Well, its marked rating is 1000V.But as you know, "CAT III 1000V" rating requires an 8000V transient.
http://www.ni.com/white-paper/5019/en/ (http://www.ni.com/white-paper/5019/en/)
I'm sure this is deliberate design by Fluke but it seems disappointing that their flagship meter is designed like that. Voltages over 1000V aren't that unusual, even in hobby work.
.no circuit protection is required under IEC 61010 above that, except for the blanket 'no harm to the user'.
But...aren't we always saying Fluke are expensive because they're above the very basic requirements. :-//
Brymen fan boys always brag about the low price, never about the 1 year only warranty. If the meters are so good, why don't you talk to your pals over there and find out why they don't offer a lifetime warranty? Now that would be interesting!
Greenlee new 1 year lifetime warranty: ::)
http://www.greenlee.com/support/warranty.html (http://www.greenlee.com/support/warranty.html)
(http://greenlee.ebizcdn.com/5f11b27f131494a1c014fcced2f13165)
Joe:Rubbish.
I was sincerely surprised to see the 87V fail on the ohms at 1.5kV. Was this the one that you repaired or a new one? This does not remove my confidence in Fluke in any way, but it was a surprise. It is not likely a test condition that the vast majority of people will come across so I don't see it as any negative against the 87V. A person making this error in real life tests should be to blame and maybe shouldn't be working with a multimeter unsupervised.
The fact that the BM869S failed at a higher voltage doesn't mean much neither. I would suspect variation in component manufacturer could have as much to do with the difference as the circuit design.
What was nice to see in both cases is that they were so easily reparable for so little expense.
No, the meters did not fail in an unsafe manner. The tests that Joe did couldn't even show that. Both Fluke and Brymen meet the safety requirements as spelled out by the IEC for their CAT ratings.I agree of course, but Joes tests were never about meter safety, only meter robustness.
The Fluke (and argueably the Brymen also) is just not robust enough.......do some power electronics with contactors or large inductors and subject a meter to back EMF and poof. :wtf:Yep. I was messing about with some little Neon lamps the other day and when there's no load on my little 5V->150V transformer the output goes over 1000V, no problem.
I hope Fluke is watching this thread... :popcorn:Does it matter?
Use a high voltage probe when voltages above 1000V are likely to be encountered.+1
in·sult
speak to or treat with disrespect or scornful abuse.
synonyms: abuse, be rude to, slight, disparage, discredit, libel, slander, malign, defame, denigrate, cast aspersions on, call someone names, put someone down.
I don't know why you feel insulted. I referred everybody to a new Greenlee warranty of 12 months for all their products . Maybe I should feel insulted for being wrongly accused of insulting people.
A limited lifetime warranty can be anything the manufacturer wants it to be, even 12 months.
If you have tangible information that the limited lifetime warranty for the Greenlee meters is longer, I'd be glad to modify my previous post with the exact number of years. I don't have a point of view. I'm only interested in facts.
I have never attacked Joe or yourself personally in any way. .................
The term 'Fluke fan boy' (his spelling) was used by Joe in an earlier post than mine (post 496)(1). Did you feel insulted? I didn't think so; it just characterizes people who are passionate about a particular item. Dave himself used the term UNI-T fanboys, referring to people who defend their meters, like myself. ................ He certainly didn't convey to me that he felt insulted by anything I said.
If anything, I have a lot of respect for Joe for being able to build a quality high voltage tester at such short notice and for fixing multimeters as fast as I can tie my shoelaces.
The Fluke (and argueably the Brymen also) is just not robust enough.......do some power electronics with contactors or large inductors and subject a meter to back EMF and poof. :wtf:
We've all made DMM range selection errors and subjected our meters to all sorts of abuse, sometimes it is just supidity, other times unexpected voltages. That the meter should protect you as per CAT or IEC ratings is a given, but simple user errors should not result in a :-BROKE :-DMM
For entry level meters to survive and flagship models not. :wtf:
Yep. I was messing about with some little Neon lamps the other day and when there's no load on my little 5V->150V transformer the output goes over 1000V, no problem.
(As measured with a $5 meter set to 1000V mode. It survived the spark...)
Yes, you have to set the Fluke 87V to Ohms mode to kill it that way, but still...not good.
I just happen to disagree with the way Joe is conducting tests on multimeters and inferring from them that the Fluke 87 is a lesser meter than the Fluke 101.
Any test engineer or working scientist knows that you can't draw any meaningful conclusion from testing with an n=1 (or 2) - so all this teeth gnashing about exactly what these tests ultimately prove is misplaced IMHO. They are certainly interesting and entertaining and make for a good discussion. I say well done Joe! (even though I know he has not tolerated my critique in the past). Joe's biases come through but that is not a criticism - we all have our biases. Any strongly held opinions about the 87V based on these tests are unfounded IMO but that's ok - we all have opinions..
For what it's worth, I can't think of any high-end meter that has an overvoltage protection above 1000V on the Ohms range. And I've read a lot of manuals to compile the multimeter lists.
Lifetime by itself doesn't mean anything. It has to be qualified for the product. Is it 5 years, 10 years, 20 years, 50 years after purchase? Is it transferable from one owner to the next?
Word of mouth is not legal, they should refer you to their proper lifetime definition on their multimeter documents.
This is Brymen's warranty terms. I don't see much difference compared to the limitations of Fluke's or Gossen's limited warranties. I expect Greenlee's warranty will follow the same guidelines. No company will cover the cost of repair for an item that has been misused by the user, unless by prior arrangement or goodwill on their part. (UNI-T fixed my multimeter under their 3-year warranty, even though I had modified it extensively):Lifetime by itself doesn't mean anything. It has to be qualified for the product. Is it 5 years, 10 years, 20 years, 50 years after purchase? Is it transferable from one owner to the next?
Word of mouth is not legal, they should refer you to their proper lifetime definition on their multimeter documents.
I agree with you, it is not clear. The definition of "useful life" can be defined as the period over which a capitol purchase is discounted to zero value for the purposes of tax write offs. This still doesn't help much but most companies would write off a multimeter after 5 years. I don't think that this is the definition that Greenlee is using based on my conversation with their service rep.
I am sorry, but the clearest answer I got from Greenlee service is that they will replace almost anything as long as it has failed not by fault of the user. A verbal agreement is as good as a written contract if you can prove the verbal agreement occurred, with a recording for example. I suppose that some boss at Greenlee could say that their employee overstepped his bounds and they will not honor his agreement.
The point is, IMHO, that Greenlee does have a lifetime warranty and it might not be as clear as some others, but the others also have lots of room to deny the claim also as has happened to some here. The room to avoid a warranty claim also exists in the Gossen link you showed. I have no vested interest in Greenlee.
So much salt, and no popcorn!
Today I will find the limits of your Fluke 107.
That's a 20KV 50us FWHH wave there with about 15J available..
I hate working with lead free solder.Then why on earth do you? It's muck.
Because everything is built with that crap now, including this 107. On the bright side, if I have the heat gun out, you know something didn't go so well for 5ky's Fluke.Oh dear. :o :-DD
Because everything is built with that crap now, including this 107. On the bright side, if I have the heat gun out, you know something didn't go so well for 5ky's Fluke.
Because everything is built with that crap now, including this 107. On the bright side, if I have the heat gun out, you know something didn't go so well for 5ky's Fluke.Oh dear. :o :-DD
Your improved evil lady is truly wicked. >:D
Will the 101 survive and be top of the heap?
I don't understand why anyone would use lead free solder for hobby work. :scared:
That doesn't mean you need to continue to use lead free. Dilute the lead free with lead containing solder and be done with it!
I don't understand why anyone would use lead free solder for hobby work. :scared:
That doesn't mean you need to continue to use lead free. Dilute the lead free with lead containing solder and be done with it!
:palm: No offense but I find how you derive conclusions very fascinating. :-DD The next video may help you understand my comment.
I hope to have it up in a couple of hours. Poor little Fluke never stood a chance....
Quote from: joeqsmith on Today at 06:06:44 AM
I hate working with lead free solder.
Then why on earth do you? It's muck.
I would be interested to see a 28IIEX put through these tests, as well as the Amprobe HD160C. Maybe we can come up with a group donation to add more meters to the junk pile.+1
It is still in dispute whether a meter needs to survive and function after the fault conditions as spelled out in the IEC requirements for multimeters, or if they only need to not cause harm to the user when the fault occurs.
From Joe's tests, no meter can be said to pass or not pass the IEC requirements since we do not know whether the meter needs to still function or only protect the user from harm as mentioned above. It probably can be said that certain meters would certainly fail the IEC requirements from the damage incurred by Joe's tests, which would predict a big flash over.
Fluke 15B is the meter I'd like to see play with the evil lady.
I can get one to Joe for USD75 and happily pay half.
Any takers?
15B, 17B same internals.
If people are really interested in testing more meters, maybe we could do a Paypal account or kick start for each meter people want to run.Paypal would be OK.
Nobody but Fungus seems to want to play. :--Fluke 15B is the meter I'd like to see play with the evil lady.
I can get one to Joe for USD75 and happily pay half.
Any takers?
15B, 17B same internals.
I was thinking the same thing (but one of the newer 15B+ and 17B+ versions...)
Also ... one of those old-school Fluke 27s. They're supposed to be pretty tough but I wonder if they'd hold up or not.
Paypal fine with me and I'll put some money where my mouth is. :DIf people are really interested in testing more meters, maybe we could do a Paypal account or kick start for each meter people want to run.Paypal would be OK
We need to know how many people are interested though. Let's have a show of hands...
Nobody but Fungus seems to want to play. :--
Planning to willfully damage a whole bunch of mainly very safe and expensive meters. And this to prove what again? You guys have gone mental. ::)Maybe...but if it's only a few $$$ then it's entertainment. People go to the cinema every day to watch them wreck nice cars, etc. :popcorn:
You stand more chances of getting pregnant than experiencing high transients on the Ohms range.The protection isn't just there for transients, it's there for when operators make mistakes.
It would be far more useful (and cheaper) for everybody, if meters with suspected bogus CAT ratings, were subjected to transients in accordance with the IEC regulations, to separate acceptable meters from the dangerous ones.
The protection isn't just there for transients, it's there for when operators make mistakes.
...
Would you lend somebody your Fluke 87 at an electronics club meeting if you could lend them a 107 instead?
I said I was interested, I kind of started the idea no?
A Fluke 15B+ would be good, as would a UT71D, UT171B, a Keysight, Hioki, Gossen, Yokogawa, and Ideal.
The protection isn't just there for transients, it's there for when operators make mistakes.
...
Would you lend somebody your Fluke 87 at an electronics club meeting if you could lend them a 107 instead?
That 107 is very hardened and I would have no problems at all about giving one to someone as a basic meter.
There is no point retesting a Brymen CAT IV 1000V meter which has a UL listing. Your testing wouldn't validate the CAT rating by any means, but offer some valid guidelines for people who can't afford meters with recognized CAT ratings.
As for trolling, if it means not agreeing with someone publicly, then I guess I am trolling. Live with it.
The protection isn't just there for transients, it's there for when operators make mistakes.
...
Would you lend somebody your Fluke 87 at an electronics club meeting if you could lend them a 107 instead?
That 107 is very hardened and I would have no problems at all about giving one to someone as a basic meter.
I also like the fact that there's no 250mA fuse that costs $12+shipping to replace.
Not one person had a working fuse on the 250mA range last time I did a 'bring your multimeter' day at the club.
If they blow the 10A fuse, well ... something else was probably going to blow anyway. The fuse might pay for itself by saving that thing.
OK, Joe, keep baiting. I am going to ignore you from now on. I just thought perhaps we had a different point of view, but you have now proven you are trying to troll me. :-DD:-DD
If you haven't seen it yet, DextersLab2013 posted a video using his new generator. Looks like it does a nice job on them.
It is useful.That 107 is very hardened and I would have no problems at all about giving one to someone as a basic meter.I also like the fact that there's no 250mA fuse that costs $12+shipping to replace.
Interesting and entertaining videos. Well done.
That said however, I would hardly call a one-off test of this sort any definitive test of a meter's robustness.
Sure, if the Fluke 87 had failed spectacularly at a relatively low voltage that might say something, but that's not what happened.
If 100 fluke 87s had been compared to 100 101s across a variety of controlled tests then you might be able to make a valid conclusion about their relative "robustness".
I do think the Fluke 87V is a bit overpriced at $400 compared to its competitors but that's a different issue.
In the end, any test with an n=1 is just anecdotal in nature and not evidence. But it does make for fun viewing an interesting discussion.
Any test engineer or working scientist knows that you can't draw any meaningful conclusion from testing with an n=1 (or 2) - so all this teeth gnashing about exactly what these tests ultimately prove is misplaced IMHO. They are certainly interesting and entertaining and make for a good discussion. I say well done Joe! (even though I know he has not tolerated my critique in the past). Joe's biases come through but that is not a criticism - we all have our biases. Any strongly held opinions about the 87V based on these tests are unfounded IMO but that's ok - we all have opinions..
In the first series of meters I mentioned that I had only tested one of each meter and that this was not much of a sample size. Obviously, we are never going to be looking at large same sizes for any of these reviews. Many benchmarks are performed with minimal sample sizes and in some cases, even one sample but it does not mean they are completely invalid or that we can not learn anything from them. Statisticians are rolling there eyes now.....
Let me start by saying that these products were obtained through normal channels. In most cases they were procured through Amazon. Why does this matter? Well, if say the manufacture sent me meters directly for these tests, how would we know that these products were not special in some way in order to bias the tests? So to be clear, in no case did Fluke or Brymen supply me with product for these reviews. This is what I don't like about regulatory groups. The companies ship the products to be evaluated. Many times these may not be the final production parts. They may need to make some changes and go back and forth a few times before they are certified. In the end, do we really know the product that was certified is what will be supplied to you and me? Or, will a MOV be removed to increase profits by some accountant. Maybe a part was changed out for a cheaper part of what they think is the same quality and the product was not re-certified because of cost, time, etc. So, because I obtain the meters my some means that the average person could, I am making some assumption that the meters I test represent the average meter.
Now this makes for another assumption. I assume that the manufacturer has their process under control. They may not and then my first assumption that my one meter represent the mean goes out the window. So we could say for example, the 87V I tested does not represent the average 87V. It was some outlier. Then we also say that Fluke does not have control of their process. Now I doubt they have a process control problem, but I don't know. I would more guess that the meter just does not handle the transient by design in these other modes besides voltage. It's a pretty old design when compared with the 101. I am sure they have learned a few things and have improved their designs. I have no data to back that up and am just giving them the benefit of the doubt.
In the case of the 101 being the only meter to survive my first round of testing, we had a member repeat these tests using a different meter and commercially available transient generator. The results were the same. Even at 12KV they could not damage the 101. I went further and increased the FWHH and added 1KV and still could not damage it. I have some level of confidence that the 101 is very robust. That said, I was not too surprised that the 107 survived this same test.
Now had say the Fluke 87V failed at 2KV and the Brymen BM869s at 2.5KV, I would say we are well withing the margin of error of my tests and the meters them selves (what brand of components, date codes, etc). But this is not at all what happened. We have one meter living at 6KV and one failing at 1.5KV. That's a pretty big window. I bet if I tested 100 pcs of each meter we could find some 87Vs that would live to 1.7KV and some Brymens that fail at 5.5KV. If the windows were much wider, I would really question their process and quality control.
The problem in gaining confidence in the tests is that we are no longer talking about low cost meters. I doubt that our members are going to run out and buy an 87V and BM869s knowing the 87V may be damaged at 1.5KV just to repeat the test and see which is more robust.
I don't believe I have skewed the results or biased the test towards one brand or another. Again, take it for what it is worth or feel free to step up to the plate and take a swing. I am open to what ever tests the group can come up with to help determine which meters are more electrically robust than others.
If you haven't seen it yet, DextersLab2013 posted a video using his new generator. Looks like it does a nice job on them.
:-+ >:D
thats just shy of 1700v, 185uF
it's a bit of a sledgehammer in comparison to your generator Joe, but it's good to show how well the blast protection might work :-DD
If we call what you have a sledgehammer, I would say mine is a tack hammer. And what PhotonicInduction has is a pile driver. :-DD
I bet the Fluke 101 and 107 would survive on your generator all day long. Much of the time I monitor the voltage to see what to meter is doing and many of them don't draw much until they get ready to fail. I would NOT hook your 87V to it!! That 1.7KV may be enough to push it over the edge. :-DD
I look forward to seeing more videos of it doing some meter damage and getting that thing to put out is maximum blast.
:-+ >:D
thats just shy of 1700v, 185uF
it's a bit of a sledgehammer in comparison to your generator Joe, but it's good to show how well the blast protection might work :-DD
Damn that looks promising. I love how when you hit that CEM, you can actually see lights cascading behind the board. A lot longer lived than I expected.
Is it bad that I am actually laughing at this? The power is a HUGE step up. :box:
Beautiful start to the case! Those binding posts though, hot damn.
Those are some beefy lugs.
Where did you get those rack handles.
I would like to get somewhere in the maybe a quarter cycle of a home feed. Say, 220v 200A 60Hz or just to see the effects on these dead meters before I recycle them.:-+ >:D
thats just shy of 1700v, 185uF
it's a bit of a sledgehammer in comparison to your generator Joe, but it's good to show how well the blast protection might work :-DD
Let's assume that is 267J at the connector with no sort of network and you can double that at the connector. I think this is roughly what I would like to see.
If I target say 1/4 cycle of a 440 line at 200A, that's 366J.
Because some of the meters do not arc until much higher voltage than what you have, my plan is to have a second low voltage high energy generator that is triggered from the high voltage transient of the first generator. Staying with a stored system and keeping the voltages low should keep it very small and somewhat safe.
I know it is still no where near the energy of what you could see in real life but it may provide some insight as to how these meters would handle a higher energy transient.
just catching up on your new build Joe, you really do finish off projects! Your new generators look beautiful, nice work... can we see inside the new higher energy unit, what volts/capacitance do you have in there? :-+,
i still have not figured out the point where the magstim fires, a load of 100k ohm and it wont, but 1k does, i can put a coil in parallel with the DUT but then i am wasting energy in the coil. Your approach to use low energy high voltage to trigger the main charge is interesting... much like a xenon flash tube circuit in a way
i am taking the magstim over to a friend tomorrow, see if we can figure out why i am only getting 1700v instead of 2800v on the cap... i am sure we'll get around to making some things expire too, maybe i should try the fluke 101? >:D
Finally got around to looking at this link showing the 15B+. That's a step up over the 101 and 107. I wonder if it is as robust. Any idea what it would take to get it sent to the US?Just money Joe.
http://www.aliexpress.com/store/product/Fluke-15B-F15B-Digital-Multimeter-Auto-Manual-Range-AC-DC-1000V-10A-40M-ohm-Capacitance-100uF/917544_1187715988.html (http://www.aliexpress.com/store/product/Fluke-15B-F15B-Digital-Multimeter-Auto-Manual-Range-AC-DC-1000V-10A-40M-ohm-Capacitance-100uF/917544_1187715988.html)
Looks like I can get it through Amazon. They also offer the 17B with a few more features.The only difference betwen the 15 and 17 is the front case and keypad membrane with the extra buttons.
http://www.amazon.com/SSEYL-Fluke-Digital-Multimeter-F15B/dp/B00SEZU4KO/ref=sr_1_4?ie=UTF8&qid=1447992356&sr=8-4&keywords=fluke+15b%2B (http://www.amazon.com/SSEYL-Fluke-Digital-Multimeter-F15B/dp/B00SEZU4KO/ref=sr_1_4?ie=UTF8&qid=1447992356&sr=8-4&keywords=fluke+15b%2B)
I'm not aware if the 15B is available directly from Fluke internationally. AFAIK the 15B is a China market unit only, those that I have got have no warranty outside China.
Would it be better to run the 115 or the 15B+? It seems like the 115 would be more common but the 15B+ may be a newer design.
Finally got around to looking at this link showing the 15B+. That's a step up over the 101 and 107. I wonder if it is as robust. Any idea what it would take to get it sent to the US?It's an Asian model, so... you have to buy on eBay/aliexpress/whatever.
As we know any unit that you get and expose to your lady devil >:D wil not be much good for further use so I'll put up USD50 if somebody adds the extra USD25 to get a 15B for you to test in the name of science. ;)
Tell us what you'd like Joe.
It's a little late to roast them for Thanksgiving but the the 17B+ is on it's way along with a few other meters. I like the features the 17 has and the cost was a wash.
It's a little late to roast them for Thanksgiving but the the 17B+ is on it's way along with a few other meters. I like the features the 17 has and the cost was a wash.
:-+
I own a 17B+ and am curious to see how it goes.
It's a little late to roast them for Thanksgiving but the the 17B+ is on it's way along with a few other meters. I like the features the 17 has and the cost was a wash.
:-+
I own a 17B+ and am curious to see how it goes.
Do you like it? Looks like a nice little meter.
That's a broad statement, don't you just mean it could be faster?It's a little late to roast them for Thanksgiving but the the 17B+ is on it's way along with a few other meters. I like the features the 17 has and the cost was a wash.
:-+
I own a 17B+ and am curious to see how it goes.
Do you like it? Looks like a nice little meter.
Yeap! Pretty solid, The only thing I think could be better is the continuity test. But still a very good meter.
"Pretty solid":-DD This thing feels very solid compared with most of the meters I have looked at. It's not at all what I was expecting.
That's a broad statement, don't you just mean it could be faster?
Someone had posted that the 17B and 17B+ were the same board. This is not the case at all. The 17B+ is aligned digitally, not with pots.Not I, but I did state the 15B and 17B have the same board, maybe you got you wires crossed Joe. :-DD
Someone had posted that the 17B and 17B+ were the same board. This is not the case at all. The 17B+ is aligned digitally, not with pots.Not I, but I did state the 15B and 17B have the same board, maybe you got you wires crossed Joe. :-DD
This has been mentioned in threads in the past, the only differences being a different front panel and 2 additional buttons on the rubber membrane for the extra functins of the 17B.
It wouldn't surprise me at all if the 15 and 17 B plus models shared the same PCB too.
Thank you all for the replies so far. Does anyone know if the continuity test on the new 17B+ latches on good or is still scractchy like what Dave tested on the review of the old 17B??AFAIK the internals are the same as a 15B and the continuity test is excellent for a cheap DMM
When it specified +3 counts, it is a bit confusing. It really means ±3 counts. Why they don't say it that way I don't know. So it really is ±80mv allowable error on the 40V scale.
Hi,
Has anyone a tool to make a digital alignment?
At 10VDC, my 15B+ reads 9.87, or -130mV error1) What are the specifications for your 10V and 40V reference?
At 40VDC, my 15B+ reads 39.52, or -480mV error, thats nearly a half a Volt!! :--
At 10VDC, my 15B+ reads 9.87, or -130mV error1) What are the specifications for your 10V and 40V reference?
At 40VDC, my 15B+ reads 39.52, or -480mV error, thats nearly a half a Volt!! :--
2) Are you using a variable power supply set at 10V and 40V for comparison to the Fluke?
3) If you hook another meter to the same 10V and 40V reference source, what readings do you get?
And yes, the 15B+ is also aligned digitally, not with pots, the older 15B has a pot to align.
Has anyone a tool to make a digital alignment?
1): 0.005% at VDC, good enough for a 15B+
2): no, the voltage is comming direct out of a Fluke 5100A
3): see pictures
And yes, the 15B+ is also aligned digitally, not with pots, the older 15B has a pot to align.
Has anyone a tool to make a digital alignment?
It wouldn't surprise me if Fluke deliberately doesn't calibrate them perfectly. It would really eat into 87V sales if they did. :popcorn:
PS: I was just searching the web and can't find anybody reverse engineering the calibration.
3): see picturesWow, the 15B+ is way out of spec (0.5% + 3 digits) at 9.84 and 39.40. Definitely :--
3): see picturesWow, the 15B+ is way out of spec (0.5% + 3 digits) at 9.84 and 39.40. Definitely :--
4) Was the 15B+ out of spec since day 1, brand new, or has this meter drifted over time?
off topic: I like the bigger digits compared to the 87V.
PS. I had to ask regarding your references because I had no idea what you had.
Here is my 17B+ review/test. It's long....
https://www.youtube.com/watch?v=DvC5woDYGd4&feature=youtu.be (https://www.youtube.com/watch?v=DvC5woDYGd4&feature=youtu.be)
DG5SAY, are all of the other functions in-cal?
Here is my 17B+ review/test. It's long....
https://www.youtube.com/watch?v=DvC5woDYGd4&feature=youtu.be (https://www.youtube.com/watch?v=DvC5woDYGd4&feature=youtu.be)
DG5SAY, are all of the other functions in-cal?
4): it was out of spec "since day 1"! I own it now for 6 months and it has not changed since then.I'm surprised you didn't ask for a replacement or refund from seller if it was out of calibration since day 1?
4): it was out of spec "since day 1"! I own it now for 6 months and it has not changed since then.I'm surprised you didn't ask for a replacement or refund from seller if it was out of calibration since day 1?
Here is my 17B+ review/test. It's long....
https://www.youtube.com/watch?v=DvC5woDYGd4&feature=youtu.be (https://www.youtube.com/watch?v=DvC5woDYGd4&feature=youtu.be)
DG5SAY, are all of the other functions in-cal?
Starts the video saying, I'm not going to do a full review....
Does a full review :-DD
That being said, nice review so far. Still watching/listening to it as I work on a document for work.
Sure, I did. But first, they don´t believe me. When I sent them my measurements, they offered me to exchange the multimeter. I should have sent it, however, at my own costs to China, clearly that I neither the device nor the money would have seen again! So I made a negative review and will never buy anything again from this eBay-Shop. End of the story. :--
Sure, I did. But first, they don´t believe me. When I sent them my measurements, they offered me to exchange the multimeter. I should have sent it, however, at my own costs to China, clearly that I neither the device nor the money would have seen again! So I made a negative review and will never buy anything again from this eBay-Shop. End of the story. :--
Sounds like you and the seller both had bad luck. What would you have done if you were the seller trying to sell multimeters with only one or two dollars profit margin?
PS: What happens if you turn the little trimmer next to the calibration connector? Does anybody know?
Ah.... The smell of good coffee and burnt UNI-T parts in the morning...:-DD
When I got the Brymen BM869s, I made a few videos where I was comparing it with a few Flukes. One was the 115. I did not know it was made in China until it arrived and I looked at the packaging. With it being a little older, I wonder if it will be less robust.Will a 115 be next on the bench Joe?
Yes, my plan is to run the 115 to failure next. If people find it helpful, rather than just running the tests I'll continue to do some sort of mini review of them to at least show how they compare against some of the surviving meters.When I got the Brymen BM869s, I made a few videos where I was comparing it with a few Flukes. One was the 115. I did not know it was made in China until it arrived and I looked at the packaging. With it being a little older, I wonder if it will be less robust.Will a 115 be next on the bench Joe?
Check to see if it too has that Gawd awful calibration connection like the 17+ :-- , you want to be able to tweak your DMM too, don't you?
Oops..... :palm:.....I haven't yet subscribed but we can soon fix that, a brilliant informative sequence of great videos, many thanks.... :-+
I have a couple of 117s and will need to check them again to see if there was any off mode current draw, I did test them once but cant remember and I religiously pull out the batteries when not in regular use, your 115 appeared to recover once the battery was removed and reinstalled the first time around but it may have been just a coincidence and something else altogether.
Kind regards.... :)
Muttley
Hey Joe, I have several people on another forum that want to know the EXACT specs of your HF test that blew the leads off. Specifically, FWHM, source impedance, was it the HV spike only or did it include the AC load as well, etc. Any details you can provide would be great. I have already been told I have an axe to grind because I panned the HF meter |O
i like the details on the Hz response of the continuity and the hysteresis. +99pts ! :P
Both "DESIGNED IN USA" but maybe they changed where they were made and corporate did not want to invest in having to re-certify them. :-//I think it's possibly because they changed the regulations and they didn't want to change their input v protection to recertify. That would be my guess.
It's more than the color.... Notice the ratings and serial numbers.
If Fluke made a meter with the features and battery life of the BM869s, electrical robustness of the 107, designed and made here in the USA and under 1K, I would be the first in line. That's coming from someone who would never have owned another Fluke until I started trying to damage them. :-DD Hard to believe Fluke would not mark them over money but then again, times change.
Here's the donated Greenlee. Looks like there are a few positive reviews on it:
http://www.amazon.com/Greenlee-DM-20-Ranging-Digital-Multimeter/dp/B000FRQO6C/ref=sr_1_1?ie=UTF8&qid=1450227983&sr=8-1&keywords=greenlee+dm-20\
(http://www.amazon.com/Greenlee-DM-20-Ranging-Digital-Multimeter/dp/B000FRQO6C/ref=sr_1_1?ie=UTF8&qid=1450227983&sr=8-1&keywords=greenlee+dm-20\)
An interesting looking meter, whats the COO?
An interesting looking meter, whats the COO?
Cost? I have no idea. Looks like the next higher up that replaced it is around $30. I assume it's a rebranded. Made in China, but looks like they could afford a UL listing.
What's interesting is that the fuse is still good.
Will have to test it with their leads. Last time I tried that with a cheap meter, it did not work out so well for the meter. :-DD Should be interesting.
Here's the donated Greenlee. Looks like there are a few positive reviews on it:
COO = Country of Origin (which you answered).
I am intrigued to see a teardown and testing of this meter. It looks VERY different than anything out there. Kinda fat and chunky in a weird way.
2000 count manual ranging, with the lowest ACV range being 200V, means the basic design is the same as your average "830" cheapie with a 7106 COB, maybe an extra opamp for continuity tester. Interesting, I see that Greenlee de-rated the high ACV range down to 300V, most cheapies are marked 500, 600 or even 750V. And omitted the usual hFE test socket. Did they beef up the input protection as well?
Here's the donated Greenlee. Looks like there are a few positive reviews on it:
As a side story, I use DMMs often on metal hulled ships. AC, even DC, is typically transient heavy enough to kill or severely injure DMMs, and I've experienced in use failures, but not explosions, with non-Fluke DMMs doing a typical measurement. Fluke DMMs tend to dominate use on steel hulled vessels. After Joe's test I've rerun some test myself and put the 101 seagoing conditions and its working very well, plus easier to pocket. Equipment has to be very reliable if depended on and one is in the middle of the Pacific for stretches of time. I've never seen side by side tests like Joe does here with different brands and models, and it clearly shows what you pay for.The Fluke 100 series seems quite unbeatable for reliable, safe, everyday usage (ie. non-EE work).
The Fluke 100 series seems quite unbeatable for reliable, safe, everyday usage (ie. non-EE work).
Joe easily shows Fluke's secret sauce, they will scrimp on functions, but they don't on surge protection even for their cheapest cataloged DMM [ I think as of this writing, its the 101].
As a side story, I use DMMs often on metal hulled ships. AC, even DC, is typically transient heavy enough to kill or severely injure DMMs, and I've experienced in use failures, but not explosions, with non-Fluke DMMs doing a typical measurement.
As a side story, I use DMMs often on metal hulled ships. AC, even DC, is typically transient heavy enough to kill or severely injure DMMs, and I've experienced in use failures, but not explosions, with non-Fluke DMMs doing a typical measurement.
This is very interesting. Could you provide more details about the cause of these transients and have you ever tried to characterize them?
hi joeqsmith
can i suggest doing a sideshow, to try whipping the surges at some protection components with your gear, the aim is that by modding say the UNI-T with additional tested MOV or TVS, it then passes your surge test ?
no i dont have circuit in mind. its just an idea because the UNI-T PCB always come with unpopulated MOV. if say by putting in the MOV, and it can stand up to some more surge, it could be good news for some DIY-ers who are interested to mod it but do not know the result for a real surge.
Here's the donated Greenlee. Looks like there are a few positive reviews on it:
That thing looks horrible. Awful screen. Range switch too small. Captive probes. :scared:
I predict the insides will be terrible and it will fail on the barbecue-lighter test.
I was looking at a Newport HHM290 meter today. What caught my eye was it measures inductance. Then I noticed the two thermocouple inputs plus IR temperature. Strange that they did not autorange everything. It make the BM869s look small if that's even possible.
http://www.newport.ca/Pdf/HHM290.pdf (http://www.newport.ca/Pdf/HHM290.pdf)
For those who are interested in knowing how the Greenlee DM-20 held up during my tests, enjoy.
https://www.youtube.com/watch?v=SIQuk0E6wdU&feature=youtu.be (https://www.youtube.com/watch?v=SIQuk0E6wdU&feature=youtu.be)
Joe, after downloading your spreadsheet, it is not clear just what each of the cell pass/fails represent. :-//
Members often ask of DMM recommendations, must they watch all your vids?
|O :palm:Joe, after downloading your spreadsheet, it is not clear just what each of the cell pass/fails represent. :-//
"Fail" = Magic smoke escaped at the specified voltage.Members often ask of DMM recommendations, must they watch all your vids?
You could try watching one of them... :-//
PS: They're not 'recommendations'. It only measures one tiny aspect of a multimeter (resistance to sparks).
|O :palm:
When I opened the spreadsheet FIRST time the Column titles DID NOT appear, hence the reason for my post.
All good now. :-+
Can I also say it seems obvious (at least to me) that the thread title has many overlook the excellent work you have done, but maybe not so with the addition of DMM in the title. :-\This has came up from time to time but no one has offered what they feel is a better suited title.
PS: They're not 'recommendations'. It only measures one tiny aspect of a multimeter (resistance to sparks).
Joe, I thought just the addition of "DMM" would enable more hits from a forum search:
Hear kitty kitty kitty, nope not that kind of cat. CAT III handheld DMM surge tests.
Anyway, I'll butt out now, please carry on with what history will show as magnificent work. :-+
After six years of use, my Mastech MS9508 / Cen-tech P37772 LCD was starting to become intermittent.:-DD
Notice that the LCD is starting to pop out. The On and Hold buttons are letting some photons escape. Sparks are coming from the transistor test socket.
:-DD
No holidays for you and your surge tester. >:D
What meter to fun first in 2016? Would like to see that Keysight GDT protection in action
What meter to fun first in 2016? Would like to see that Keysight GDT protection in action
Maybe not the first meter, but it'd be nice to see a BM257 run at some point. You've run a lot of lower end Flukes and compared them to your BM869 as a comparison to Brymen meters, but it seems to me that a BM257 or similar would be a fairer comparison in terms of price range / size / etc.
Thanks for the videos. I've been watching them from the beginning and it will be interesting to see what survives in 2016.
I have a feeling the larger GDT devices will survive the test, but the other protective devices will certainly fail. The more common larger GDT devices will absorb enough energy to clamp a spike down to 1kV even if the spike is a direct lightning hit. The traces will vapourise, but the GDT will still be there unbroken in the carnage. Seen that in plenty of telecoms applications, where you find the green module blackened and burned, with nothing left of the incoming wiring, the IDC Krone socket, the PCB holding the GDT units or the earth wire, unless you used 10mm cable for it. About 10% chance the PBX after it has survived unscathed, they generally blow all the line cards, power supply and any extension card that ran into the incoming frame. The phones however typically will survive, unless they were in use when the lightning hit.
I just was thinking that instead of blowiing up a bunch of more meters, why not run a video on the protection devices that can be found inside. Run a PTC or two, some MOVs, gas discharge tubes, etc. This would give easy subjects to video, and some fun fireworks perhaps. It would also be much cheaper and easier to video. This would help illustrate the actual safety of the safety devices themselves.
no i dont have circuit in mind. its just an idea because the UNI-T PCB always come with unpopulated MOV. if say by putting in the MOV, and it can stand up to some more surge, it could be good news for some DIY-ers who are interested to mod it but do not know the result for a real surge.
There are a few things you should consider.....
There are many many different MOVs in the world. I would doubt they put it right across the inputs for example. So even if you knew the MFG and PN for the MOV, hooking it to the generator is not going to tell you much.
Even if you traced out that part of the circuit of the meter you are wanting to test, clearances would not be the same if I just threw something together. If your goal is to test a specific meter with some changes, I think to really know what is going to happen we would use the real meter.
Next is your statement about "...DIY-ers who are interested to mod it but do not know the result for a real surge."
First, let's talk "real surge". Let's just assume that the IEC standards represent a real surge. I have been involved with these tests from time to time. Believe me, if something goes wrong there it can be a real thrill. Even my little half cycle line simulator does not come close to the amount of energy we test to. And believe me, with all the comments people have talked about safety and how the meters have never been shown to be unsafe during my tests, the last thing you want is for someone who has no clue to modify their own meter and then think it would survive these tests or worse, somehow be safe. None of us want that. This is why there are real labs that run these tests.
Its fun to look at some of the mods people have done to their handheld meters. Some of those rat nests would light up on a real test and worse, after cutting holes in the case, may actually come apart. No thanks...
If the goal is to "harden" the meters front end, I tried to show how to make an attenuator for a meter. Once again, people started talking about safety, which was never the goal. It is a good way to protect the meters front end. That may be a better approach.
That said, believe me, I know what you are getting at and you are not the first person to ask me about this. My advice is just buy a better meter if you are concerned about it.
A little info on GDT and usage and turn on.:-+
http://www.citel.us/gas_discharge_tubes_overview.html (http://www.citel.us/gas_discharge_tubes_overview.html)
Littelfuse datasheet, they are probably the devices installed.
http://www.littelfuse.com/~/media/electronics/product_catalogs/littelfuse_gdt_catalog.pdf.pdf (http://www.littelfuse.com/~/media/electronics/product_catalogs/littelfuse_gdt_catalog.pdf.pdf)
they are rated to handle a pulse with a risetime of 1kV/us, so turn on is pretty fast. Failure is by going open circuit on the 2 terminal devices, though you do get safety ones that have a shorting bar that fails the device as a short circuit when it is ruptured.
Page 10 shows that it pretty much is turning on after around 300ns of the transient being applied, most of this probably due to lead inductance. They tend to stay on until the voltage drops below the holding voltage of around 140V, though they can easily clamp at over 1kV on a high energy pulse limiting the downstream side to that. Probably that is why they use 2 in series, so the voltage is clamped hard by the second stage to the breakover voltage of the second device.
PS: They're not 'recommendations'. It only measures one tiny aspect of a multimeter (resistance to sparks).
One?
The series resistance on the input does look like it will at least attenuate the pulse, though the survival of the resistor is not guaranteed, so it has a blast shield to keep the pieces more or less together. Then they cascade that again so it is likely it will safely absorb the pulse without blowing up, though the chances of it surviving are not that good it will at least absorb the test pulse. Low capacitance is a major advantage over a MOV, and the residual capacitance will likely help as well.
PS: They're not 'recommendations'. It only measures one tiny aspect of a multimeter (resistance to sparks).
One?
OK, more than one... :-[
I see an opening and excuse to post these pictures, no teardown was required as it seemed to be an incorporated feature..... :palm:Nice! I bet where the leads solder in would jump. Maybe if we were lucky, it would go from the red trace to the neon bulb first, then to the black for some added excitement. :-DD Then the leads look like they would light up.
So stay tuned.
This video shows a glass type gas discharge tube at low speed. Then I setup the counter at 1KHz and recorded at 240 and 960 fps. Looks like it can almost keep up at 960 as expected. Picture looks pretty poor. Guessing it's an operator problem...
This video shows a glass type gas discharge tube at low speed. Then I setup the counter at 1KHz and recorded at 240 and 960 fps. Looks like it can almost keep up at 960 as expected. Picture looks pretty poor. Guessing it's an operator problem...
The picture quality issue might be insufficient light. You generally need a lot more light at faster frame rates. I am by no means knowledgeable in that area but that's what it looked like to me.
Strange UNI-T ad where they go after Fluke.
https://www.youtube.com/watch?v=7fFjiLU5bF0 (https://www.youtube.com/watch?v=7fFjiLU5bF0)
I thought the continuity test would be the failure point but it's the only thing that survived. :-//
Quite a surprising amount of components inside it for such limited/low-accuracy functionality. :popcorn:
Hi Joe,
Your videos and this thread have been extremely helpful in my decision making about buying a budget multi-purpose multimeter, so thank you very much for the work you put in. I've posted my own thread concerning a couple models I've narrowed it down to, based in large part on your information. My question here has to do with your spreadsheet attached to this thread. Is there a way to annotate or color-code the headings so that I know the CAT rating each test applies to? Meaning, if one of the tests was "3.0KV 2 ohm", which CAT protection level would that fall under? I can look at the spreadsheet now and see where certain models failed, but I can't tell if the failure was before or after their supposed CAT rating (unless I'm missing something, which is totally possible, and in that case I apologize).
I'm specifically interested in the two Amprobe models and the Greenlee model you tested. The AM-510 and AM-530 are both supposed to be CAT III and the DM-20 was labeled a CAT II.
Thanks in advance!
- Eric
That was quick. :box:
That was quick. :box:
:-//
I have not yet ran any of the surge transients yet and am hoping to get to it this weekend.The weekend is here. Can I interest you in a slightly used Keysight meter?
If the meters do what you want, I see no reason not to get them just because of the results from this test.
It's too dry here to own a 61D or E. Would hate to have a meter fail because I walked across the carpet without my wrist strap on and touch the leads.
It's too dry here to own a 61D or E. Would hate to have a meter fail because I walked across the carpet without my wrist strap on and touch the leads.
In that case you leave the 61E on your bench (which must be grounded or you wouldn't be able to do anything) and you only carry the Fluke 101 around the house. :-)
The images don't seem to work... :-[
Two new meters are on order. Maybe in a week or so I'll have something to show....
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=199811;image)
:palm:
What meter is that?
Two new meters are on order. Maybe in a week or so I'll have something to show....
A blue one...? :popcorn:
Spreadsheet has been updated. The blue meter is next.:scared:
Great review on the VC99, Joe! Waiting for the smurf meter... ;)
Either the Hioki, the Davymen or a Itinlu (http://www.amazon.com/dp/B018IJBQPM/ref=sxr_pa_click_within_right_aps_sr_pg1_1?psc=1) DMM should be an interesting review.Great review on the VC99, Joe! Waiting for the smurf meter... ;)
Thanks. Hopefully making more of a review, showing more how the meters are built and looking at the current inputs will be helpful to a few people.
Just to be clear, the smurf meter is not the EEVBLOG rebranded Brymen. A few people have asked about running a Hioki. I am interested in it because it uses gas discharge tubes as part of its input protection like the Keysight meter.
The GDTs have their place for sure. I think they would work very well in a meter if designed correctly but looking at how the Keysight had no other clamp, I knew it was not going to fair well.
I don't think you can really say it was not designed correctly.
I saw where Martin?? did a review and talked about running a test like this using various parts. Apparently he never got around to it or decided it was beyond his skill/comfort level. It would have been interesting to see EEVBLOG put out a video like this as part of how the meter protection works. Both of these guys could do a much better job than I have. It's just hard to draw any conclusion from these tests. My only goal was to show the difference in clamping speeds.I too always wanted to do an evaluation with GDTs and equivalent protection devices (I did one on varistors). The main issues are the controlled high voltage generator and the companion probe - so yes, so far you are the best equipped of all of us.
Davymen? Never heard of it. Looked that the Itinlu, it's CAT II like the VICI and unfused. Send a link for the other one and I will have a look at it.Sorry, I thought I had edited the "Davymen" out as soon as I had realized it was an extremely lame attempt to brand Dave's Brymen. This should have never surfaced.
I saw where Martin?? did a review and talked about running a test like this using various parts. Apparently he never got around to it or decided it was beyond his skill/comfort level. It would have been interesting to see EEVBLOG put out a video like this as part of how the meter protection works. Both of these guys could do a much better job than I have. It's just hard to draw any conclusion from these tests. My only goal was to show the difference in clamping speeds.I too always wanted to do an evaluation with GDTs and equivalent protection devices (I did one on varistors). The main issues are the controlled high voltage generator and the companion probe - so yes, so far you are the best equipped of all of us.
Davymen? Never heard of it. Looked that the Itinlu, it's CAT II like the VICI and unfused. Send a link for the other one and I will have a look at it.Sorry, I thought I had edited the "Davymen" out as soon as I had realized it was an extremely lame attempt to brand Dave's Brymen. This should have never surfaced.
@joeqsmith
are you going to test the Digitek DT-2843R too?
I don't think you can really say it was not designed correctly.
You may not think so but I stand by what I wrote.
I have no idea if any of the meters I have looked at would fail in a safe manner or not if tested to the IEC standards. These tests are about the electrical robustness of the meters. If you want to know if a meter is safe or not, have it tested by an accredited lab.
Do you feel the GDTs, MOVs, PTCs and secondary clamps are all there for safety alone?
I don't think you can really say it was not designed correctly. The design meets the relevant safety requirements as intended, failed in a safe manner and although non-functional it presented no safety risk in that failed condition.
It's OK and I understand you are only testing robustness, but that is irrelevant to the point made.
You are using your robustness criteria and passing a judgment on their design as being incorrect.I have not edited my original post and stand by it.
yes, there is a MOV, a picture of mine, sory for the bad quality
Measure down to 10A...? :-//
tuff meter, huh? :-+
tuff meter, huh? :-+
If it had just a small amount more plastic in that guard I would not be surprised if I could not damage it.
I have updated the spreadsheet for those interested.
The Hioki DT4252 part 2.
https://www.youtube.com/watch?v=Acqktm1fgHo (https://www.youtube.com/watch?v=Acqktm1fgHo)
However, the point of the protective devices is to protect the user first, not the DMM, for the specific CAT rating of the meter.
From the slow motion, where the creepages are too close, added areas of arcing occur. If all the arcing is stopped by the plastic spacer it would be best to reshoot the video showing no added arcing occurs.
It would be better to use both the MOV and GDT at the inputs or MOV alone. The GDT acts to prolong the life of the MOVs particularly in high energy overvoltage.
Recall, this is a test impulse. The real world worse case is that the impulse rides atop high energy AC, such as line voltage, and if the arcing occurs, it provides the pathway for an arc blast.
In this screen grab, one arc extended around the plastic shield from V+ terminal. Another extends from the center GND terminal from one of end of the fuse and from the fuse end to the ground plane. You can also see the GDT glowing.
The meter surviving the arc is a good thing, but that could be because so much energy is shunted across the inputs nothing appears to the more high impedance DMM circuitry.
However, the point of the protective devices is to protect the user first, not the DMM, for the specific CAT rating of the meter.
Well, that's a bit of a flaw in this entire test series. It's like doing crash tests with cars, and then concluding that the car that deformed the least must be the best one, without considering what would have happened to the occupants.
Guessing it is a BZ series TVS from Littlefuse. Very fast...
You pointed out how it arcs without the fuse on the right. If I rerun the meter, would you like the fuse in place (which should prevent that arc)?
However, the point of the protective devices is to protect the user first, not the DMM, for the specific CAT rating of the meter.
nice meter :-+
nice meter :-+
I don't like how the Hioki has an error when there is a large offset in an AC signal. Not a fan of the display or back light on it.
I was looking at the Digitek DT-2843R you asked about. 5ky had sent me a TekPower TP2844R. The circuit boards for the two meters are very similar. There is a placeholder for the MOV on the TekPower but it was not populated. The Digitek PCB is marked K10062843R, the TekPower is K10052844R. It may do better with the MOV installed across the inputs with my tests but it seems like a bad idea.
nice meter :-+
I don't like how the Hioki has an error when there is a large offset in an AC signal. Not a fan of the display or back light on it.
I was looking at the Digitek DT-2843R you asked about. 5ky had sent me a TekPower TP2844R. The circuit boards for the two meters are very similar. There is a placeholder for the MOV on the TekPower but it was not populated. The Digitek PCB is marked K10062843R, the TekPower is K10052844R. It may do better with the MOV installed across the inputs with my tests but it seems like a bad idea.
thank you for taking a look into it, I saw your video testing it, and from that other guy too, I just wanted to know more clearly how it would do with some harder testing, and yeah better be careful.
and about the hioki, I liked it, it's a very robust meter, that can handle some bad stuff very well, I would buy one without doubt if I could, did a search just for curiosity, but they don't sell them here in brazil, I found a rebranded brymen, but the price is ridiculous, I think it's the same model that Dave is selling, maybe in the future I get something better if I can.
you are the one who likes the firecrackers :-DD , I'm curious how the pocket meters will do, or how many will just pop, and thanks for taking the time to test with the MOV :-+
@ Joesmith
here is a teardown of my oldie, Motech MIC 2200 A, the pics aren't great quality, but I think you can have an idea, just tought you might be interested, ok? it probably wouldn't survive your tests lol
the only reference to the brand, but it's not the same meter, BKprecision got the multimeter part from Motech
I was about to start a thread about the UT-171B vs the Brymen 869S so I am glad I saw your posts on the UT-181A. I had fallen in love with the 181's huge easy-to-read screen but when I found out about the 2 update/sec rate I was so disappointed. Is the update rate really that bad for such a modern meter?
The 171B seems to be around 5/sec which is why I started looking at that meter as an alternative, but the niggly feeling that there is no such thing as a "high end UNI-T" remains...
@ Joesmith
here is a teardown of my oldie, Motech MIC 2200 A, the pics aren't great quality, but I think you can have an idea, just tought you might be interested, ok? it probably wouldn't survive your tests lol
the only reference to the brand, but it's not the same meter, BKprecision got the multimeter part from Motech
Thanks! I like looking at old equipment and how it was built. It's too bad that the LCD is cracked.
I saw an old 80's digital hand held for sale local but they wanted about $40 for it with unknown condition. Had the side slide switches.
it's not cracked, probably the seal failed, I tryed to seal it again with some vitral warnish, it's probably a manufacturing problem, never fell or anything like that, it works just fine, I don't have any precision reference, but I did compare it to the Digitek and it hasn't drifted to much, almost spot on
However, the point of the protective devices is to protect the user first, not the DMM, for the specific CAT rating of the meter.
I would guess that most of the safety in hand held meters comes from the mechanics. Things like spacing, wall thickness, double walled, etc. Things like the GDTs, MOVs, secondary clamps, PTCs are there to protect the meter so it does not need to be replaced or repaired. Maybe have a look at patents 5396168, 5606481, 5920188
I get feedback on some of my meter videos that talk about the testing not being real world and how meters would never see these sort of conditions. Recently, I had an opportunity to pull apart a power supply that had been hit with a real line transient. So to be clear, not to the IEC or any other standard. I then wondered what would happen if I ran the same power supply on my home made generators.
https://www.youtube.com/watch?v=a2NVLzWV3_Q (https://www.youtube.com/watch?v=a2NVLzWV3_Q)
I don't think anyone on the net has demonstrated just what an impulse would do and compare it against other DMMs, than this series.
I get feedback on some of my meter videos that talk about the testing not being real world and how meters would never see these sort of conditions. Recently, I had an opportunity to pull apart a power supply that had been hit with a real line transient.
it's not cracked, probably the seal failed, I tryed to seal it again with some vitral warnish, it's probably a manufacturing problem, never fell or anything like that, it works just fine, I don't have any precision reference, but I did compare it to the Digitek and it hasn't drifted to much, almost spot on
That's great research, Joe. The Fluke patent is particularly interesting because that is now widely used by others, the plastic shields to supplement the creepage and clearances. As for the RS patents, in the early days of DMMs, input protection varied from maker to maker, but the prime focus was avoiding damage due to incorrect settings such as measuring voltages on ohms range. There was not much talk about impulses.
Once the IEC model for impulses on line voltage was agreed on, by 1992? CAT ratings were created, with a goal of user safety. I think only Fluke continues to state their meters survive the CAT rating impulse while the IEC criteria don't specify the device be functional after a successful test.
Today, I don't think any DMM can survive the required maximum impulse for its CAT rating without externally added impulse protective devices. However, your video series shows some DMMs can be designed to not only pass the CAT rating but also survive the rated impulses.
IIRC, some of your videos also show cheaper meters failing short of their CAT rating, while better brand meters being more consistent.
I think Joe is doing everyone a great service, not only does he have the skills to play with kV, he gives a superb post mortem, repairs the meter quickly [if possible?], then subject it to more impulses. Plus, more kudos for buying these meters himself to avoid patron bias, like a one man Consumer Report.
I don't think anyone on the net has demonstrated just what an impulse would do and compare it against other DMMs, than this series.
...
In Fluke promo video, they show the 87V failing at 17kV, but making it past 15kV [ but they do not show a full functional test between and the test is only done on the V scale.]
Joe I think you clearly show how to remediate this meter to make it a true CAT III, and thanks for ID the other protective devices. The Hioki is built very well, I just can't figure why they didn't go just a tiny bit more to give it the kind of impulse hardening you show can be done, fairly cheaply and easily too.
The office where my missus works recently had some sort of power surge. It left their telephone switching board looking a bit like the PCB in your video.
yes I intend to keep the oldie( it was a gift from somebody very close), but here in brazil it's probably impossible to find a replacement for this LCD, now they started to sell rebranded Brymens here, but they prices are ridiculous, I probably could get a fluke cheaper,but now I can't afford jack...I hope in the near future I'll get at least one real good meter, but...
I'll take a look at my stuff, to see if I can put something togheter
and your videos really do a good service, they are a good reference for people, and thanks to that guy who donated the meters for to testing, a real nice gesture
yes I intend to keep the oldie( it was a gift from somebody very close), but here in brazil it's probably impossible to find a replacement for this LCD, now they started to sell rebranded Brymens here, but they prices are ridiculous, I probably could get a fluke cheaper,but now I can't afford jack...I hope in the near future I'll get at least one real good meter, but...
I'll take a look at my stuff, to see if I can put something togheter
and your videos really do a good service, they are a good reference for people, and thanks to that guy who donated the meters for to testing, a real nice gesture
Wow, the Flukes are less expensive than Brymen! That's a twist!
It was a real nice gesture when 5ky (TechnologyCatalyst on youtube) agreed to donate those meters. I doubt very much I would have continued to test meters had it not been for that. It also forced me to come up with a better way to test them and to start publishing the results. It was a big win for the few people who are following along.
Weekend is here and I have a UNI-T calling my name.....
Thanks and glad your enjoying them. We can't forget about 5KY's contributions as well! Big thanks for giving me the opportunity to see just how much a Fluke 107 can take!! :-DD
Heh, the end of that is rather anticlimatic. It'd be really disappointing if that's all it takes to kill that meter. I'm hoping and guessing that it's the soft power feature that's causing the issue there (why do manufacturers feel they have to add soft power on high end meters?)
Btw, one thing you mention in nearly every video is the term FWHH, but I don't understand what that means. Maybe you explained it already somewhere, but I missed it? If not, maybe you could show a scope trace of what it means exactly if you find the time.
:wtf: dead with one hit??? yeah that old saying is always right, when it looks too good... I'm really disapointed, I tought it would perform better tha that, but the video was excelent
The old Uni-T Achilles heel. :palm:Three of the five that failed this were UNI-T. This was a test I really thought was a waste of my time to even run as that starter is not much of a pulse.
are you going to try to find out what went wrong and fix it? just a question not a request
This was a test I really thought was a waste of my time to even run as that starter is not much of a pulse.
Just an observation: The non-contact UNI-T clamp has more input protection than most UNI-T multimeters.
Does that make sense to anybody? :-//
Here, with carpet, during the winter the air can become very dry and I get get some pretty good static going. If we use the human body as a means of measuring the energy (because that is very scientific), I will say I have had a lot more pain touching things with my finger from a normal discharge than I have with this starter. In the end, I really don't know. The one thing I do know is that the vast majority of meters handle this transient with no problems.This was a test I really thought was a waste of my time to even run as that starter is not much of a pulse.Do you think it's similar to the sort of sparks people can generate by walking on nylon carpet, etc?
Wow, that was a shocker and it didn't even get past a warm up.... :-BROKE :-+
Boot up times hardly count for much if shortly after you kick the bucket.... ::) :P
This was a test I really thought was a waste of my time to even run as that starter is not much of a pulse.
Do you think it's similar to the sort of sparks people can generate by walking on nylon carpet, etc?
I did write UNI-T a few days ago about the display update rate and was hoping that even though the meter is now damaged that we could at least open some sort of dialog. It is very rare when a company will respond to my emails but you never know.
Quite shockingly poor protection, know one would know without this thread. Uni-T can make good meters as its been the OEM for several Amprobe models, I have an older post on eevblog with copies of testing documents showing the OEM.
Joe, do you know the output voltage of your spark igniter? Its really not supposed to kill the meter unless the input protection components didn't work for various reasons: counterfeit, wrong spec used, PCB defect etc.,. The tear down you showed shows it should have worked. It would be great for you to trace it out and zoom into the protection areas.
I did write UNI-T a few days ago about the display update rate and was hoping that even though the meter is now damaged that we could at least open some sort of dialog. It is very rare when a company will respond to my emails but you never know.Did you send them a link to this video?
joeqsmith, that was an excellent video! Nowadays anyone can slap a powerful Cortex A processor to handle a beautiful GUI, but the appalling susceptibility to transients only shows UNI-T is blatantly lying on their CAT Ratings. :--Thanks. Glad you enjoyed it. I really have no idea if any of the meters I have looked at would be considered safe or not. Certainly, I have never thought of an ESD test as being safety related.
I would completely understand if they had marked this meter as a portable "lab meter" where you are not really required to have any ratings... Their webpage (http://www.uni-trend.com/en/product/2014_0711_586.html) does not mention any CAT ratings, but its manual (http://www.uni-trend.com/uploads/soft/wanyongbiao/UT181A--Manual-English.pdf) does.
I suspect they will eventually do the same releases as the UT-61: UT-181A, UT-181B, C, D... until it gets somewhere close to its alleged safety.
and end up with a $300+ brick...is kinda ouch!Agree. But maybe that grill starter test is just too harsh of an environment.
I thought someone would have ran these test and while searching, came across this:
http://www.bartek.com/Bartek/ESD.html (http://www.bartek.com/Bartek/ESD.html)
I thought someone would have ran these test and while searching, came across this:
http://www.bartek.com/Bartek/ESD.html (http://www.bartek.com/Bartek/ESD.html)
That Uni-T is pathetic, your tests has made me much less likely to recommend Uni-T.
The gun looks like a modified vinyl anti-static gun.
We still use them in the lab for getting powders in the tube in hyper dry environments.
I thought someone would have ran these test and while searching, came across this:
http://www.bartek.com/Bartek/ESD.html (http://www.bartek.com/Bartek/ESD.html)
That Uni-T is pathetic, your tests has made me much less likely to recommend Uni-T.
The gun looks like a modified vinyl anti-static gun.
yeah, I have an old eletronics magazine that shows one of these for vinyl, if I find it I'll post a pic
That Uni-T is pathetic, your tests has made me much less likely to recommend Uni-T.
The gun looks like a modified vinyl anti-static gun.
That Uni-T is pathetic, your tests has made me much less likely to recommend Uni-T.
The gun looks like a modified vinyl anti-static gun.
Vinyl? Post a little more info.
Quite shockingly poor protection, know one would know without this thread. Uni-T can make good meters as its been the OEM for several Amprobe models, I have an older post on eevblog with copies of testing documents showing the OEM.
Joe, do you know the output voltage of your spark igniter? Its really not supposed to kill the meter unless the input protection components didn't work for various reasons: counterfeit, wrong spec used, PCB defect etc.,. The tear down you showed shows it should have worked. It would be great for you to trace it out and zoom into the protection areas.
When you look at how many meters survived this with no problems, they certainly have a few examples they could have copied from.
I posted my homemade targets a page back and had looked for the data I took but looks like I did not save anything.
Keep in mind, I am not sure that a hand held meter is even required to pass any sort of ESD event. What I can tell you is looking at a manual from Fluke and Hioki, they both call out EN61326, which references 61000-4-2. My guess is that the meters would fall under Annex A, criteria B. Looking at the manual for the UNI-T, I do not see a reference to an EMC standard, only for the safety. The basic current wave shape for the -4-2 standard should be on-line.
found it! and got some info too, the pic isn't great but...
the voltage output should be from 15 to 20.000 volts
I think that's more stuff there, I need to dig deeper at my magazines, if I find some more usefull info I'll post it later
The CAT rating has nothing to do with being able to function after being hit with a high voltage. The CAT rating is for the safety of the user, not the meter.Lightages, you are right. Despite this, it does not inspire much confidence if the meter does not survive in an extremely low energy scenario...
Oh come on, after watching three UNI-T meters fail this test including their top of the line one, I have the highest confidence that this brand will continue to fail these tests! :-DDThe CAT rating has nothing to do with being able to function after being hit with a high voltage. The CAT rating is for the safety of the user, not the meter.Lightages, you are right. Despite this, it does not inspire much confidence if the meter does not survive in an extremely low energy scenario...
I am starting to suspect that even the Harbor freight stuff (http://www.harborfreight.com/7-function-multimeter-98025.html) would fare better than these Uni-T meters...
I am starting to suspect that even the Harbor freight stuff (http://www.harborfreight.com/7-function-multimeter-98025.html) would fare better than these Uni-T meters...
and you could throw it in the trash without any remorse, and a top end meter that can't take some stress, as Dave sayid before and he is absolutely right, what a waist of money...
I am starting to suspect that even the Harbor freight stuff (http://www.harborfreight.com/7-function-multimeter-98025.html) would fare better than these Uni-T meters...
I don't think I have ever tested the Harbor Freight meter with the grill starter. Does make you wonder.and you could throw it in the trash without any remorse, and a top end meter that can't take some stress, as Dave sayid before and he is absolutely right, what a waist of money...
I think I will pick another one (HF) up for the pocket meter testing. Cause you know that there is going to be some carnage during that test! Two of the meters are UNI-T. Did you know that you can always download that spreadsheet from the first post rather than hunting through the videos?
yes I know, but it's .xls format, I need to find a plugin or something like that for firefox to open it, most stuff on the net like manuals and other stuff is PDF format so I open it directly in firefox. and about hf meter, is this thing survives the test it would be hilarious, at least if it doesn't, won't be a big loss, I'm kinda curious if you can repair the uni t, it was looking good compared with the fluke, the menus and etc
I have uploaded the last data I collected that included the UT181A. I also converted the data to PDF.
I am starting to suspect that even the Harbor freight stuff (http://www.harborfreight.com/7-function-multimeter-98025.html) would fare better than these Uni-T meters...
I don't think I have ever tested the Harbor Freight meter with the grill starter. Does make you wonder.and you could throw it in the trash without any remorse, and a top end meter that can't take some stress, as Dave sayid before and he is absolutely right, what a waist of money...
I think I will pick another one (HF) up for the pocket meter testing. Cause you know that there is going to be some carnage during that test! Two of the meters are UNI-T. Did you know that you can always download that spreadsheet from the first post rather than hunting through the videos?
yes I know, but it's .xls format, I need to find a plugin or something like that for firefox to open it, most stuff on the net like manuals and other stuff is PDF format so I open it directly in firefox. and about hf meter, is this thing survives the test it would be hilarious, at least if it doesn't, won't be a big loss, I'm kinda curious if you can repair the uni t, it was looking good compared with the fluke, the menus and etc
The 181A is given a drink and bullet to bite down on.. The 210E knows from experience that this can't be good!
The 181A is given a drink and bullet to bite down on.. The 210E knows from experience that this can't be good!
any survivors? :-DD what's next?
when I saw the 181A with the bullet, I tought you would just trash it, I just asked because I tought that you really would targed practice on it
Thanks Joe, this was an excellent effort on your part and it made for a great video, it clearly shows that improvements for reliability can be made to some meters and perhaps some manufacturers who see this may take it on board.
I did like the way you utilised the hold button on the first meter before switching to the second to retain the measured value for comparison, I wish others would do the same thing when comparing meters so we don’t have to remember what the previous meter displayed, this was a nice touch.
To sum up……. :-+ :) ;)
That was interesting to watch, thank you for making the video. I'm a bit puzzled though by one thing: Obviously Uni-T put in some effort into making the meter robust to transients, so how could they miss the ESD susceptibility? Or rephrased, how would the meter survive transients, but not ESD events? Is this because of the (presumed, on my part) much smaller rise time of static discharges?
In any case, it feels like they're stepping up their game. If you look at what they've been doing so far, the next generation of meters in a couple of years will probably be hard to fault, but cost a third of what a Fluke costs. Which will hopefully make Fluke and others think about some strategic improvements as well. And your videos as well as those of your fellow videobloggers sure help with making issues more visible :)
Great job remediating the problem.
For other readers, a big difference between the tests is that static discharge waveforms are in nanoseconds while the impulse waveform are in microseconds. So the energies involved relative to human injury is mJ for static versus J for impulses, but to high impedance electronics, its still deadly. Why Uni-T didn't take it into account is puzzling given the effort to get ETL listed, typically the ETL consultant would have mentioned it.
Looks like a good sized transformer. I wonder if any handheld meter would survive a 1 minute hookup.
Looks like TME is selling the UT71D for $170 US. Not the cheapest handheld to kill this way.
Nice use of the current shunt on the Fluke 101. :popcorn:
Nice use of the current shunt on the Fluke 101. :popcorn:With the 4-20, I would think the risk would be fairly low but you never know.
Nice use of the current shunt on the Fluke 101. :popcorn:With the 4-20, I would think the risk would be fairly low but you never know.
What's the risk? A burnt out resistor?
Working in an industrial environment and hooking up to anything with an unprotected device would have a risk. Assuming your working in the range of 24V or less would seem like a risk. With what I show, there is no blast shield, no fuse, the wires hang right out there for you to touch and the banana connectors are not what should be used. A clamp would be much safer choice and because you are not going in-line would make things go quicker.
Again, I think the risk would be fairly low but buying a meter that has all the protection built-in seems like a small price to pay if this is your job.
The last meter just won't die.Sub $20 meter....... :wtf: :o
You think Dave's meter has a chance of surviving at least half way through? Should at least meet the CAT ratings though.
That they all didn't fail at 1.5kV was astounding. :scared:
Interesting that some of them actually blew the case open when they failed even though it's still in the "low energy" range.
I wouldn't like to have one in my hand when that happens.
(More proof that the magnetic hanger supplied with high-end meters is really a safety feature, not just a convenience)
Any chance of some hi-res pictures of what's left of the VC921 PCB?
That model has been discussed here before, but the PCB looks to have been redesigned:
https://www.eevblog.com/forum/testgear/victor-vc921-pocket-multimeter-worth-a-bash/ (https://www.eevblog.com/forum/testgear/victor-vc921-pocket-multimeter-worth-a-bash/)
How would this thing below go ?, I had a play with one of these recently only for a few minutes and for a couple of awkward applications I can see a spot for one in my toolbox, they are around thirty odd bucks I think and sold under many names including Mastech.
Great video Joe, thanks again. Given how less robust these DMMs are designed it becomes like a teaching video of where and how they fail, and mitigating one failure can just expose another.
After testing so many meters, I have a fair number of test leads. The meters get recycled but I hung onto the leads thinking I may do something with them.
One way to test them would be to put some DC current through them. The HF meter for example can measure up to 10A. I would think the leads could handle at least 12.
Another may be a pull test on the connections.
Maybe I apply that half cycle transient through them without a fuse.
Hi Joe, IIRC the IEC safety requires a sustained 10-15kV for test leads for working voltages of 1kV with potential breakdown test points in various locations and mechanical stress configurations.
Here's the full suite as applied to Amprobe test leads.
Finished with the current source test setup. I ran some tests with it using a few different probes and the differences are pretty dramatic. I already melted one lead (in the range it was rated for!).Tease!
Finished with the current source test setup. I ran some tests with it using a few different probes and the differences are pretty dramatic. I already melted one lead (in the range it was rated for!).
I have no idea if any of these probes are certified. They have a CE mark on them and most will state CAT ...
Looks like a nice day outside. I have my wireless router and my tablet PC ready.... The indoor testing is first. Here is the line up. All virgin except I plan to use one of my own set of probes that I normally use as a sort of base line.
:-DD I am just trying to get a feel for how it is all going to work. Say you have two meters. Both have a 10A current input. You would sort of expect the leads that were supplied with the meter to handle 10A forever.
Any results would certainly be helpful! FWIW all Fluke and Amprobe branded probes are NRTL.
A lot of those meters say things like "10A for 10 seconds maximum" in the fine print.
I kept 5KY's UT61E for a mechanical sample because it is such a popular meter. I could jumper out the fuse on this meter and run it. I can see someone doing something like this in real life.
What would a person use? Maybe a bolt? Too hard to find something that fits. Wire!!! So RG58 braid packed in there.
What would a person use? Maybe a bolt? Too hard to find something that fits. Wire!!! So RG58 braid packed in there.
I'm sure the UNI-T clan is going to be all up in arms. I can hear it all now. "Only and idiot would do something like this!!" :-DD :-DD Maybe the professional trolls will even chime in on the Youtube comments....
Time to head outside...
Not the fry up that I would have expected with any of the cheap leads and that most withstood up to 20A or more is staggering.
Joe, did you do any probe lead length comparison that could have affected Vdrop results ?
Thanks Joe, great work as always. :-+
That there's a range of 13" over the lead lengths is surprising :o so is there any sense in recalculating the results to reflect the lower R/foot leads. :-//
Those leads catching on fire like that should be completely unacceptable. Smoking and melting is ok, catching on fire is not.
Also, I have a feeling the FLuke leads in china, just like the meters, are made by Uni-T (maybe to slightly better specs than their own stuff).
Those leads catching on fire like that should be completely unacceptable. Smoking and melting is ok, catching on fire is not.
This situation is almost impossible in real life. Something else would fail first.
Those leads catching on fire like that should be completely unacceptable. Smoking and melting is ok, catching on fire is not.
Fluke provides protection through fusing in its digital multimeters (DMMs), but fused probes provide protection to those who have multimeters that lack the protection designed into Fluke models.
In addition to meeting entity and organizational requirements for fused test probes, you might also want fused probes because you’re interested in additional levels of protection.
Voltage readings with a blown fuse are approximate and vary with the meter impedance.
Thanks to the EU, for the price of a good fused meter you can buy these instead. 10A with an interrupt rating of 20KA. Even with the fuse blown they still work, although, it's a scaled reading. Someone obviously though this was a good idea.
Those leads catching on fire like that should be completely unacceptable. Smoking and melting is ok, catching on fire is not.Pedro, IIRC these probes are required to use flame retardant plastic, not flame resistant.
Also, I have a feeling the FLuke leads in china, just like the meters, are made by Uni-T (maybe to slightly better specs than their own stuff).
Finally, a meter that is not only designed to survive a 6KV transient but measure it too! 8)
Joe, the link should have been:
https://www.eevblog.com/forum/testgear/multimeter-help/ (https://www.eevblog.com/forum/testgear/multimeter-help/)
The 194 you mentioned seems to be very interesting, but the avocado green is really flashy! I wonder if it glows in the dark... :-DD
Overall the specs are good. I was surprised to see a 50mVDC range, but then the ±10 digits brought me back to reality - it may be suitable mostly for trend analysis (similarly to the 500k count on my BM857). I like how they clearly specify the bandwidth in the AC specs. However, no mention of bargraph update rate (the text actually seems to indicate it is 4Hz).
BTW, nice Hioki meter!
If I understood correctly what you said, the 194I has inductance measurements? That is impressive. The 50mV scale improvement also turns it into a more interesting range. I guess they are able to reach these levels due to a reduced bandwidth.Yes the 194II has an inductance measurement where the 194 did not.
In some of the other videos, I had used an RF generator and small antenna to see how sensitive the meters were to RF. I forgot to do this with the TPI and will include it with part 2.
TPI is checking into the scrambled data displayed after logging. I think I will wait until next week before I start working on part 2 and give them a chance to find the problem.
Strange that there is not more information about this brand out there.
The ONLY thing I know about this brand is that they supposedly make meters for Snap-On, like the EDM604AC which should look very familiar to you, and also Bluepoint (Snap-On value brand). I guess now though we know that they are made by Summit. Looking at their lineup they have several that are very clearly Summit meters.
Did you damage the DMM with just 270V in the ohms range? This is quite poor result for a CAT IV 600V DMM.
Joe, I feel bad for you for frying a $250+ meter (almost) beyond repair. Just like unfused current inputs, an unprotected ohms input is below acceptable in 2016... :(
But then again, the UT61E remains very popular, so there are people that really don't care about this stuff.
But then again, the UT61E remains very popular, so there are people that really don't care about this stuff.Plus: The web is full of pictures&videos of people using UT61Es. A lot of people will assume it's a good meter based on that. Popularity breeds popularity.
Sales staff have to deal with exactly that kind of behaviour fairly often (except usually it's meant in earnest.) I doubt they'd appreciate the humor.
Put them back together, with the leads, and return to Harbour freight. Say you took them out of the pack, and wanted to measure a single AA cell voltage, and this is what happened. Try to keep a straight face as they take the slightly abused part kit out of the package and look at it.
Who knows, if you video using the cellphone camera ( and you are in a single party state so do not need consent) another viral video will result.
Nice study, too bad you couldn't test the UT61E in this with its known temp drift issues.
Joe, good unfused Amp testing (sorry, I am trying to catch up on my video queue)
One detail about the temp testing: I wonder if there was thermal influence in the lead contacts? I am thinking about the interface between different metals, cable resistivity, etc... Despite the voltmeters have a very high input impedance, the differences are in the 10-3 to 10-4 range...
I wonder why the Fluke 87V failed at tests when exposed to a 1500V pulse. Isn't it UL listed? Was there already a faulty MOV or PTC?
..
There seems to be good protection on the PCB of Fluke 87V. I am not sure if Fluke 101 is better designed.
I have been curious about the GS version of the UT61E since I first read about it.GS version?
GS version ?GS certified. This version is sold in the European markets. As mentiined it has beefed up input protection compared to the Chinese version.
Anyone interested in a slightly used UT61E? Appears to have little wear. Includes some spare parts, original box and manual.
A little pre warning. There will be two parts. The first video runs about an hour. I spent a fair amount of time explaining the what/whys and ran several tests to prove out my results. Like any problem, there are going to be many solutions. I touched on only a few.
It's not a good video for the person who just wants some circuit they can copy but I do show everything that is going on including the mods.
So if you're one of these people who have added MOVs or GDTs to your UT61E or if you have told people this is a smart thing to do, these videos are just for you.
Hi Joe
Thanks for the video.
Great work, appreciate the effort you put into this. :-+
Yes, good work Joe. I am glad that you put in those disclaimers about this making any difference for safety. All the modifications surely made a difference in the survival of the meter but people really still need to understand that this does not make the meter any more suitable for high energy power work. Thanks for the time and money you put into the videos.
Thanks Joeqsmith :-+
Guess just fiting the MOVs does not do much :(
Always enjoy your videos :-+
Yes, good work Joe. I am glad that you put in those disclaimers about this making any difference for safety. All the modifications surely made a difference in the survival of the meter but people really still need to understand that this does not make the meter any more suitable for high energy power work. Thanks for the time and money you put into the videos.
I have never made any claims about safety, only robustness. I watched several videos on the UT61E before I made these last two. This included yours.
https://youtu.be/hhBbvIf3E0s?t=84
I didn't understand most of your comments about it somehow relating to the IEC standards. The UT513 is an insulation tester and supplies a DC voltage. My guess is had spark gaps been installed the meter would not have survived. I am not even sure if you had MOVs in it like the GS meter that it would make it.
What I don't like about your video is that it leaves people with the idea that the meters can survive 5KV. If you measured the voltage across the meter when you ran the test, my guess is you had no where near the 5KV claimed. If you look at the manual for the UT513, the short circuit current is less than 2mA. The PTC would not even flinch at this. Novices watching that video may think, hey 5KV, let me hook my Brymen to a 5KV 10KW supply.
Van Halen Eruption !! :-DD :-DD
;D
Van Halen Eruption !! :-DD :-DD
;D
:-DD I could toss out that could do this!
How much extra do you think it would cost Uni-T to build the new super meter?
(compared to the existing one)
How much extra do you think it would cost Uni-T to build the new super meter?
(compared to the existing one)
I'm have no idea what their engineering costs are, cost to tool a new board, line setup, changing test fixtures, changing procedures, buying parts..... Are they subsidized, what sort of pricing do they get .... Who knows. It's not as simple as saying they just sprinkle a few parts in. I would say your guess is as good as mine.
I'm not sure what the super meter would even be.
How much extra do you think it would cost Uni-T to build the new super meter?
(compared to the existing one)
I'm have no idea what their engineering costs are, cost to tool a new board, line setup, changing test fixtures, changing procedures, buying parts..... Are they subsidized, what sort of pricing do they get .... Who knows. It's not as simple as saying they just sprinkle a few parts in. I would say your guess is as good as mine.
We already know they make different versions of their meters.I'm not sure what the super meter would even be.
I mean the UT61E but with decent protection like the one you built. It has a decent chipset in it, it's a shame you can zap it with simple ESD.
It's a beaut little meter, one of the safest and well built meters in a small form factor.
With the CAT IV rating (exceptional for this size of meter), you can feel confident and safe that you can use this meter on any high energy mains rated equipment in almost any scenario.
You were wondering how they damp the meter movement from damaging itself, which is done using the aluminium former that the movement coil is wound on. This forms a shorted loop in the meter magnetic field, and thus provides a frictionless damping for the meter needle, damping fast acceleration by being both an eddy current damper in the magnetic field of the magnet to fast angular acceleration of the needle, and also being a shorted turn in the transformer formed from the coil and conductive frame so reducing the effect AC current has on the meter movement. However the pivot mountings are the weak point, dropping the meter often either breaks the pivot off of the coil as the drop of shellac holding the pin there breaks, or it bends the pin and adds a massive friction load with the bent pin, or simply moves the coil into contact with the frame, or out of the linear portion of the gap field making the response less linear than it was.
Nice review Joe.
This is the best review yet of the BM235, IMHO
I especially liked the reverse engineering of the input protection circuitry.
I also liked the comparisons with the other meters.
Thanks for the time and effort you put into your videos.
3DB ;D
Hi tautech, after Joe showed the modification that Brymen had apparently done to the case mating sleeve by removing material I pulled my meter back apart to check and inserted a sliver of aluminium foil which is around 10 microns in thickness over the top of L3 and then put the meter back together and cranked up the screws with the batteries out just in case, after re-inspection there was no evidence on the foil that the sleeve was making contact with L3 on my particular meter.
As you mentioned after a recent component issue in that area perhaps Brymen felt that the clearance was insufficient thus their modification. My meter was one of the first sold and the case mating sleeve is intact and not modified as Joe’s appears to be.
The EEVBLOG rebranded Brymen BM235.
I passed on the link for the video to Brymen. They said "As the poor installation of the input jack assemblies, I have informed our production to pay attention to it and improve it. Thanks for feeding back it to us. "
Just wanted to add thanks for all your work testing these meters Joe, really interesting to watch and learning a lot. Also great when looking to purchase some of these meters - especially the ESD type tests.
How much will the transient tests be wearing out the MOVs on these meters? It'd be interesting to see a test on a meter where the MOVs have worn out, and to see whether it changes the way the meter responds to transients.
Just on the subject of MOVs, I was recently called out by a client to check and rectify their existing security system which I had installed years earlier, the premises have been hit twice by direct lightning strikes destroying everything in the past but this time it appears to be a transient or surge up the phone line, Telstra did attend to the site and confirmed that they do have a line surge device on the line at the entry point but obviously something got past it. Here is a picture below of the damaged MOV measuring 26 ohms in situ, the other two appear ok and are each around 17 megohms.
The rest of the existing control panel was in good order and operational apart from failing to communicate so I simply replaced the main PCB with a new one as I didn’t want any further issues, the site was 500 kms round trip so I stayed for a few days and did some other maintenance around the place to make it a worth while journey, we also ate rabbit for a week.
MOV units degrade slowly.Not always the case.
The energy rating is not an indication of life, just how much they can take in a single shot.I don't think anyone made this claim. However if I put 10J into a 1J part or a 100J part, which do you think will survive longer? This is a question of derate and it's not something simple that could be answered. OP's question was "How much will the transient tests be wearing out the MOVs on these meters?" and my claim again is that I have yet to see a MOV fail during my testing. And I would go so far as to say if I took for example the EEVBLOG rebranded Brymen BM235 and attempted to run a test using my transient generator, I could not get MOVs to fail. The generator is just not capable and the PTC with the added resistor will really go a long way to prevent any sort of overheating in the MOV.
MOV units degrade slowly. The energy rating is not an indication of life, just how much they can take in a single shot. I have had them connected across the mains, and find that the large or small ones fail only after over 5 years of being abused, generally by going either low resistance, and thus blowing apart, or going dead short and either vaporising the one lead or turning into a skid mark on the mounting and a powder all over the inside of the equipment. Nice failure mode, generally takes out the fuse or breaker doing so.
Just on the subject of MOVs, I was recently called out by a client to check and rectify their existing security system which I had installed years earlier, the premises have been hit twice by direct lightning strikes destroying everything in the past but this time it appears to be a transient or surge up the phone line, Telstra did attend to the site and confirmed that they do have a line surge device on the line at the entry point but obviously something got past it. Here is a picture below of the damaged MOV measuring 26 ohms in situ, the other two appear ok and are each around 17 megohms.
The rest of the existing control panel was in good order and operational apart from failing to communicate so I simply replaced the main PCB with a new one as I didn’t want any further issues, the site was 500 kms round trip so I stayed for a few days and did some other maintenance around the place to make it a worth while journey, we also ate rabbit for a week.
Muttley just on the off chance, do you know what part number of MOV that is or do you know if a fuse is inline with it? It failed fairly gently so I'm presuming it has an in line fuse.
Tested a cheap meter on 7500V neon sign transformer. it survived .....for a while at least.Sean, I don't think you were going Photonic on your last video. To me you were simply using a non-orthodox method of reflow soldering to bring it back to life. Sure, a few cooked plastics here and there, but that happened even with Dave and his attempts to restore a TV in one of his episodes. :-DD
Then I went a little Photonic on it, and cooked it to death.
Battery expired in 2011, but still has life in it ( Yay Energiser) so put it in another cheap meter to eke the last life out of it ( Ok, I am out of 9V batteries, and only going to buy more later the month if I can get past the one shop with them pretty cheap).
Some time ago someone had offered to give me a pen type Mastech MS8211. Another person had asked about running one. Fairly inexpensive so I picked up a MS8211D. It's marked CAT III 600V, has some sort of current, a funky retractable tip and a strange logic sort of LED indicator. I have not had it apart yet but I wonder if it even uses a fuse as t looks like it can only read into the mAs.Joe, that was me, although mine is safer as it does not do current measurements. I have hi res pictures of its guts if you are interested (I am away from my computer now)
Hope to have some time in the next week or so to do something with it.
Sean, that's not a neon sign transformer... This is a neon sign transformer!! :-DD :-DD
https://youtu.be/RBkjr3b5hQo?t=379
Hi Joe, If you haven't already blown up the Mastech 8211 can you verify the maximum current it will cope with in regards to current draw, the manual states 200mA and I've been looking at these things for years but the two main concerns were current limitations and a lack of a backlight. :-+
Also Mastech's web site appears to have recently expired, shorted out, blown a fuse or something. :-BROKE :palm: :-DD
Haven't seen Joe about the place in a while, hope he is ok and the Mastech didn't get the better of him. :scared:
He is also about to hit 1000 subscribers so a big thank you and congratulations are probably in order, Thank you Joe and well done. :-+
Joe's Videos.
https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg/videos (https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg/videos)
I'm surprised you had all the features and were able to function test this unit with that wire and solder blob.
This is perhaps the uglyest multi-meter ever made but it has a bale, and what could be some decent test leads for a change.
jnicholas
Joe, that was a pretty cool mushroom in the high speed camera.
Despite it is stronger than your UNI-Ts, I can't help but imagine this is actually much more unsafe than a DMM on the table: the potential to burn the hand that holds the pen while this happens is pretty high.
Anyways, that was another excellent video! Thanks for doing this.
Well, my reason to assume the relative safety levels is based on the distance between the operator's body and the source of the explosion...
However, there's always a chance the dial of the meter on the table comes flying after the event and hits the operator in the head... :-DD
Joe, yes I am suggesting that.Well, my reason to assume the relative safety levels is based on the distance between the operator's body and the source of the explosion...
However, there's always a chance the dial of the meter on the table comes flying after the event and hits the operator in the head... :-DD
I'm not sure I follow. Are you suggesting because it is a pen meter that the operator would be holding it where a meter with leads, they would be holding the leads and not the meter and this means the pen is less safe? There could be some merit to that.
That knob flew about 8' across the room and hit the wall.I have experienced situations where flying remnants of average energy short circuits (mains) were targeted at me. Fortunately I used glasses at the time, which saved my eyes from any damage.
2017 is shaping up...
...one thing to watch out for is they have a tendency to go out of specification with even the slightest bounce on the bench because of the trimmers, easy fixed but still a pain.I think that adding a voltage reference (like done un the UT61E) may improve this... I'll take a look... if I find it's schema
Jaycar do offer a life time guarantee on the CEM meters which I have tested and they did come to the party on one I blew up, one thing to watch out for though is their current catalogue states a life time guarantee but the website states only 9999 months which equates to only 833.25 years, this could be a bit of a worry for immortals.:-DD :-DD :-DD
Jaycar - Digitech QM-1576I investigated a bit, disassembling Meterbox apps to look for names used in BT connetion; I planned to replace the internal RF module with a BT module, but trying an HM-10 (BLE), it is seen by apps only if named DM-9969 or DM-9989 that are those sold with a BLE module.
https://www.jaycar.com.au/ip67-true-rms-cat-iv-dmm-with-meterbox-smartphone-app/p/QM1576 (https://www.jaycar.com.au/ip67-true-rms-cat-iv-dmm-with-meterbox-smartphone-app/p/QM1576)
...one thing to watch out for is they have a tendency to go out of specification with even the slightest bounce on the bench because of the trimmers, easy fixed but still a pain.I think that adding a voltage reference (like done un the UT61E) may improve this... I'll take a look... if I find it's schema
Hi, The reviews and testing are excellent on joe's posts. Of all the meteres he shows in the rap up, the cheap Uniti e model looks to be the best bang for the buck. The tri state display on the Jaycar meter featured there and the water proof thing are nice but I guess I admit I don't get it. All these expensive meters would most likely would not be used in the field. In a work setting, I think something like a MF-47 analogue Simpson clone would make me more comfortable since it can measure up to 2.5K without blowing up. Most of these high end meters are going to see service in the on the bench, not during a rain storm hanging from a high tension pole.
Viewership has grown enough that today I have started working on an FAQ sheet for this testing. Hoping that will help out down the road. Just finished reading every YT comment. Once completed, feel free to add comments about common questions you feel I have not addressed.I guess that is the downside of being mildly popular... Perhaps they think they can get away with the fact the channel owner likes the traffic of the comments to increase its own popularity... I don't know - Youtube ratings and algorithms can be mysterious.
I have noticed people trying to use the channel to run ads now. I am not sure if reporting them (youtube allows it) really helps. So far, I just add them to the banned list. Strange as my account should be so far in the noise floor, seems using a more popular channel would make more sense.
Viewership has grown enough that today I have started working on an FAQ sheet for this testing. Hoping that will help out down the road. Just finished reading every YT comment. Once completed, feel free to add comments about common questions you feel I have not addressed.I guess that is the downside of being mildly popular... Perhaps they think they can get away with the fact the channel owner likes the traffic of the comments to increase its own popularity... I don't know - Youtube ratings and algorithms can be mysterious.
I have noticed people trying to use the channel to run ads now. I am not sure if reporting them (youtube allows it) really helps. So far, I just add them to the banned list. Strange as my account should be so far in the noise floor, seems using a more popular channel would make more sense.
Thanks. It's getting there but that 4ns edge is still too slow.Oopps, right, yeah I did read that the other day.
An IEC pulse has a rise time of less than 1 ns and dissipates most of its energy in the first 30 ns.
Joe, this progress is incredibly interesting. Are you getting these values under load or open circuit?
I have cooked some ideas to create spark gaps years ago but had to postpone my plans due to newborn babies along the way. Give it a few years and "I'll be back". :P
Keep up the amazing work man! I enjoyed a lot and your videos encouraged me to do some more research on ESD protection standards and tests. Thanks again.
It seems that I am having a hard time to understand and differentiate the safety vs robustness.Correct.
You managed to kill two fluke 87v's by puting a 1,500V pulse on their resistance measurement mode, however CAT IV 600V class, claims protection against 8,000V input surges an yes, at least the flukes failed safely.
Is it correct to conclude the CAT rating has nothing to do with the robustness and it is only a parameter of how a multimeter will fail in terms of safety?
Thanks for sharing the idea behind the tests. Well, that's shane there is no ratting for multimeter robustness and no one the industry (i'd like to exclude you) has properly tested and rated the handheld multimeters for robustness. In fact it's quite surprising!
Anyhow your tests are pretty unique and I believe if you document all your tests methodology and their results, perhaps it could lead to a new trend and attract knowen manufacturers. I hope.
It sounds to much to ask, can we have all your test results in a single sheet including torture pulse duration and voltages? I found an Excel sheet, in the first post, but it looks just a bit outdated and not well documented. Also how the various multimeter failed, they just failed with no explosion or something nasty happened too?
i wanted to try to understand the amount of energy released into a DUT under test, i ended up finding this https://www.onsemi.com/pub/Collateral/TND410-D.PDF (https://www.onsemi.com/pub/Collateral/TND410-D.PDF)
so in the IEC 61000-4-2 level 4 contact test, 8kV (it says 30A max, i thought there is no limit since it is suppose to be a surge?), i calculate that the amount of energy the DUT must absorbed if 100% discharged in 30ns = 28.8J, but that doesnt look right as there is a discharge curve and the actual amount of energy absorb look more like 50% (15J?) in 30ns and maybe 75% (22J?) in 60ns? is my guess somewhat in the right direction?
i assume if DUT survived the 30ns (or 60ns) 8kV discharge, the DUT wins (irregardless of how much energy was not absorbed but left over in the discharge capacitor) am i right?
and if based on human body model, the max current it states is 5.33A for 8kV, so much lower (energy going thru DUT = 5.1J ?).
with this, i assume that if i include in circuit design some kind of TVS with 50J of absorption capability, it is sure way to survive 99% of mishaps? yes?
and if based on human body model, the max current it states is 5.33A for 8kV, so much lower (energy going thru DUT = 5.1J ?).
with this, i assume that if i include in circuit design some kind of TVS with 50J of absorption capability, it is sure way to survive 99% of mishaps? yes?
Think mJ. My big generator puts out about 20 when cranked up.
The 87V on the chopping blocks. Interesting, they only look at the AC voltage mode and they do not appear to functional test the meter between steps. How do they know where it fails?
Yokogawa is the OEM manufacturer for Iwatsu
Joe, these are interesting clips. The fact they don't functionally test the meter after each "shock" is most probably related to the nature of these tests: they are supposed to contain and withstand arc flashes instead of "surviving".
I suspect the power strip in fumes is most probably due to the varistors.
I do prefer the results of your tests, as they measure the amount of headache a DMM can give you (as I only work with average power circuits).
Any chance you'd do a video on the Aneng AN8002 cheapie? I just keep thinking about seeing the little fella in the box, since somebody posted about the AN8001 a few months back. I say the 8002 just for the temp measurement
IMPRESSIVE video, as always! I happen to know how much time it takes to make videos. Getting all that testing done, and uploading in a day, is crazy fast. Then you actually repair the meter, geez, wish I had the knowledge and skills. You really LIT the CANDLE, several times.
Looks like a better meter for pocket use then my old Radio Shack "clamshell" meters. I would never test current with it anyways, but for quick voltage and continuity tests would seem handy for $30. Also, I don't have anything that small that can read Hz.
Thanks once again for taking all that time and effort to educate us with these tests. Don't know of anyone else willing to fry meters like you do!
Look forward to the ZT102 video.
It would be neat to see how it fares with more space/creapage distance.
Looking forward to the zt102.
The Woods DMMW3 pocket multimeter
The Woods DMMW3 pocket multimeter
Thank you for that in-depth testing!!!
The DMMW3 did better than I thought it would in your torture test. It's not a Fluke but I still like it.
The opening statement was:Yes, you are right. I glossed over these statements.
"It's important that test instruments and other electrical test tools are independently evaluated to make sure they can survive high voltage transients"
At 9:29Likewise. As I told you before, I prefer your tests as they give you a measure of the headache you will have with your equipment.
"With stout input protection our test instruments are built to survive" then they go on to show you some big boy toys.
Now I'm not suggesting that you need to actually test the instrument to know that it survived the test.... Of wait, that's exactly what I am suggesting! Of all the meters they sell, the one that failed at the lowest level during my tests is shown to be a superstar. :-DD
Of course, I wouldn't claim a meter passed ESD without ever testing it with the leads.
BTW, I just got a Fluke 27/FM and it is an incredible piece of gear that I suspect would survive a nuclear blast.
My go to "SAFE" meter is the EEVBlog BM235, but just to have a little home meter, I just bought the KASUNTEST ZT102, Amazon Prime, delivered for $20. I saw it on EBay for $16, but waiting 2-3 weeks from China with return hassles, made it silly to go that route. As you all know these are rebranded under other names. The EBay site was however informative, in that there are 3 models, one is a 2000 count, not many features, another one has NO temp option, in that switch position is just a 2nd "off" setting. The 3rd one is actually the ZT102, as it shows the temp option on the dial.
If I'm lucky enough to find a replacement fuse, I hope it's not 50% of the cost of the meter. :) Almost disposable at this price.
They both made it in.
Sharing the current input is never a good idea. I don't think any meter has survived where the designers have done this. Does anyone think this meter will survive the new ESD test?
How can Dave rightly call it the "121GW" unless it would survive a 1.21GW burst of electricity? :D
(Sent with Tapatalk, so apologies for the lackluster formatting)
Would be nice to test new Metrix line... http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html (http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html)
Nobody tested these yet?
Would be nice to test new Metrix line... http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html (http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html)
Nobody tested these yet?
I assume with the cost, it puts it out of the range of what most hobbyists would spend. They may buy a more common like Fluke or Gossen. Maybe TE will send one to Dave for a review.
Would be nice to test new Metrix line... http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html (http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html)
Nobody tested these yet?
I assume with the cost, it puts it out of the range of what most hobbyists would spend. They may buy a more common like Fluke or Gossen. Maybe TE will send one to Dave for a review.
Are you still planning to run the ESD tests on the ZT102?
Thanks!
Would be nice to test new Metrix line... http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html (http://www.chauvin-arnoux.com/en/produit/mtx-3291.html?liste=/en/produits/31/98/multimeters/trms-digital-multimeters.html)
Nobody tested these yet?
I assume with the cost, it puts it out of the range of what most hobbyists would spend. They may buy a more common like Fluke or Gossen. Maybe TE will send one to Dave for a review.
Are you still planning to run the ESD tests on the ZT102?
Thanks!
I sometimes with run the ESD before the AC line test. Normally, the meters are subjected to all of the tests until they fail. Since I started doing ESD testing, it looks like the only meter I did not test was the TPI 194II and that was because it was damaged during the AC line test. Interesting is someone posted a comment on YT about me not running that test on all the meters. Strange.
I finished running the ZT102. It did not perform like I was expecting. The video is going to have some extra bonus content in there as well. I should have it edited and uploaded soon.
I'm finished with editing and it's uploading while I post.
For me personally, I would take the BM235 over the ZT102/AN8002 for basic electrical work any day. Sure, it costs a little more but its also certified and is a lot more robust. If I needed a pocket meter for light electrical work, I would still go with the 101. I have no need for current or the TRMS feature and I am not at all a fan of having a shared current input. I would rather have the robustness the 101 offers.
For the bench, I'll stick with the Brymen BM869s for now. It's not as robust as some of the meters I have looked at but it has many features that I tend to use. I think my next pick would be that CEM DT9939 that Ruby sold for $120. That was a deal. Again, not a super robust meter, lots of drift with temperature but hard to beat that price with the features.
If the UNI-T UT181A had been more robust (electrically and mechanically) along with addressing the other concerns I have with it, it would be a very nice meter. As it comes from the factory, I'm not impressed with it but I feel it's better than the TPI 194II was. Now that was an over priced princess.
https://www.youtube.com/watch?v=HrcxnbkkhYg&feature=youtu.be (https://www.youtube.com/watch?v=HrcxnbkkhYg&feature=youtu.be)
I didn't think it would get as far as it did. I'm still interested in the Woods meter, just to have in my travel bag, but again was surprised the ZT102 did better overall in robust tests, perhaps the UL listing makes the Woods cost more?
Do you think the ZT102 would pass tests for a UL listing?
Thanks for testing the fuse as well, since I'll never use the ZT for current, good to know if I blow the fuse, it will still work in the other modes, can't thank you enough for revealing that! I'm tired of tracking down oddball replacement fuses.
I haven't seen that screw driver tester in 30 years, nice find.
I haven't seen that screw driver tester in 30 years, nice find.
Am I the only person still using one of these? :popcorn:
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=297085;image)
(just kidding, I'm not really... I remember using on in my youth though)
Not a bad little meter for low voltage hobby use.
(I think it needs uA though)
The Zotek ZT98/Aneng AN8004 has the microamp setting. Why not get one of each. :)
So it does... and cheaper, too!
But no capacitance or temperature - you can't win.
The KT6000 is TRMS, has temp, uA, a relative mode and the current inputs are not shared. They claim CAT IV 600V. Has 250V glass fuses and one vary small PTC and two transistors for the input protection. Lots of room inside.
Thanks for blowing up all these meters in the name of science, Joe. - Can't wait for the robustness testing on the KT6000 and still waiting for the ZT102 based meter to arrive via slow boat.
I was just kidding about doing a 20A test with it. I don't have the Lexan-protected safe box to do testing like you do...I'll probably keep this meter in a mA ranges max.
As for frequency at 500mV, 1V and 5V the best I could do stably was 10MHz. After that is sometimes would show the higher frequency briefly before going to all 0's - up to 20MHz then, nothing.
" I don't understand why this guy damages all multimeters?!?"
:-DD
:-DD" I don't understand why this guy damages all multimeters?!?"
:-DD
And .... we just love ya for doing it!
Ig Saturation 5 days ago
Excellent as always Joe. It blew close to where I thought it would, and the arc energy atomized the tracings with it. You could get another blast off that meter by doing the 10A input.
The manual has a CAUTION about auto range only in frequency mode. I wonder if they won't switch to the low range. Did you try both the mv and volts functions? Same results?
The spreadsheet and video for the KT6000 have been uploaded.
https://www.youtube.com/watch?v=4PjmFqzlfLc (https://www.youtube.com/watch?v=4PjmFqzlfLc)
FIRE & SMOKE reward when you get to the end of the video, NICE!
Some manual spec busting too.
If I'm interpreting this video and the ZT-102 video, correctly, while lacking some of the extra features, it seems the ZT-102 is overall more robust, correct?
These ZT/KT meter versions are rather afforable.
As a spare meter for electrical/car wirk it would either be one of these, or the more expensive am-510a.
Anyone tried the AM-500A?
That RS shunt is by far the largest I have seen in a handheld. I think this video is going to be a David vs Goliath story except David looses big time. :-DDIt looks like it will go this way.
Metrahit looks interesting...
The multimeters are protected against transient overvoltages of
up to 8 kV with wave-front durations of 1.2 ms and halftimes of
50 ?s in the voltage measuring range. If longer pulse durations are
expected, for example when conducting measurements at transformers
or motors, we recommend the use of our KS30 measuring
adapter. It provides protection against transient
overvoltages of up to 6 kV with wave-front durations of 10, and
halftimes of 1000 ?s.
Continuous load capacity is 1200 VRMS. Additional influence error
caused by the KS30 measuring adapter amounts to approximately
-2%.
The shunt testing is finished. Was going to test the shunt out of the 121GW but the foam would not conduct. And I thought it was the lowest burden meter out there.I'll be looking forward to it. I saw your post, and expected to see a video.
Video should be up in the today sometime.
In no way have I seen the insides of as many DMM's as Joe but in cheaper ones the shunts seem to be made of copper or brass. :--
Unless they're made of materials accepted for shunts like Constantan, no wonder there's some variability. ::)
Nice job, I enjoyed it.I use LabVIEW.
What was the software you were using?
Is that Centech yellow/green?
You bet it is. They could make the meter with 100A for a 20 seconds and if the shunt doesn't melt off the board, the leads would open.You should have filmed that.
I wonder how the probes included with the two Kasuntest meters would do. Better yet, I wonder what leads the 121GW will include.
Watched Dave's reviews of the Gossen power meter. :-- No way I would spend over $1000 on a meter with a tacked on resistor. Too bad, like some of the features. Review was not too great. Hardly turned the thing on.
Looked at various pictures of the internals of other Gossen products. Some look like they were made in the 90's.
Now looking at the lower end Extra. From the manual, they mention the KS30 for additional protection. Search their site, nothing. I would like to get the KS30 with it if I go this route but can't find anyone who carries it. Time to send them an email.QuoteThe multimeters are protected against transient overvoltages of
up to 8 kV with wave-front durations of 1.2 ms and halftimes of
50 ?s in the voltage measuring range. If longer pulse durations are
expected, for example when conducting measurements at transformers
or motors, we recommend the use of our KS30 measuring
adapter. It provides protection against transient
overvoltages of up to 6 kV with wave-front durations of 10, and
halftimes of 1000 ?s.
Continuous load capacity is 1200 VRMS. Additional influence error
caused by the KS30 measuring adapter amounts to approximately
-2%.
Daer Joe,
Thank you for your Email.
I just checked the article KS30 and it was discontinued several years ago.
This was a mistake in our manual and we will correct it asap.
If you require a quotation for M250A you can contact our US subsidiary:
Where did you get the manganin sheet from?
So, Joe, has anyone from UNI-T contacted you for a place on the engineering team?
Gossen provides a link to your video and I asked them if the meter was a proto or if the tacked down resistor was current production. I have not heard back. Did you ever find out?
I guess it is no more and they had a re-spin, this is mine, purchased about 18 months ago.
Full 20MP Hi-res image here (https://pryxta.bn1303.livefilestore.com/y4pC4au-4M7lCipjwHUZ0xNlrwsyaYTkGHzy9AIhraCci74StpSfHeNlIaUThPurALi1Bs7W16RHV_5ntNdZtVTUwWLhDhz2LxdOQfSCz5nQGc5aLHO_SEbQ3xeF3Nbv_1LNbQDoQXOoTU7KtqKXgHwkG0Y2e6VHj0QCcSpE8TMs4r7EL0IdB9aEEJheILiPPb9/P1000081.JPG)
(https://www.eevblog.com/forum/supporters-lounge/the-eevblog-multimeter-prototype/?action=dlattach;attach=308420;image)
Thanks for the picture. Looks good. After 18 months, any complaints with it? The only bad comment I have seen was on Dave's video where the person shorted the current inputs to the mains and damaged the meter.
I hardly ever use it. Being an Energy meter with simultaneous I and V, I bought it on the premise I'd be able to use it for measuring microcontroller power in and out of low power modes, but I'm afraid I've found it's useless for that. The relatively slow auto-ranging means the burden voltage changes so it has too much effect on the DUT. I really should've thought that through!
I am sure it's good for higher power simultaneous I and V.
The other thing is that there is a physical prevention of you having probes plugged in and/or moving the dial in certain modes with probes plugged in. I find it a bit of an irritation, a bit nanny state if you like, I'd rather it beeped at me instead.
The ground probe is stackable at the meter end which means it protrudes out. Now while a stackable probe is great in some circumstances, it means it won't fit into its purpose made case with it plugged in. I like to have a meter ready to go, probes connected, you can't do that with this meter if you use the carrying case.
I find using the meter itself a bit daunting, the UI isn't too obvious to me, I find I have to refer to the manual. This may also be down to lack of use though!
Despite being soft power on, the two AA cells are the same ones supplied with the meter 18+ months ago, so that works OK.
I would say that it does look the part when you get it out on the bench!
With apoogies, this is off topic.
I need to write Revlon a letter explaining I am a dissatisfied customer
SIBA branded fuses sold by UXCELL.
So I will give you that putting on of these counterfeits in say the UT61E's 500mA it would further improve the burden and I believe the diodes would handle the added current in that one case. However they are not using 4000 series diodes and I have those large TVSs in there now. I wouldn't attempt it on any meter I cared about without looking at the circuit to make sure it could handle it.
So I will give you that putting on of these counterfeits in say the UT61E's 500mA it would further improve the burden and I believe the diodes would handle the added current in that one case. However they are not using 4000 series diodes and I have those large TVSs in there now. I wouldn't attempt it on any meter I cared about without looking at the circuit to make sure it could handle it.
Agreed!
Call me Brandy Loyale, but I just ticked on " I think the Fluke 87V is really a good meter and want to see if a third one would be better"
TBH I don't think a 3rd or 30th would make a lot of difference, but would like to ask if Mr. Smith can recommend some simple improvements to the 87V so it can survive more of his advanced Lab testing >:D
and still work after a shuffling casual walk on carpet touch n zap test :horse:
An external protection box would be nice, so as not mess with the meter's insides and void warranties :-+
SIBA_drop showing 836.8mV of burden at 220.7mA. Pretty much what I showed in the last video for the 61E. Now look at the UXCELL_drop at the same current. 764.9mV of drop. So in the real world, we gained 72mV is all. Not much when you figure we are still over a half volt drop anyway.
On the contrary. Sounds like I must watch it to see what happened. :-/O
If only PhotonicInduction lived in Australia, then you two could take the piss out of some crap.
PhotonInduction is lame, any moron can break stuff, it's the lowest form of matter. The thing I like about Dave's videos is that for the most part they're informative and productive. There are already too many videos of knuckle draggers just breaking and blowing stuff up on youtube.
If you're looking for me to drool over it and put it on a pedestal to worship, don't watch.
I would like to know how often in the real world a surge or some other anomaly comes along and puts a technician at risk while in the process of troubleshooting a fault in a piece of (let's just say consumer) equipment.
My guess - not very damned often. Techs love the Fluke 87 and it's variants for a good reason. It's reliable and consistent, and safe. Period.
It is not necessary that it survive a gazillion volts at 1/2 height or whatever. In the EXTREMELY UNLIKELY event that it's ratings are exceeded in a given situation, the Fluke will "fail safe" and further - Fluke will fix it for FREE.
Meanwhile - you can rely on it's readings, accurate to a level exceeding spec by an order of magnitude even if the meter is over thirty years old.
What more can you ask from a multimeter for it's intended function?
I'm a Fluke fan-boy?
You bet - and for good reason.
While I'm not sure about the frequency of the surges, without a doubt they do happen. A local employer, a mining operation, had a electrician injured when he was measuring receptacle voltage (995V Phase to Phase), apparently the PT's onboard the equipment were acting up and they were unsure as to why. When the electrician measured phase to ground (~575V), the meter had an internal arc and pulled a arc on the terminals of the receptacle when he attempted to pull away. The meter was a Southwire meter, they eventually had to pull it due to a failed IP67 rating, you could try googling MSHA (Mine Safety and Health Administration and Southwire) and you might find something I'm not sure. I believe the IP67 failure was not a factor in the accident but it came up during the investigation.
I would like to know how often in the real world a surge or some other anomaly comes along and puts a technician at risk while in the process of troubleshooting a fault in a piece of (let's just say consumer) equipment.
My guess - not very damned often. Techs love the Fluke 87 and it's variants for a good reason. It's reliable and consistent, and safe. Period.
It is not necessary that it survive a gazillion volts at 1/2 height or whatever. In the EXTREMELY UNLIKELY event that it's ratings are exceeded in a given situation, the Fluke will "fail safe" and further - Fluke will fix it for FREE.
Meanwhile - you can rely on it's readings, accurate to a level exceeding spec by an order of magnitude even if the meter is over thirty years old.
What more can you ask from a multimeter for it's intended function?
I'm a Fluke fan-boy?
You bet - and for good reason.
While I'm not sure about the frequency of the surges, without a doubt they do happen. A local employer, a mining operation, had a electrician injured when he was measuring receptacle voltage (995V Phase to Phase), apparently the PT's onboard the equipment were acting up and they were unsure as to why. When the electrician measured phase to ground (~575V), the meter had an internal arc and pulled a arc on the terminals of the receptacle when he attempted to pull away. The meter was a Southwire meter, they eventually had to pull it due to a failed IP67 rating, you could try googling MSHA (Mine Safety and Health Administration and Southwire) and you might find something I'm not sure. I believe the IP67 failure was not a factor in the accident but it came up during the investigation.
I was actually referring to consumer level equipment repair. The mere thought of high energy stuff scares the crap out of me.
My training pretty much ends where the plug goes into the wall.
I would like to know how often in the real world a surge or some other anomaly comes along
I would like to know how often in the real world a surge or some other anomaly comes along
It definitely happens.
Please forgive my ignorance, could you please describe under what conditions this happens? And what happens?
I see a lot of discussion here that these cheap-ass multimeters are "low voltage only". Yet *none* of them failed to measure voltage in mains. I also didn't see meters failing below 1kV. So, where the danger comes from? (assuming probes are of any decent quality).
My next question would be how failing to survive a "high-energy test" compromises safety (if the meter does not completely explode, of course).
My next question would be how failing to survive a "high-energy test" compromises safety (if the meter does not completely explode, of course).
Fluke has some good info on their website.
That's the thing - they often do explode. Watch the videos in this thread
There can be dangerous power surges in the mains due to nearby lightning strikes or faults in the distribution system that allow high voltages to jump over onto the low voltage side. The usual impact of this is to damage equipment in your house like televisions or computers, or in the worst case to set your house on fire.
I was waiting for this comment :)
How many meters actually exploded just by connecting to mains?
If I repaired consumer products or just considered how often my own AC line powered equipment has been damaged in my house over my lifetime, would I somehow feel it relates to what can happen through out the world under all conditions? Would I ever suggest that any of the testing I show has anything to do with how safe a meter would be if exposed to a real surge condition? Of course not.
I would imagine there are people who believe jumping a fuse with wire is an acceptable practice for all environments. It may very well be a person could be fine in their little bubble.
My interest has always been in low energy robustness. That's why I make a bigger deal about the EMC than the safety standards. It's not that I don't care about safety as much as it is rare I am at risk in the home hobby lab.
I can understand owning an expensive meter like the 87V, having total confidence in it and then with all your love for the meter, someone comes along and shows that it can be damaged at levels that many low cost meters also fail at. Rather then simply acknowledge it, you choose to defend it and claim the tests have nothing to do with what you do in real life. That's all fine. I see the same response from many of the meters I run. I would expect that if I ran Dave's 121GW and it failed the puny grill starter test, Dave would defend that the test was pointless and not how it is conducted in the real world.
But again, that's not why I run the tests. I have no love for any meter. I would toss the Brymen aside if I found something I liked better. I run them against a standard to see how electrically robust they are with one another. I can't help it if you feel Fluke got a bad shake in the testing. I run the test and present the findings. If you have no interest in watching the videos and feel there is nothing you can learn from them, to be honest I don't understand why you are wasting your time with them.
...And don't forget HRC fuses that I recently was schooled on how they can easily be replaced with wire. I do like the slot cut into the case to allow for maybe an external power supply. Good stuff.
I bet your car has seatbelts and airbags though. :popcorn:
...
Enough that they eventually developed some standards and safety ratings.
My intention was not to diminish your tests or your results, but I do think my question was valid on it's own. Possibly it might have been better posted in another context. By all means do keep it up and I don't feel I'm wasting any time watching your videos.
And as for learning - there's no doubt in my mind your training and experience is an order of magnitude better than mine, if not more.
I do cringe a little at some of your tests...
Sadly, all the safety codes and regulations are designed to guard against the ignorant, the people who don't know what they are doing. This is called "the nanny state". It's a shame, but I guess we have to live with it.
I have a ceiling fan and needed to replace its switch. Drove to all the local stores and could not find one switch that was UL rated. This switch has the potential to cause an electrical fire. I would GLADLY pay for a good certified switch but there are none to be had. We do not make them here anymore that I have found. I doubt the average consumer will care unless something happens. Even then my guess is the finger would be pointed at the installation and not the switch itself. There used to be public service announcements to help educate the general population about things like UL. Now we talk about quality rather than practice it. Fan I would guess is I would imagine nearing 40 years old now. The larger white switch is make by KTE and was the original The smaller switch is what I used to replace it. Note the CSA and RL marks on it. The pull mechanism in this switch failed in maybe 5 years or so. That's how bad the quality is. The new switch is even cheaper made with no cert.
Keeping stats like this I'm sure is a mental illness of sorts, like stamp collecting.
About home appliances, they have their own safety ratings, for now. Like the switch, I am not suggesting all the crap we import is certified for safety. The outside metal cases are grounded. Double insulation, single ground point. Bond wire testing. HI-POT testing. Nothing like a hand held device you would hold in your hand while you are probing mains. Not that someone could not rewire their microwave to short the two lines together while the covers are off with no fuse in place, but I have seen a few crap meters that had no fuse where someone could easily do just this, short the lines. And even if you did own a meter that had HRC fuses to help protect you, nothing prevents you from being stupid and shorting out the fuse with a wire.
Again, I have little to no interest in multimeter safety because I do not work in an industry where it concerns me and I know enough to limit my own risks at home.
If I Google "electrical fatality statistics", there's all sorts of information that comes up. I added the word "multimeter" to the search (this stuff is not rocket science). Now here is an interesting article. Could be a fear based ad still.
http://iaeimagazine.org/magazine/2008/07/16/multimeter-accident-prevention-plan-an-electrical-inspectors-survival-guide/ (http://iaeimagazine.org/magazine/2008/07/16/multimeter-accident-prevention-plan-an-electrical-inspectors-survival-guide/)
...
I can always count on you adding to the technical discussion. :-DD Did you need to add or remove a period? :-DD
They had to remove the carpets on the ISS:
They had to remove the carpets on the ISS:
It's all extra weight, and accidentally dropping one isn't much of an issue up there.
My intention was not to diminish your tests or your results, but I do think my question was valid on it's own. Possibly it might have been better posted in another context. By all means do keep it up and I don't feel I'm wasting any time watching your videos.
And as for learning - there's no doubt in my mind your training and experience is an order of magnitude better than mine, if not more.
I do cringe a little at some of your tests...
I am not a repair tech nor am I an electrician. I am open to discussing your thoughts about the testing I have done. It's not like there is a pool of information where there are industry standards on how to benchmark meters for their electrical robustness. This is what happens when you take a simple idea like "I wonder if a cheap $50 meter is more robust than a $400+ meter" and act on it. Because it's not something that is commonly done (maybe never) it leads to confusion. Then we have the internet with it's vast pools of experts on the mater. After a couple of years, it seems we have heard it all.
There is little you or anyone could post that would diminish the testing I have done to date. It's just data to me that I collect it and present. Everything is open as far as what I have done. If you feel your 87V is "reliable and consistent, and safe. Period" that's all fine. Your personal feelings do not go against anything in the data I have shown for the 87V. I have never collected data for safety or reliability. Nor have I studied what I would consider makes a meter consistent. So I won't disagree with you as I have no data that says otherwise.
I am only looking electrical robustness and the 87V is just not very robust when compared with some of the other meters I have looked at. I will give you that the 87V is way more robust than the UNI-T's that failed the puny grill starter test. That has become a standing joke around here. Even my wife will ask, "did it fail the grill starter" :-DD
What's to cringe at? :-DD The energy levels are fairly low, I have a fair amount of safety checks built into the generator and if I play with something that may pose a high risk it's behind a half inch thick plate of Plexiglas (more to protect the camera). Any time I play with the half cycle generator, I am a fair way away and out of the direction of the blast. The risk is low for me but it's not something I would suggest the fuse jumping crowd get involved with.
https://www.copeplastics.com/plexiglas-impact-resistance.html (https://www.copeplastics.com/plexiglas-impact-resistance.html)
I just cringe at the impending destruction of a perfectly decent (for most of us anyway) meter. It's cool you're able to fix most of them however.
Yeah, kids in Africa could have eaten those meters! :palm:
When will we see part 2 on the Gossen? The suspense is killing me!
Would the Fluke 114, 115, 116, 117 series survive carpet surfing reasonably well such as the 101 or 107?
I need the TrueRMS, min max and Low Z features which 101 and 107 lack
My 114 has held up well so far, not that I have done any serious deliberate carpet surfing with it.. yet
That said, if I have to spend $100 (on yet another meter :-\ ) that will survive carpet trekking in an office to office client troubleshoot scenario,
what choice is there ? :-//
BTW: what's the continuity buzzer like on the 101 and 107? If it's not typical 'Fluke Speed' the meter is a no go for me.
Thanks, I will assume the 114 and 115 will have same performance being the same build style
and same deal with 101 and 107
Would you know how well the continuity buzzer on the 101 and 107 compares to the 115?
...
I can always count on you adding to the technical discussion. :-DD Did you need to add or remove a period? :-DD
I posted a link to a picture of a nasty exploded glass fuse inside a meter... then I thought it might not be such a good idea, and I couldn't delete the post...
...
I can always count on you adding to the technical discussion. :-DD Did you need to add or remove a period? :-DD
I posted a link to a picture of a nasty exploded glass fuse inside a meter... then I thought it might not be such a good idea, and I couldn't delete the post...
Ah, mystery solved. In such cases perhaps it would be helpful to put something similar to "-- post deleted --" in the body to minimize confusion, speculation, and the like.
I have a ceiling fan and needed to replace its switch. Drove to all the local stores and could not find one switch that was UL rated. This switch has the potential to cause an electrical fire. I would GLADLY pay for a good certified switch but there are none to be had. We do not make them here anymore that I have found. I doubt the average consumer will care unless something happens. Even then my guess is the finger would be pointed at the installation and not the switch itself. There used to be public service announcements to help educate the general population about things like UL. Now we talk about quality rather than practice it. Fan I would guess is I would imagine nearing 40 years old now. The larger white switch is make by KTE and was the original The smaller switch is what I used to replace it. Note the CSA and RL marks on it. The pull mechanism in this switch failed in maybe 5 years or so. That's how bad the quality is. The new switch is even cheaper made with no cert.
While I'm not sure about the frequency of the surges, without a doubt they do happen. A local employer, a mining operation, had a electrician injured when he was measuring receptacle voltage (995V Phase to Phase), apparently the PT's onboard the equipment were acting up and they were unsure as to why. When the electrician measured phase to phase the meter had an internal arc and pulled a arc on the terminals of the receptacle when he attempted to pull away. The meter was a Southwire meter, they eventually had to pull it due to a failed IP67 rating, you could try googling MSHA (Mine Safety and Health Administration and Southwire) and you might find something I'm not sure. I believe the IP67 failure was not a factor in the accident but it came up during the investigation.
Edit: Found it https://arlweb.msha.gov/Alerts/Equipment/2014-11-21-southwire%20alert.pdf (https://arlweb.msha.gov/Alerts/Equipment/2014-11-21-southwire%20alert.pdf)
I would like to know how often in the real world a surge or some other anomaly comes along and puts a technician at risk while in the process of troubleshooting a fault in a piece of (let's just say consumer) equipment.
I am not an expert in this area, but I think that outcry may have happened and thus HiPot testing is used to address this concern for consumer electronics and appliances. Reading this article (http://electrical-engineering-portal.com/what-is-hipot-testing-dielectric-strength-test) seems to confirm that.I would like to know how often in the real world a surge or some other anomaly comes along and puts a technician at risk while in the process of troubleshooting a fault in a piece of (let's just say consumer) equipment.
Since I discovered this site which has always stressed getting meters that meet their CAT ratings, I have wondered the same thing myself, only from a slightly different perspective, I always felt that if these surges were so common place, then there'd be be tons of folks crying about their busted electronics, like their 'spensive, flat screen, UHTV's, computers, smart phones (while charging), etc. I am sure they are not "hardened" for what would be considered CAT 2 transients, like a Fluke or other reputable multimeter, so there should be many failures of these kinds of equipment. And, if it were really a problem, there'd be an outcry to harden electronics to survive these transients. At least in the US, you don't really see that, which leads me to believe overall the US has fairly clean electric supply (as opposed to generation, but that would be a different discussion ::)), but as others have said, that may not be the case in other parts of the world, so a meter that meets its CAT rating may be more of a necessity in those areas.
I have not known anyone who has lost a piece of electronic equipment due to a transient unless lightning was involved.One example of non-lightning issue is what I saw happen in my hometown (1980s in Brazil): a neutral ground interrupt fault, which raised the voltage of the phase wires to the point of internally arcing and damaging some of the consumer equipment and appliances. That was dangerous but fortunately there were no cases of electrocution.
Reporting the fault in the German language should provide a quicker answer.
I doubt such a mV behavior would be acceptable to Gossen. That meter must be faulty, but we shall see.
mailto:Support.industrie@gossenmetrawatt.com
http://gossen.ofactory.biz/services/produkt-support/allgemeine-hinweise/ (http://gossen.ofactory.biz/services/produkt-support/allgemeine-hinweise/)
I can't imagine the thing isn't shielded inside. Maybe the shield isn't connected properly.
Take it apart and have a peek inside.
I don't have the same meter, but I can report that the Gossen MetraHit 30M, which reads down to 100nV doesn't behave like that at all. It only shows some minor fluctuation on the last digit.
The MetraHit 26S, with has a resolution of 10uV, is rock solid, to the last digit.
Reminds me of the Apple iPhone 4 "Antenna Gate" debacle.
In addition to the email you sent them, send a link to this thread and the 2 YouTube videos you made. You may find you get a faster response as few companies want any negative comments or findings spread on the internet.
I can't imagine the thing isn't shielded inside. Maybe the shield isn't connected properly.
Take it apart and have a peek inside.
Removing the cover voids the warranty. From watching Dave's video on the Energy, I suspect there are other latches and that is why he uses the screwdriver. Maybe the meter broke when he pried it apart? I have no idea. I asked. I will pull one of them apart at some point and it would be good to know if there was a trick to getting it apart.
The other problem with taking it apart is like we saw in one of Dave's recent mailbag videos were he was sent a box of brand new meters. He does a quick teardown and then the meter does not work. It raises questions if the meter was damaged during the teardown. We have no idea.
This meter (or another of the same model) will come apart once I have completed all of my basic tests. I want it to be VERY clear to people that this is how the meter worked when I received it.
https://www.eevblog.com/forum/blog/eevblog-173-gossen-metrahit-energy-multimeter-teardown/ (https://www.eevblog.com/forum/blog/eevblog-173-gossen-metrahit-energy-multimeter-teardown/)
This thread is a meter review and as such, looks at all the features of the UT71D. What I use the meter for is irrelevant.
I've gotta say I'm surprised at the Gossen so far (Not that I'd heard of them before EEVBlog), they are held in high esteem but it seems like from these tests its nothing special.
these "tests" are purely for entertainment... I wouldn't base any decisions on them whatsoever...
Same here. When you see the meters failing at somewhat midrange through the voltages, the interpretation one can make of Joe's tests leave a lot of wiggle room in terms of comparison. However, when one fails at the edges it gives you much more to think - especially when a random unit fails with a simple spark.these "tests" are purely for entertainment... I wouldn't base any decisions on them whatsoever...
I disagree. Anyway, feel free to propose your tests.
Read the manual. None of the Gossens have a Peak mode, except for the Gossen Energy. Testing a feature that doesn't exist. :-DDThe Gossen does have a Rapid Momentary Value Acquisition mode with data store so can capture (close to) peaks I guess but not a simple peak mode.
I think a Peak mode is useful, if only to work out the crest factor, but for some reason, Gossen thinks differently.
So thats why nobody else uses relays in handheld meters :P
It's certainly conceivable that in industrial use similar magnetic fields sould be experienced.
I wonder if you can flip the relay into the 'wrong' state by bashing the meter.
Scaremongering again.
The meter passed all electromagnetic requirements for multimeters.
Just don't take it with you for your next MRI scan and mind those tooth fillings too...
Electromagnetic Compatibility (EMC)
Interference emission EN 610326-1:2006, class B
Interference immunity EN 610326-1:2006 EN 610326-2-1:2006
Americans can't make meters either, the Fluke 185 and 867B, just to name a few, also have relays.
Scaremongering again.
The meter passed all electromagnetic requirements for multimeters.
Just don't take it with you for your next MRI scan and mind those tooth fillings too...
Americans can't make well engineered meters either. The Fluke 185 and 867B, just to name a few, also have relays.
Scaremongering again.
The meter passed all electromagnetic requirements for multimeters.
Just don't take it with you for your next MRI scan and mind those tooth fillings too...
Electromagnetic Compatibility (EMC)
Interference emission EN 610326-1:2006, class B
Interference immunity EN 610326-1:2006 EN 610326-2-1:2006
Americans can't make well engineered meters either. The Fluke 185 and 867B, just to name a few, also have relays.
I wonder what it would do with a strong DC field. Very high magnetic field strength electromagnets are used heavily in the mining industries for separation of metallic contamination (I'm supposing this is also used in several other industries for the same reason- but mining is the only one I have experience with).
So... don't ever put it in a toolbox near anything magnetic.
I'm with joe, this is a dangerous, recall-worthy problem.
So... don't ever put it in a toolbox near anything magnetic.Me too.
I'm with joe, this is a dangerous, recall-worthy problem.
Relays can be badly affected in strong magnetic fields, as warned by manufacturers. So can Rolex watches.
Just keep your neodymium magnets far away from expensive tools.
To stay out of trouble, always follow the old adage of measuring known voltages, before testing unknown ones.
You could procure a genuine $70 GMW magnet to go with this meter.
https://www.amazon.com/Gossen-Metrawatt-Z117A-Magnetic-Holder/dp/B0128DNNDC (https://www.amazon.com/Gossen-Metrawatt-Z117A-Magnetic-Holder/dp/B0128DNNDC)
They only work with the rubber boot on and may not be as strong as the one you played with.
If there is a magnetic interaction with the holder, then I'll agree that Gossen should at least warn their customers.
The Fluke 185 relay is also affected by a strong neodymium magnet held to the back of the meter, but only if taken out of its boot.
The 8 pound magnet at the tip of my magnetic wand had no effect.
The Fluke 867B case is so big, only the LHC may affect it in any way.
https://www.amazon.com/Magnetic-Telescoping-Retriever-Telescopic-Retrieving/dp/B0175B3VRU (https://www.amazon.com/Magnetic-Telescoping-Retriever-Telescopic-Retrieving/dp/B0175B3VRU)
When you remove the magnet and power off the meter.What happens when you power it on ?
When you remove the magnet and power off the meter.What happens when you power it on ?
Nothing. It stays "broken" until you do something that clicks the relay, eg. select Ohms range.
Watch the video:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1216462/#msg1216462 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1216462/#msg1216462)
When you remove the magnet and power off the meter.What happens when you power it on ?
Nothing. It stays "broken" until you do something that clicks the relay, eg. select Ohms range.
Watch the video:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1216462/#msg1216462 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1216462/#msg1216462)
Well, when you get reviewers of test gear (including Dave) spending time ranting about how "cheap" or "toyish" an equipment looks, you end up amplifying the feel that a teat gear has to also score high on this criteria - the manufacturers will pay attention to the reactions, given this may get some impulse buy, especially on the low-end.
Well, when you get reviewers of test gear (including Dave) spending time ranting about how "cheap" or "toyish" an equipment looks, you end up amplifying the feel that a teat gear has to also score high on this criteria
And Keysight, Gossen, Fluke and all bigo ones.... none of them are sacred cows... I don't necessarily agree with every test Joe does, or even his conclusions sometimes.. But I love his irreverence and lack of idolatry.... Premium manufacturers are not faultless, and us being critical to them, instead running sorts of cults that worship certain brands, is good.
It is good to us (better products for us) , it is good for them ( we keep them honest ) in a long run.... And it is even better for second tier manufacturers and us.. It makes them try harder...And give us better affordable products...
I do not want to defend Joe's "crusade" on the Gossen meter ( I think he does a bit of drama on purpose.. It's how you stir up the people ), but I agree with him on general principle :
If I pay for a handheld as much as for a good 6.5 Digit Benchtop meter, I want it to be better, more robust and superior in every TECHNICAL aspect to a Brymen or whatever else out there.. I want it to have Mu metal shield, 2ppm/C stable reference, etc, etc... It has to an overkill on specs..
Otherwise why on earth would I buy it... If it's not actually better?
For the price you can buy FLUKE 87V AND Brymen 869S ... Or Brymen 869S AND FLUKE 289 ... And all three of those are very good... And will do the task of measuring at least as good...
My 2c and million words... Sorry for verbosity..
P.S. Should I mention Japan and motorbikes ;D
3DB
P.S. Should I mention Japan and motorbikes ;D
3DB
Just bikes in general are always a good topic. The faster / quicker, the better!
They only work with the rubber boot on and may not be as strong as the one you played with.
If there is a magnetic interaction with the holder, then I'll agree that Gossen should at least warn their customers.
The Fluke 185 relay is also affected by a strong neodymium magnet held to the back of the meter, but only if taken out of its boot.
The 8 pound magnet at the tip of my magnetic wand had no effect.
The Fluke 867B case is so big, only the LHC may affect it in any way.
https://www.amazon.com/Magnetic-Telescoping-Retriever-Telescopic-Retrieving/dp/B0175B3VRU (https://www.amazon.com/Magnetic-Telescoping-Retriever-Telescopic-Retrieving/dp/B0175B3VRU)
When you remove the magnet and power off the meter.What happens when you power it on ?
3DB
Gossen is well aware of the interaction, warns about it and lists the meters affected:
P.S. Should I mention Japan and motorbikes ;D
3DB
Just bikes in general are always a good topic. The faster / quicker, the better!
Around these parts we call motorcycle riders "organ donors."
I'd rather take my chances poking around in a 480V 3ph panel with a DT830 multimeter...
Hard to think Gossen wouldn't have checked the meter for that eventuality.
If it does happen with their holder too, and all indications are that it may, they should advise customers to keep magnets away from the meter until they update the software, to make sure the relay is on the right connection at power up.
My point is that Japan started from nothing and became a MAJOR player in the Motorbike and car industry.
The established companies were complacent and didn't see this until it was to late.
:palm:
It may be just a quick to use the ohms mode to reset versus a power cycle each time the meter was setup.
It may be just a quick to use the ohms mode to reset versus a power cycle each time the meter was setup.
One of those is unsellable. People would laugh at you if you told them to switch to Ohms mode before every reading.
The 'solution' is magnetic shielding and pulse the relay whenever you select a range that depends on it.
PS: Google tells me they manufacture magnetically shielded relays with metal cases especially for applications like this. So much for Gossen's "100 years of experience". :popcorn:
Have you tried whacking it yet?
Have you tried whacking it yet?
Whacking is not very scientific.
Have you tried whacking it yet?
Whacking is not very scientific.
Exactly what I predicted (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1216365/#msg1216365) you'd say (on the previous page).
It's fun though, and might give you an idea of how easy/difficult it is. :popcorn:
One problem: He likes to quantify things and "slapping" is unscientific. I can't wait to see the machine he invents for this. :popcorn:
Looks like the low end company is stepping up and doing the right thing with a recall over a similar problem as this Gossen. Gossen's technique is just ignore it's customers. Really sad.
https://www.cpsc.gov/Recalls/2017/extech-recalls-digital-clamp-meters (https://www.cpsc.gov/Recalls/2017/extech-recalls-digital-clamp-meters)
Have you every heard anything from Gossen? For the price of this meter you would think customer support would be top notch.
One problem: He likes to quantify things and "slapping" is unscientific. I can't wait to see the machine he invents for this. :popcorn:I wonder how my wife would feel about setting up small environmental chamber with a vibration table in the living room.
QuoteOne problem: He likes to quantify things and "slapping" is unscientific. I can't wait to see the machine he invents for this. :popcorn:I wonder how my wife would feel about setting up small environmental chamber with a vibration table in the living room.
A vibration table lets you accurately compare meters against other models but it doesn't give you any feel for how easy it is to do the real world. For that you need to slap it around a bit.
throw 'em in the dryer machine...
throw 'em in the dryer machine...
FedEx it to yourself. :scared:
QuoteOne problem: He likes to quantify things and "slapping" is unscientific. I can't wait to see the machine he invents for this. :popcorn:I wonder how my wife would feel about setting up small environmental chamber with a vibration table in the living room.
A vibration table lets you accurately compare meters against other meters but it doesn't give you any feel for how easy it is to do the real world. For that you need to slap it around a bit.
The meter survived shipment to my house across the ocean. I would guess it saw some pretty big changes in temperature, pressure and vibration.Welll ... Oceans don't really vibrate or shake. It's more heave and roll.
The problem is how do you quantify and reproduce it?
I'm not going to buy an $800 for a meter just to do that test but it might be interesting to get a couple of transparent-cased relays with similar G-ratings and tap them to get an idea of what the G-ratings translate to in tangible terms.You should not expect people to do something you are not willing to do yourself. It's fine to ask but don't expect it.
A one meter fall on a hard surface is likely to damage the relays, especially if the meter is dropped without its rubber boot.
Drop face first on concrete and feel the effect of 100g. >:D
Yep, G force numbers look big on paper but a sharp tap can easily produce hundreds of Gs for an instant.
Real engineers carry their meters in huge foam padded cases and only take them out on site.
What would you do if you dropped your meter as you took it out of the case on site? Say 'sorry I can't use that' and come back next day? :popcorn:
You should not expect people to do something you are not willing to do yourself. It's fine to ask but don't expect it.
I know you're waiting for Brymen...
Gossen
The meter survived shipment to my house across the ocean. I would guess it saw some pretty big changes in temperature, pressure and vibration.
I already gave the example of driving across a farm with the meter loose in the back of a pickup truck. That's real world, it could happen.
You should not expect people to do something you are not willing to do yourself. It's fine to ask but don't expect it.
I don't have currently one of those meters on my table with the intention of doing bad things to it later. If I did I wouldn't be against a few more knock tests.
I know you're waiting for Brymen(*) to comment before opening it up, etc. Maybe you can do the bashing after all the electrical testing is over and the back is off. You could attach some wires to the relay and flash a LED when it changes position - it doesn't matter if the meter is dead or alive for that.
Is a test of the of the fancy input-jack-blocking mechanism's robustness also in the agenda? I believe there was interest shown earlier.
Edit: I meant Gossen, of course.
The meter survived shipment to my house across the ocean. I would guess it saw some pretty big changes in temperature, pressure and vibration.
I already gave the example of driving across a farm with the meter loose in the back of a pickup truck. That's real world, it could happen.
In your world maybe, not in mine. ;)
The worst shock my meters get is when they flip over on the bench in my lab.
...
Safety is probably not as big thing for my job as for others. But I'm glad it is safe. As long as it survives stupid things like probing 350VDC in a smps still in diode or resistance mode I'm happy. I have 2 HV probes and for current I use shunts, clampmeters, current probes and a fluxgate probe.
The big 440mA fuse of my Agilent failed, I have no clue how, maybe when the charger or a battery failed. I never use it for current. So I rebuild the big 440mA fuse with parts of a panel-fuse holder and dropped a small glass-fuse in it. The only current it sees is from the charger.
After Joes videos I'm thinking about a Brymen 869s as a second handmeter. I'm not a Fluke fanboy, I could cuff up lot of money I probably bought a Keysight (one with the oled screen).
In your world maybe, not in mine. ;)Don't you have any curiosity about the physical limits of this meter?
What makes you think I have not given up on Gossen and that the meter is still together? Do you really feel that I have not already done bad things to it or that its not damaged beyond repair already?It's open and the soldering iron's out. :scared:
In your world maybe, not in mine. ;)Don't you have any curiosity about the physical limits of this meter?
You're the one posting in this multimeter testing thread, you tell me... :popcorn:No, should I ?In your world maybe, not in mine. ;)Don't you have any curiosity about the physical limits of this meter?
Don't link me your meter on a rope video.Says the guy who climbs on the roof of his house to throw meters off it. :popcorn:
Didn't see any throwing.....just careful release (liberation) into the atmosphere.Don't link me your meter on a rope video.Says the guy who climbs on the roof of his house to throw meters off it. :popcorn:
Didn't see any throwing.....just careful release (liberation) into the atmosphere.Don't link me your meter on a rope video.Says the guy who climbs on the roof of his house to throw meters off it. :popcorn:
That in itself is also valid information to add to the choice of a DMM to buy...........those that can be clipped back together and continue to be used. :phew:
Don't link me your meter on a rope video.Says the guy who climbs on the roof of his house to throw meters off it. :popcorn:
They were all heading to the recycle bin. Your soap on a rope was a perfectly good meter.
All ?They were all heading to the recycle bin. Your soap on a rope was a perfectly good meter.
Yours were all perfectly good when they arrived at your house and damages suffered in-between weren't accidental.
That's a matter of opinion.So is joe's assertion that my DT830 was a "perfectly good meter" before I tied a string to it and towed it behind a canoe.
They were all heading to the recycle bin. Your soap on a rope was a perfectly good meter.
Yours were all "perfectly good" when they arrived at your house. Damages suffered in-between weren't accidental.
That's a matter of opinion.So is joe's assertion that my DT830 was a "perfectly good meter" before I tied a string to it and towed it behind a canoe.
That's a matter of opinion.So is joe's assertion that my DT830 was a "perfectly good meter" before I tied a string to it and towed it behind a canoe.
Based on your in depth functional test, yes.
That's a matter of opinion.So is joe's assertion that my DT830 was a "perfectly good meter" before I tied a string to it and towed it behind a canoe.
Based on your in depth functional test, yes.
By that definition it's still a perfectly good meter!
All I managed to break was the battery and the case. The meter is in a drawer and still powers on and measures.
I'm more interested in a test that would leave your meter looking perfect on the outside but with the relay changed inside. eg. If it's on the stand and topples over onto a hard screwdriver handle.
Again: The point of slapping it around a bit is just to get a feel of what it takes to move the relay inside the meter. It was never meant to be a rigorous or accurate measurement, just a starting point for (possibly) further tests.
One safety standard for electrical equipment (IEC 61010) specifies that a product must survive a one meter drop at both its highest and lowest specified operating temperatures. (quote from a Fluke document)Interesting.........I was always under the impression the drop test was for 2 meters, I must have had that wrong. :palm:
just wanted to say,
dropping a meter off the roof or down some stairs is perfectly valid,
we dont all work from a desk!!
a have had meters go down stairs, drop about a meter onto concrete - several times, had to use them in the rain, and a few other misshaps too.
droptest should always be done with probes attached btw,
because it often lands on them and can stress the sockets or pcb if your unlucky.
One safety standard for electrical equipment (IEC 61010) specifies that a product must survive a one meter drop at both its highest and lowest specified operating temperatures. (quote from a Fluke document)
Does it auto-range on the resistance mode that quick or did you cut it out of the video?
Here's what happened: (German accent->on)
Marketing: We need a Bluetooth multi-meter, Bluetooth is really cool..
Engineering: That's silly, who would use that, and think of the all the work involved.
Management: can't we put in some standard module to save a lot of work? Work=money you know.
Engineering: Yes but think of the rf interference caused in this precision device, and to fit the bloody
BT module we must leave out the standard shield, that could cause all sorts of trouble!
Management: Leave out the standard shield you say? Very good! Those are outsourced and cost 43 cents each and 16 seconds of manual assembly time, great!
What a good day it is to be a manager.
(German accent->off)
Does it auto-range on the resistance mode that quick or did you cut it out of the video?
Here's what happened: (German accent->on)
Marketing: We need a Bluetooth multi-meter, Bluetooth is really cool..
Engineering: That's silly, who would use that, and think of the all the work involved.
Management: can't we put in some standard module to save a lot of work? Work=money you know.
Engineering: Yes but think of the rf interference caused in this precision device, and to fit the bloody
BT module we must leave out the standard shield, that could cause all sorts of trouble!
Management: Leave out the standard shield you say? Very good! Those are outsourced and cost 43 cents each and 16 seconds of manual assembly time, great!
What a good day it is to be a manager.
(German accent->off)
If you want to see how fast the meter autoranges, I suggest watching the earlier videos. My functional testing takes too much time so I edit it down.
A few steps in the process:
Engineer: What about the safety?
Manager: Do we meet the letter of the law?
Engineer: IEC does not test with high magnetic forces like the $70 hanger we sell with the meter but it can cause the meter to be in an unsafe state.
Manager: Not our problem. We are not the experts writing the specs. As long as we meet the letter of the law we are good to go.
Safety inspector: Looks good to me.
Average Customer: Looks good to me.
Spouse of average customer after tragic event: Sniff..
Spouses attorney: We believe your spouse was not at fault and there may be a design flaw with the meter. We saw it on YT...
Several months go by:
Manager: Sorry engineer, we need a scape goat and you are it! In the mean time, I bought a new yacht with the bonus I got from all the money we saved. Clean out your drawers by the end of the day.
Several months go by:
Engineer takes the stand and has saved the emails and voice mails documenting the history on their personal cell phone.
In the mean time, Extech has finished with their recall of their clamp meters being the mid range supplier they are.
$800, 6-digit meter with no internal shielding at all?
:palm:
$800, 6-digit meter with no internal shielding at all?Here I thought nothing got by you. There is a shield on one side of the board.
I've never seen a Gossen meter with a metal shield on the back. Most have a plastic cover secured with one screw to the PCB. (The old models at least)
I checked the one fitted on the 30M. It doesn't seem to be conductive, unless there is perhaps an internal metallic layer.
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=49477.0;attach=156670;image)
https://www.eevblog.com/forum/testgear/adjustment-of-metrahit-18s-and-18c/?action=dlattach;attach=156669;image (https://www.eevblog.com/forum/testgear/adjustment-of-metrahit-18s-and-18c/?action=dlattach;attach=156669;image)
This PRO model has 2 shields, but they might both go in the front of the PCB:
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=79281.0;attach=275277;image)
https://www.eevblog.com/forum/repair/metrahit-pro-leaked-battery-repair-attempt/?action=dlattach;attach=275276;image (https://www.eevblog.com/forum/repair/metrahit-pro-leaked-battery-repair-attempt/?action=dlattach;attach=275276;image)
I'm curious now if there is a shield under that plastic cover in the first picture.
The second picture looks like the shields shown on Dave's Xtra. Makes sense they would keep them all the same. Maybe they felt it was not worth the cost to tool one for the BT model.
Also it makes me wonder if the Energy is sensitive to static like the Ultra. They appear to use a different relay. Maybe it does not have the same sensitivity.
$800, 6-digit meter with no internal shielding at all?
:palm:
Here I thought nothing got by you. There is a shield on one side of the board. If you watch Dave's video of the Xtra, you will see the same 4 PTHs where the second shield mounts to. That shield does not look like it would have worked for the Ultra BT.
The questions I have is does the A model (no BT) have a shield on the backside and is my B model missing a shield from the factory or was this by design? Because Gossen has had no contact with me and Dranetz went so far as to block my email over a simple question of getting the meter aligned, I doubt I will ever know.
My email address is fresh (unblocked), if you like I'll send "them", a single message with a link to this thread. You can PM me with their contact info, up to you, not much to lose at this point if you've somehow been blocked, which is really odd.
Also it makes me wonder if the Energy is sensitive to static like the Ultra. They appear to use a different relay. Maybe it does not have the same sensitivity.
Hi,
no, my Energy has no Problems with static discharging in all ranges.
It also has only one metal shield on the backside, at the topside is a plugin board with the power measurment processor.
It contains two Relais, not sure if this are the same type or not. (I assume they are different)
I was not able to trigger the relays with a magnet or a degausing coil, my magnet and the coil seems too weak for this.
But I did check this:
Switch the meter on and then set it from the V mode to resistor mode, one of the relais clicks.
Then I switched off the meter, set in the V mode and turned it on again. The relais was set back to the correct state, it worked as expected. (Firmware rev. is 1.20)
Regards
Second post about the need for a grounded shield on the relay. :-//
Dave's ghost meter is watching the surgery, knowing one day it will be his turn. :-DDAnd that day is getting closer. :)
Apparently some people think a grounded shield will block magnetic fields... :palm:
I like the case. It looks sharp with the zipper. Lots of detail. Of course, in the end, all that fluff won't help it survive the grill starter. Looking forward to seeing just how robust this little beast is compared with all the other meters I have looked at.
Protected yourself and your pacemaker from evil magnetic holders:
$65.95 only!
50% reduction of AC and DC magnetic fields!
Everything I have ever seen about Gossen just makes me think "Overpriced bullshit". These videos have not done anything to sway me from this at all.
Second post about the need for a grounded shield on the relay. :-//
Apparently some people think a grounded shield will block magnetic fields... :palm:
Everything I have ever seen about Gossen just makes me think "Overpriced bullshit". These videos have not done anything to sway me from this at all.
you have seen the wrong things and been misinformed by the whitch hunters...
Second post about the need for a grounded shield on the relay. :-//
Apparently some people think a grounded shield will block magnetic fields... :palm:
No, but it will help to reduce the "theremin" effect.
These are high count very specialized CAT III 600V only meters, with detailed calibration certificates.
Can they be made safer? Possibly, like most other meters. They do come though, with independent testing and meet current regulations.
There is always a premium on price when products are made in Europe and this one also comes with a meaningful 3-year warranty.
As for neodymium susceptibility, it is not very difficult to keep magnets at a safe distance and forego the use of magnetic holders.
It is a small price to pay, as nobody else yet makes a true 300,000 or 1,200,000 count portable meter and may never do.
So, enjoy them while you can, before they disappear completely, under pressure from Asian products.
Everything I have ever seen about Gossen just makes me think "Overpriced bullshit". These videos have not done anything to sway me from this at all.
These are high count very specialized CAT III 600V only meters, with detailed calibration certificates.
Can they be made safer? Possibly, like most other meters. They do come though, with independent testing and meet current regulations.
There is always a premium on price when products are made in Europe and this one also comes with a meaningful 3-year warranty.
As for neodymium susceptibility, it is not very difficult to keep magnets at a safe distance and forego the use of magnetic holders.
It is a small price to pay, as nobody else yet makes a true 300,000 or 1,200,000 count portable meter and may never do.
So, enjoy them while you can, before they disappear completely, under pressure from Asian products.
I'm enjoying it all right. Next part, we will see just how robust that front end is.
I doubt the average person would take the time to see if a magnetic strap would effect their new high count, very specialized CAT III 600V only meters, with detailed calibration certificates. I personally would have never thought they would release such a product.
ignore the troll with the "pee-zee-o"... that's what Gossen support said in regard to your emails to them... :-DD
That's not what they publish on their website.
These are high count very specialized CAT III 600V only meters, with detailed calibration certificates.
Can they be made safer? Possibly, like most other meters. They do come though, with independent testing and meet current regulations.
There is always a premium on price when products are made in Europe and this one also comes with a meaningful 3-year warranty.
As for neodymium susceptibility, it is not very difficult to keep magnets at a safe distance and forego the use of magnetic holders.
It is a small price to pay, as nobody else yet makes a true 300,000 or 1,200,000 count portable meter and may never do.
So, enjoy them while you can, before they disappear completely, under pressure from Asian products.
I'm enjoying it all right. Next part, we will see just how robust that front end is.
I doubt the average person would take the time to see if a magnetic strap would effect their new high count, very specialized CAT III 600V only meters, with detailed calibration certificates. I personally would have never thought they would release such a product.
You're such a drama queen. So concerned with minute safety aspects. This from someone who rides motorcycles, probably without a helmet too. These meters have been around for at least 20 years, how many people were actually hurt by their Gossen magnetic hanger?
if you're so concerned with magnet safety, there is nothing preventing you from contacting the IEC to ask them to change their recommendations.
I guess that you have to find anything contentious with the expensive meters on test, to keep your audience amused, even at times openly disparaging a review made by the owner of this site. By the way, why is his face on the first frame of one of your videos? Riding coattails?
Any electrician worth his salt would know that relays can be affected by strong magnets and Gossen warns about such eventuality.
All I know is that I'm not about to throw my 30M in the garbage on the strength of your 'review'. ::)
Have fun with the Ultra, but like the Energy, who doesn't know what the conclusion will be already?
As for the price, the Chauvin Arnoux MTX3293, also made in Europe, costs the same as the Gossen and you only get 100,000 count.
http://www.iec.ch/about/contactus/ (http://www.iec.ch/about/contactus/)
So basically, while Joe is right, meter is EMC sensitive more than we would like to admit (so we started process to improve it) we are royally pissed at Joe that he published this information to the public... And we don't speak to anybody that we don't like , even if the bought a 850 USD meter form us..... How dare he...:)
LOL
Yes, Joe Smith wrote a letter to the subsidiary in the USA. He targeted to receive a description of the interface protocol in order to calibrate the device by himself, which the subsidiary refused to release. This leaded to contrary positions and a not answering to his letter.
QuoteYes, Joe Smith wrote a letter to the subsidiary in the USA. He targeted to receive a description of the interface protocol in order to calibrate the device by himself, which the subsidiary refused to release. This leaded to contrary positions and a not answering to his letter.
Ouch! Whoever wrote that is going to get a roasting when the boss finds out. :-DD
That's not what they publish on their website.
That's what *everybody* says on their web site, even Batteroo.
QuoteYes, Joe Smith wrote a letter to the subsidiary in the USA. He targeted to receive a description of the interface protocol in order to calibrate the device by himself, which the subsidiary refused to release. This leaded to contrary positions and a not answering to his letter.
Ouch! Whoever wrote that is going to get a roasting when the boss finds out. :-DD
Whoever wrote that is going to get a roasting when the boss finds out.
If you red the reply carefully, you observed that the reply of GMC Germany was forwarded to me by the Managing Director of GMC France.
I'm curious now if there is a shield under that plastic cover in the first picture.
The second picture looks like the shields shown on Dave's Xtra. Makes sense they would keep them all the same. Maybe they felt it was not worth the cost to tool one for the BT model.
My metrahit 2+ appears to have the exact same shield as in the first photo and it hasn't a second shield underneath it, it must be some special plastics.
Always wondered what those randomly placed holes where for, now I know. :P
Edit: after 1 minute of google I've found this material:
https://www.rtpcompany.com/products/emi-shielding/ (https://www.rtpcompany.com/products/emi-shielding/)
The shield/cover is probably made out of something like that.
QuoteYes, Joe Smith wrote a letter to the subsidiary in the USA. He targeted to receive a description of the interface protocol in order to calibrate the device by himself, which the subsidiary refused to release. This leaded to contrary positions and a not answering to his letter.
Ouch! Whoever wrote that is going to get a roasting when the boss finds out. :-DD
If you red the reply carefully, you observed that the reply of GMC Germany was forwarded to me by the Managing Director of GMC France.
Personnaly, I was surprised to receive a so quick and frank reply, and would like to thanks GMC for that. It's not common these days ...
I also appreciate Joe's work, and I will let him to give us more details about his discussions with GMC USA.
Yes, Joe Smith wrote a letter to the subsidiary in the USA. He targeted to receive a description of the interface protocol in order to calibrate the device by himself, which the subsidiary refused to release. This leaded to contrary positions and a not answering to his letter.
Thanks for the fast response. I don't think calibration would be a problem. To be clear I am looking for companies that have the tools required to align the products without the need to ship it back to the factory. As I understand it, Gossen will sell these tools and I assume there are labs in the US that have invested in them.
I am not asking anyone to share tools, I am asking for a company in the US that can perform an alignment.
I am trying to determine if Gossen has anyone in the US that can perform an alignment of their handheld meters if they no longer pass calibration or do they need to be returned to Germany for alignment?
So basically, while Joe is right, meter is EMC sensitive more than we would like to admit (so we started process to improve it) we are royally pissed at Joe that he published this information to the public... And we don't speak to anybody that we don't like , even if the bought a 850 USD meter form us..... How dare he...:)
LOL
They clearly identified Joe as some motorcycle racing upstart , probably with zero letters behind his name ::) and not worthy of wasting ink on. :-DD
One can only hope they see the error of their ways and join up and jump in soon with something concrete about improving their Ultra...........free shields maybe ?
Joe, which other manufacturers have never bothered to offer a reply to your comms ?
QuoteYes, Joe Smith wrote a letter to the subsidiary in the USA. He targeted to receive a description of the interface protocol in order to calibrate the device by himself, which the subsidiary refused to release. This leaded to contrary positions and a not answering to his letter.
Ouch! Whoever wrote that is going to get a roasting when the boss finds out. :-DD
"Roasting", they are probably tied up right now, getting the GRILL starter treatment! :-DMM
I'm also keen to find out what happened to that Testo video which showed where their multimeters were prone to magnetic fields and in particular the supplied hanging strap, the video has been removed along with the comments, sorry I can't link from this device but it was discussed in mailbag #986 from memory.
"normal" users of this stuff are engineers - we laugh at security screws.Since when did a foreign screw stop you ?
and they know it! >:D
they could slap warranty seals over the screw holes or backfill them with epoxy though!!
Even when Brymen offered to repair the BM869s after they knew I had damaged it and how, I did not take them up on it. It's not their fault I run these meter to failure.
"normal" users of this stuff are engineers - we laugh at security screws.
Even when Brymen offered to repair the BM869s after they knew I had damaged it and how, I did not take them up on it. It's not their fault I run these meter to failure.
It is possible perhaps, that they might have liked to inspect the damage to see if they could improve the design? Sending you a good meter in exchange for the broken one seems like a fair trade to get back the damaged meter for examination (which I imagine is the most likely way they would "repair" it.)
I don't know why anybody would want to exceed 5V on a high frequency logic level (square wave) function. As per the manual, the range is protected up to 600V for 10s.
The meter can measure high voltage line frequency on other selections, without restrictions.
What I use the meter for is irrelevant.
1.2ms is a typo of course. IEC61010 requirement is for 1.2us rise time.Yes I pointed out that out during the first video, along with them calling out accessories that are not available to be purchased. The manual has a few areas that could use some help. 20 years you say? You would think by now they could correct some of these problems and polish is up a bit. I would say it's on par with other manuals from mid range meters.
I don't know why anybody would want to exceed 5V on a high frequency logic level (square wave) function.
You are disingenuous at best.
The Brymen 869 user manual is child-like compared to the information given in the Gossen technical reference.
When I say 20 years, I was referring to the older series, like the 30M for instance, which also has relays susceptible to strong magnets. I can't find any lawsuit seeking damages from Gossen. Can you?
Typos are everywhere, Fluke, Keysight, etc. Nothing to see here.
Quoting somebody out of context usually shows a lack of a convincing argument.
You're blowing smoke again. Most logic voltage level is still at 5V and lower. Most will find the Gossen range very useful.
Besides, no meter does everything. Get something else if it doesn't suit your specialized field.
Looking forward to the rest of the impartial review!
I don't know why anybody would want to exceed 5V on a high frequency logic level (square wave) function.
yes,
i would want it to function upto 24v or maybe even 48v
because i have used it to check sensors in cars.
you would be surprised what some company's will pay for.
even if it is stupid.
management arent the brightest staff on the payroll.
The fan boys simply never give up : :palm:We know that Joe loves his Brymen 869, but that's no excuse to pin labels on people. Kristallnacht is in the past.
The fan boys simply never give up : :palm:We know that Joe loves his Brymen 869, but that's no excuse to pin labels on people. Kristallnacht is in the past.
:palm:
You are disingenuous at best.
The Brymen 869 user manual is child-like compared to the information given in the Gossen technical reference.
When I say 20 years, I was referring to the older series, like the 30M for instance, which also has relays susceptible to strong magnets. I can't find any lawsuit seeking damages from Gossen. Can you?
Typos are everywhere, Fluke, Keysight, etc. Nothing to see here.
Quoting somebody out of context usually shows a lack of a convincing argument.
You're blowing smoke again. Most logic voltage level is still at 5V and lower. Most will find the Gossen range very useful.
Besides, no meter does everything. Get something else if it doesn't suit your specialized field.
Looking forward to the rest of the impartial review!
It will be interesting to see if Gossen comes up with a solution and what it is. I think they could fix the frequency input problem with firmware. The latching relay state change could be improved with firmware and using a shield around the relay. The proximity effect and sensitivity to the charged cloth can also be reduced by adding a shield.The fan boys simply never give up : :palm:We know that Joe loves his Brymen 869, but that's no excuse to pin labels on people. Kristallnacht is in the past.
What the fuck are you on about ?
Why can't you just accept the valid issues with this meter ?
Just because a company has a great reputation does NOT mean that they can't things wrong.
Gossen have already said they are going to sort it out. :palm:
GET OVER IT !!
3DB
Joe, when you have finished with Gossen, what about to test some meters (or better testers) which are directly meant to poke into mains with.
Would you be so kind to test this two UNI-T testers, which I often use for mains (instead of multimeters), but after seeing so much videos from you I am now not so sure if they are enough safe:
UT15C: https://www.amazon.com/Multifunction-Voltage-Tester-UNI-Trend-UT15C/dp/B0053X7HI2 (https://www.amazon.com/Multifunction-Voltage-Tester-UNI-Trend-UT15C/dp/B0053X7HI2)
UT18C: https://www.amazon.com/Voltage-Continuity-Indication-Battery-Detection/dp/B01AJJA6S2 (https://www.amazon.com/Voltage-Continuity-Indication-Battery-Detection/dp/B01AJJA6S2)
Technically they are multimeters IMHO (without Amp range - like Fluke 101).
A special drop test for Fungus
https://www.youtube.com/watch?v=hE8cJuza_2Q (https://www.youtube.com/watch?v=hE8cJuza_2Q)
Like this?
https://www.youtube.com/watch?v=i8pRlvgJw-o (https://www.youtube.com/watch?v=i8pRlvgJw-o)
A special drop test for Fungus
I'm so proud. :)
I guess the rubber helps a lot in those sort of drops.
We appreciate your findings about the sensitivity of the relay to magnetic fields and the possibility for a wrong AC voltage display. The relay has not caused a safety concern so far, because the possibility for a wrong AC display was not known. This is new to us and we shall have a risk assessment concerning this.
All your findings are under investigation in R&D. The target is of course an improvement of the device concerning its sensitivity to external electromagnetic fields. The solution shall of course become available for the serial production of the device, thus we cannot promise it short term, but we are targeting to make it available a.s.a.p.
Big thanks to Dave for sending one of the only two 121GWs he has. Looks like it will arrive next week.
Will it pass the grill starter? Stay tuned and find out.
The shield in the above pictures did not work so well. Back to the drawing board. Here is the final shield and other mods in operation.
https://www.youtube.com/watch?v=Jf_9XWL3TD8 (https://www.youtube.com/watch?v=Jf_9XWL3TD8)
Nice work!
Gossen will no doubt be offering a "joeqsmith" update/fix for $250.00, which may include the dust plug.
Let's not encourage the gent to expect a cut for the JQS Mod, and leave his current day job,
going hungry in the street waiting for a royalty cheque in the mail
"Will stress test and mod multimeter for food" :'(
I want to know if it'll survive a 1.21 GW burst. Joe, can you arrange to perform that test? :-DD
Sent from my iPhone using Tapatalk
Again, I run the meters out of my own interest and just share my findings. If I were doing it to make money, my current business model is flawed! And again, I want to thank everyone who has offered to help.
Somebody's badmouthing joe
https://www.eevblog.com/forum/testgear/fluke-87v-(2017)-lacking-quality-control/msg1229950/#msg1229950 (https://www.eevblog.com/forum/testgear/fluke-87v-(2017)-lacking-quality-control/msg1229950/#msg1229950)
Somebody's badmouthing joe
https://www.eevblog.com/forum/testgear/fluke-87v-(2017)-lacking-quality-control/msg1229950/#msg1229950 (https://www.eevblog.com/forum/testgear/fluke-87v-(2017)-lacking-quality-control/msg1229950/#msg1229950)
It's not badmouthing... I'm saying don't believe everything you read... if I wanted to badmouth, I'd call him a hack...
I have yet to see you post anything outside of trolling the forum. You are certainly welcome to point out what you feel I misrepresented. You could repeat the tests if you like and show your own data. Personally I would welcome you bringing something to the table for once rather then all your personal attacks on me and others over such trivial things.
That's quite a difference a little cleaning makes. I shall keep that in mind.
I am looking forward to Dave's DMM. Who manufactured it?
LOL! I love it how you have the grillstarter sitting ready to ignite. I'd just note this unit on your spreadsheet as "121GW prototype" so no one will complain if their unit turns out to behave differently. To me it seems quite obvious some kind of functional test is needed, so maybe Dave can comment on functionality he thinks is undesirable to review (en therefore test). I don't think Dave will be particularly obstructive in this respect. ;)
I think after showing the output of the grill starter and how it compares with the IEC standard, and yet damaging so many UNI-T meters, people will want to see if it will damage the 121GW.
Mr. JQS:
Is it possible/practical/insane to incorporate a real world 'carpet surf' Pass or Fail in your meter testing procedures?
or fast removal of a pullover garment that charges up ?
Mr. JQS:
Is it possible/practical/insane to incorporate a real world 'carpet surf' Pass or Fail in your meter testing procedures?
or fast removal of a pullover garment that charges up ?
Not really practical. It depends too much on the weather, etc.
Not really practical. It depends too much on the weather, etc.
Agree. Then again, drop testing a meter on the desk also has it's share of variables but I gave it a go just for you. :-DD :-DD
I think it would be good if you included the 'Mrs Smiths Fabric Test' in all future meter tests.
It can be the new electrostatic reference source. ;D
3DB
I was waiting for you to write a detailed test plan.
Now you know that's not a detailed set of test requirements.
Now you know that's not a detailed set of test requirements.
It's for those with SLIPPERY hands. Can't remember the last time I dropped my meter on a screwdriver, oh wait, now I remember, I've never dropped one, at all. :)
What were you measuring? ???I've very nearly dropped a meter into a cow pat. Wouldn't be much of an impact, but it'd definitely affect the measurements!Now you know that's not a detailed set of test requirements.It's for those with SLIPPERY hands. Can't remember the last time I dropped my meter on a screwdriver, oh wait, now I remember, I've never dropped one, at all. :)
[...]Yeah, but it still does happen. I think it is a fair requirement for a handheld meter to be able to survive falling without changing cal by ~30x as this one did. I can imagine the situations in which it is most important the value is correct (like when measuring the presence of mains) it is most likely the meter will fall (like when doing building activities or installation work). I can't remember when I last dropped a multimeter, but I don't do the aforementioned things.
It's for those with SLIPPERY hands. Can't remember the last time I dropped my meter on a screwdriver, oh wait, now I remember, I've never dropped one, at all. :)
What were you measuring? ???I've very nearly dropped a meter into a cow pat. Wouldn't be much of an impact, but it'd definitely affect the measurements!Now you know that's not a detailed set of test requirements.It's for those with SLIPPERY hands. Can't remember the last time I dropped my meter on a screwdriver, oh wait, now I remember, I've never dropped one, at all. :)
What were you measuring? ???I've very nearly dropped a meter into a cow pat. Wouldn't be much of an impact, but it'd definitely affect the measurements!Now you know that's not a detailed set of test requirements.It's for those with SLIPPERY hands. Can't remember the last time I dropped my meter on a screwdriver, oh wait, now I remember, I've never dropped one, at all. :)[...]Yeah, but it still does happen. I think it is a fair requirement for a handheld meter to be able to survive falling without changing cal by ~30x as this one did. I can imagine the situations in which it is most important the value is correct (like when measuring the presence of mains) it is most likely the meter will fall (like when doing building activities or installation work). I can't remember when I last dropped a multimeter, but I don't do the aforementioned things.
It's for those with SLIPPERY hands. Can't remember the last time I dropped my meter on a screwdriver, oh wait, now I remember, I've never dropped one, at all. :)
Seriously guys, you can calibrate the -carpet surf- test jig by walking (or 'surfing') across a fixed length of carpet with same slippers or shoes,As Fungus mentioned and if you read the couple of papers I had linked in the YT comments, the type of fabric will have a big effect. So will humidity. Your test plan is right there with Fungus's drop test. I think if you do a little research on how the ESD standards evolved (continue to evolve) you may find it interesting.
both selected to create a suitable electrostatic BANG! to a multimeter.
The brief ON and OFF pullover test can be done in any weather,
I don't expect Mr JQS to keep on a pullover for the duration of a Youtube video during inferno weather conditions
This can be the final word on real world "Handheld meter electrical robustness testing." for any meter! :-+
Assuming it first survives the screwdriver drop and cow pat test :scared: (Fluke 28-11 owners will love that s***) :-DMM
Dave reviewed the video and has approved it to be released. I will allow Dave to comment on the findings.
Even if it passed all the impulse tests, it will never be the best choice for those looking for the best high energy rated industrial meter (hence the lack of CAT IV rating, only CAT III, 600V max).
Even if it passed all the impulse tests, it will never be the best choice for those looking for the best high energy rated industrial meter (hence the lack of CAT IV rating, only CAT III, 600V max).
What?? But ... but ... 1.21 GW!!!
Troubleshooting 61010 impulse testing fails... don't impulse test because it's destructive and good luck finding out where the breakdown occurred.
Of course it's fast, it uses a flux capacitor!The CEM meters I have are really bad. So is the TPI.
(just don't go over 88Hz)
[...]The Metrahit changed about that ratio after being subjected to a magnetic field (I must admid I have not looked up the exact figure). I had assumed the drop test Fungus suggested was intended to provoke the relay changing this same way, that is why I mentioned it. Reading back the comments this might not have been the case. Excuse me for causing confusion... :-[
You saw a meter change 30X after being dropped?
This makes much more sense. Thanks for clearing it up. To be clear the ratio would be dependent on the input. The higher in voltage, the larger the ratio because the meter just clamps it. The PTC will just continue to drop more an more voltage. And of course, the relay did not change states in the drop testing (I use that word very loosely) I did but that does not mean that it can't happen. That's why I suggest the shield does not solve the root problem.[...]The Metrahit changed about that ratio after being subjected to a magnetic field (I must admid I have not looked up the exact figure). I had assumed the drop test Fungus suggested was intended to provoke the relay changing this same way, that is why I mentioned it. Reading back the comments this might not have been the case. Excuse me for causing confusion... :-[
You saw a meter change 30X after being dropped?
No problem, sorry for that. ;D I hadn't studied the exact workings of the relay, and just threw in the 30x remembering seeing about 4V when plugging into the 120V mains. The clamping behaviour is actually even worse, because it will then show roughly the same 4V when plugging it in to a way higher voltage than that. :palm:Yes, that is correct. I have not heard anymore from them but sure would like to see that risk assessment.
In the mean time, someone was asking about how Dave could justify the 121GW as a $200 class meter. The meter has a lot of unique features. Here is a sneak peek of the VA feature being used to measure the power dissipation of the 400mA ASTM fuse. Don't tell Dave I posted this.
https://www.youtube.com/watch?v=bn9m2sNmdw8 (https://www.youtube.com/watch?v=bn9m2sNmdw8)
In the mean time, someone was asking about how Dave could justify the 121GW as a $200 class meter. The meter has a lot of unique features. Here is a sneak peek of the VA feature being used to measure the power dissipation of the 400mA ASTM fuse. Don't tell Dave I posted this.
https://www.youtube.com/watch?v=bn9m2sNmdw8 (https://www.youtube.com/watch?v=bn9m2sNmdw8)
There was an error in your system setup here.
The error you are seeing was because you are not taking into account the insertion of the 121GW (and hence the small burden voltage of the 121GW) into your measurement. Your UT181 is not measuring at the same ground node a the 121GW is.
So it's a system connection error, not a meter error.
The 121GW can display it's own burden voltage (unique feature), but not in power measurement mode. But if you added that burden voltage and added to the voltage on the UT181 you should find that the two reading should match.?
Or of course simply connect the UT181 ground to 121GW ground.
This is why it was spot on at the low voltage, and then got progressively more error as you increased the current.?
Funny, what you are calling an error in my setup, I was calling an error in the calculations. Thanks for jumping in as I did not want to answer oh2hyt because I knew they were correct. I just assumed this was a missing firmware calc.
I was expecting the meter to measure the power at the load and would include the burden voltage as part of that calculation which is why it is connected this way. Yes, if I wanted to measure the power dissipated by the load plus the meter, you are both correct and the three meters read very close. I had tested it up to around 50 Watts (5A 10V sort of range). I have not looked at AC.
So, to be clear this is really what the plan is? Not to display load power by compensating for the burden?
The 121GW can display it's own burden voltage (unique feature), but not in power measurement mode.Sounds really cool feature.
I don't recall when we discussed this way back, but IIRC it wasn't possible to measure the burden voltage in power measurement mode for some reason, hence there was no data to compensate.
You could of course guess and fudge in a number and do it that way, but is guessing better than not including it?
I'll take another look at it though.
The second display can show the volts or amps BTW, just keep pressing SETUP to get to it, yes confusing, need to fix this in the firmware.
I had no idea about being able to read the current/voltage. Just tried it and seems to work. Really, UI is not too bad. Needs a little polish is all.
Also, I'm curious what your thoughts are on the 400mA ASTM fuses. If you have some that are out of a different lot, I would be interested in knowing if their cold resistance changes a fair amount. That 2 ohms I measured seems a bit high.
QuoteAlso, I'm curious what your thoughts are on the 400mA ASTM fuses. If you have some that are out of a different lot, I would be interested in knowing if their cold resistance changes a fair amount. That 2 ohms I measured seems a bit high.I have many boxes of them, will need to do some measurements.
The 121GW can display it's own burden voltage (unique feature), but not in power measurement mode.Sounds really cool feature.
Betting the cold resistance relates in some way to the radial position of a spool of wire that supply the fuse elements before cutting. Looks like there is a slight stretch in the wire with it having some cyclic change in either width of slitting or thickness in the original sheet, and this is carried through to the order in which they were packed in the box with some faithfulness. No other way to get that cyclic curve in resistance with them coming out the box in order.
Anyone else watch bigclive's last video and think it was going to be the end of that CEM meter?
https://www.youtube.com/watch?v=FbAxn5dgoic (https://www.youtube.com/watch?v=FbAxn5dgoic)
Datasheet spec is 1.65. So seems they are specifying the lowest typical measured value, and it can be higher based on contact and wire tolerance etc. But not really lower.
Datasheet spec is 1.65. So seems they are specifying the lowest typical measured value, and it can be higher based on contact and wire tolerance etc. But not really lower.That's interesting. If I look at the 2014 document, they do indeed show 1.65 typical. However, the document I show in the video from 2016 shows 1.5. See attached.
Sorry for the mistake.
I checked our internal spec, the spec of HV620.0.4 had been 1.5-2.2Ohms since 2015, and we had submit to and approved by the DMI manufacturer by that time.
Since the HV620 series fuse sold to DMI manufacturer only, I believe the mistake caused by forgot to updated the public datasheet after approval by DMI manufacturer internally.
Anyway, the fuses we sold to you are correct and the electrical performance meet spec.
Here I attached the updated datasheet with correct resistance value.
[...] I tend to look for the more obvious answers. :-DDWell, that seems to have been the proper thing to do. :-DD Once again I love it when a company returns proper info when asked about some strange behaviour/result. Credits to them!
[...]
Reply from ASTM:QuoteSorry for the mistake.
I checked our internal spec, the spec of HV620.0.4 had been 1.5-2.2Ohms since 2015, and we had submit to and approved by the DMI manufacturer by that time.
Since the HV620 series fuse sold to DMI manufacturer only, I believe the mistake caused by forgot to updated the public datasheet after approval by DMI manufacturer internally.
Anyway, the fuses we sold to you are correct and the electrical performance meet spec.
Here I attached the updated datasheet with correct resistance value.
@EEVBlog: Dave, it'd be good to have the actual interval, instead of 0, output to the file when setting len = 0.
@EEVBlog: Dave, it'd be good to have the actual interval, instead of 0, output to the file when setting len = 0.
I agree. Being a pre-production unit and knowing they are working on the UI, they may have already changed it.
With the right firmware ... this meter looks like a winner!
Who needs a Fluke 87V?
(apart from people who want to get past building security guards)
Hi Joe,
Here is something a little different you should tear down and thoroughly test, the $65 Kill A Watt PS-10 power strip.
It is a normal Kill A Watt with some additional "smarts" built in that appear to be pretty useful for any bench on a budget. Its claims to have a "zero-crossing soft start", settable current limiter, leakage current measurements and a 10-tap output strip for up to 18A is begging your lab to get it the thumbs up. Things I'd like to know are: does it protect as claimed, is it accurate, can it be modded to keep the backlight constantly on.
This has the makings of interesting match between a useful smartie-pants power accessory and the latest word in electrical safety testing!
Joe, just for a lark, can you put a few USB wall warts ( not the cheap ones, but ones from reputable manufacturers, because we all know how the cheap ones will fail anyhow) across your line simulator and see what it takes to kill them. My guess is that almost all of them will fail 2kV, but just how badly they do this, and how much they smoke doing so. Most will probably work fine with your test voltage, being universal input devices. You will just need a sacrificial USB voltage monitor and a resistor to draw 100mA to 500mA out of them during the test. Pretty much how they behave in transient conditions, and what a simple mains transient like a motor disconnect on the same branch circuit will affect them.
What about multimeters crashing when connected to HV, to take a voltage measurement?
I've seen a few where the display flickers or the meter reboots when touching the probe to high voltage.
There is a small arc to the probe with the multimeter's input capacitance and I think the EMI burst is too much. Happens consistently around 400-600VDC up, tiny arc.
Long time ago 2002 Fluke had that problem 177,178,179 and did a recall (https://www.cpsc.gov/Recalls/2002/cpsc-fluke-corp-announce-recall-of-digital-multimeters) over the time to reboot making a dangerous situation. Cheap meters never recover, they just look stoned and read garbage.
Is len = 0 the reason the spreadsheet shows the interval to be zero seconds? :-//
Yes. Setting it to 1, shows 1 second and it seems to record at that rate. I tried 999, interesting is that it must wait the 999 second before recording the first time rather then recording the first sample once logging is started, then waiting.
It's been a long time since I have really done some major damage to a handheld meter.
Nice job Joe. Will you go over your mods once the meter is released?
@Fungus
The working voltage.
@Fungus
The working voltage.
So ... CAT III 1000V is better than CAT IV 600V? :popcorn:
Why would they even bother with CAT IV then?
@Fungus
The working voltage.
So ... CAT III 1000V is better than CAT IV 600V? :popcorn:
Why would they even bother with CAT IV then?
Read carefully the paper ...
(But, reading carrefully that good paper will not increase your posts counter ...)
(And why is there no such thing as "CAT IV 1000V"?)
(And why is there no such thing as "CAT IV 1000V"?)
There is. Bryman has few meters with that rating. Fluke didn't put it in their whitepaper, probably because they don't have one...
CAT IV 1000V is rated for 1000V continuous and 12000V transient... That's your difference...
The 121GW goes back in time.
https://www.youtube.com/watch?v=LMRPe6YaYB4 (https://www.youtube.com/watch?v=LMRPe6YaYB4)
Like I said before, if you don't work on installations directly connected on distribution networks or outside, and you work only in lab, than CAT II is probably enough, as far as overvoltage transient protection is concerned. And if you work with 800V valve amplifiers in your lab, yes, then 1000 CAT II is better than 600V CAT IV....
Result: CAT III 1000V is better than CAT IV 600V. :scared:
for indoor work ... CAT III for outdoor work you need CAT IV
I think a better description is
Cat III is for after the mains fuse board instead of indoor
Cat IV is for before mains fuse board instead of outdoor
What's the physical difference inside the meter?
What's the physical difference inside the meter?Why do you want a difference inside the meter, a 8000V 2ohm transient test qualifies for usage at 1000V indoor (or after the mains breaker) and 600V outdoor (or before the mains breaker).
I don't want a difference, I want to know if there is a difference.
As someone else pointed out, it is to do with the amount of energy available at that point.
ie after the mains fuse board, the fuse should blow and limit the energy
Before the fuse board, you are relying on the substation trips - how many Amps are they going to trip at :o
The closer you work to the grid (working environment as mentioned) the higher the risk of transients and the greater the risk to the meter and user. Meter voltage derating. ;)What's the physical difference inside the meter?Why do you want a difference inside the meter, a 8000V 2ohm transient test qualifies for usage at 1000V indoor (or after the mains breaker) and 600V outdoor (or before the mains breaker).
I don't want a difference, I want to know if there is a difference.
(consensus seems to be "no").
Meter voltage derating. ;)
FWIW The Fluke 189 has 1000 volts Cat 111 rating on the meter itself, no mention of Cat 4..
OMG, I think I've seen 121gw's guts on video... If you still want to keep internals in secret you have to remove the video... and deal with 778 viewers (so far).
The Amprobe 160C does up to 1500V DC and 12kV pulse:
http://www.amprobe.com/amprobe/usen/digital-multimeters/industrial-multimeters-/amp-hd160c.htm?pid=73247 (http://www.amprobe.com/amprobe/usen/digital-multimeters/industrial-multimeters-/amp-hd160c.htm?pid=73247)
OMG, I think I've seen 121gw's guts on video...Good luck reverse engineering it from that.
Fungus, I think if you wanted to figure this out, the place to start is by writing one or more manufactures and seeing what they have to say. Certainly they are the experts.
It should be obvious that the higher the CAT rating, the more energy available. Assuming you would understand why they would derate the meter at higher CAT ratings and you really are just asking if any CAT III rated meter is automatically rated to CAT IV 600 and if not, what is the difference.
Again, turn to the experts but the first thing I would consider (a guess on my part) is that the fuses used would be rated to break a higher energy circuit for CAT IV than CAT III. Maybe for a CAT III environment for example, they use a 1KV AC/DC 10KA rated fuses. For CAT IV 600, they may require 20KA and CAT IV 1000 maybe 30KA. Again, ask the experts. I am just guessing.
How did your relay drop test ever work out? Did you ever buy any and try to get them to change states? I have not heard any more from Gossen but I expect they don't move very fast.
For CAT II, they say less than 10kA typical. CAT III, less than 50kA. CAT IV, much greater than 50kA. Wow, 50kA!! Dave's ASTM 11A fuses are marked 30kA. I wonder if these would be fine for a CAT IV environment.
I have been able to help a small percentage of people understand what was going on.
I have never bought the software and cable for the BM869s. I really have no idea how it would work or if you could use your own software with it.
I have never bought the software and cable for the BM869s. I really have no idea how it would work or if you could use your own software with it.
I have bought the PC interface cable for this meter. The supplied software is OK and does the job. You get a projection of the meter display, a graph, and a saved copy of the history. All the standard things you would expect the software to do.
Unfortunately the interface does not create a virtual comm port, it instead uses an HID interface. Therefore to use your own software you have to create a suitable HID interface driver, which compared to programming a comm port is rather inconvenient and messy. It is something I have started to investigate but have not actually done.
I am rather disappointed that Brymen chose to design the interface cable this way. I would much rather have an RS232 type serial interface that is easy to program and universally accessible by any hardware.
Unfortunately the interface does not create a virtual comm port, it instead uses an HID interface.
but is the HID interface in the meter, or the cable??It's in the cable. When you plug the cable into a USB port it creates an HID device on the host computer.
most meter i.c.'s just stream the lcd segments every time the display is updated.Indeed, this is what the 869s does too.
if some smartass put a microcontroller in the cable to re-format the data, then you could build a different cable.Someone did post here about creating their own cable from scratch. They reverse engineered the optical protocol at the meter and transmitted the data to the computer over a serial interface.
I wonder if they don't have a mechanical switch in there for the leakage. Note the mechanical breaker is still present but I suspect turn off the TRIAC when the current reaches the set point (calling that their programmable breaker).
I did not transient test the killawatt I had but I did have it apart. Cheap, like you would expect for the price.Joe, just for a lark, can you put a few USB wall warts ( not the cheap ones, but ones from reputable manufacturers, because we all know how the cheap ones will fail anyhow) across your line simulator and see what it takes to kill them. My guess is that almost all of them will fail 2kV, but just how badly they do this, and how much they smoke doing so. Most will probably work fine with your test voltage, being universal input devices. You will just need a sacrificial USB voltage monitor and a resistor to draw 100mA to 500mA out of them during the test. Pretty much how they behave in transient conditions, and what a simple mains transient like a motor disconnect on the same branch circuit will affect them.
I would guess they fall under the generic case and are only required to be tested at 1KV line-to-line.
Again, that sub 20J I test with is basically nothing. I don't see it ever causing a meter or other device to explode or put out much for smoke. Really what you would want to do is run these on a real combo generator if you wanted to see something more like the Fluke multimeter videos where they show the cases coming apart. This is nothing close to what I have setup.
True, but you do have a good audience, and it will be a good thing to show that cheap and nasty really is that, even with limited energy. I think the saving grace for most products these days is the thin wire they use, which acts as an impromptu fuse when the thing fails short circuit. As the fuse is often the thing "designed" out by the cost cutters, and the wire is also "value optimised" to be as thin as possible and as low grade copper as possible this probably is the only thing keeping the fire rate down.
Load them with 100mA or less, just basically to get some of the less regulated ones not actually providing a 5v output, as I have seen many that will be 6V with no load and then drop with load. You DC source of 220V will be enough hopefully to provide this 0.1W of power to the DUT, and then the single pulse will easily show how they fail at providing creepage and spike resistance. Load could be basically a LED and a series resistor, and then a 68R resistor to get to around that 100mA, though I would hesitate to connect any meter you like to the secondary side, unless it will survive the full test voltage itself, or you have a big supply of those HF free meters to sacrifice on the secondary.
I think it's important to also understand Joe's tests in context.
The Fluke 87V, the most trusted meter on the market, fails every single one of Joe's tests. According to Joe's tests it's one of the worst meters on the market. Yet I doubt there is a single 87V owner ever who has seen their meter die due to any ESD or pulse overload etc.
I agree.. most of the tests are a worst case scenarios (black swan events). 87v is a standard when it comes to rugged meters but has failed many of Joes tests. In fact Fluke 101 :) has passed more tests then any of the more expensive meters.
For me it's simply a matter of has a meter passed independent safety testing (UL, ETL etc). If so then it's good enough to recommend and use it on anything it's rated for.
Sure, if a meter is failing ESD testing or something that could potentially be common place, then that may be a cause for concern, but even the Fluke 87V has shown no sign of doing that in practice for the 13 years it's been released as the V series, apart from Joe's test.
In fact Fluke 101 :) has passed more tests then any of the more expensive meters.Sorry, I missed responding to this one. Again, the following is right off the spreadsheet:
I think Cliff wiped out an interesting discussion between a YT'er and myself. Basically this person was posting about how there was no value in these tests and how I had ran the Fluke 87V far above it's ratings. When I asked them about it, they responded how the meter was only rated to some KVRMS. I attempted to try and find out how they came to that conclusion and they responded with DC is the same as RMS and because I was just charging up some caps with DC then putting that across the meter, it was DC. I think they believe it is something like randomtronic's Mr Joules. It made no sense that anyone with any sort of electronics or electrical aptitude would come to this conclusion.
I was hoping they would respond but it appears YT'er or Cliff may have pulled the thread. Not a big deal, except I now wonder how many other people think that this is what is going on.
>https://www.youtube.com/watch?v=2q1YRKyM9tU&list=PLyCxHecaZjJxLq-MldJePSMgjsBThu_PCng (https://www.youtube.com/watch?v=2q1YRKyM9tU&list=PLyCxHecaZjJxLq-MldJePSMgjsBThu_PC)
Ah.. For the record, I deleted my first post (re: corona doping in the 121GW) because I was pissed at the (nameless for now) idiot calling you a retard. Clearly, if he had any clue of the kind of work you've done on the channel, he needed his ass kicked - enough said.
Sure, if a meter is failing ESD testing or something that could potentially be common place, then that may be a cause for concern, but even the Fluke 87V has shown no sign of doing that in practice for the 13 years it's been released as the V series, apart from Joe's test.
But again, even Dave suggests that I ran some sort of ESD test on the 87V and it failed. Again, nothing of the sort ever happened.
And above you say the 87V died at 1.5kV, but that's not on your spreadsheet?
joeqsmith, I'm curious about what kind of capacitance/series resistance is behind your transient generator?
I have used Teseq surge generators (http://www.teseq.com/product-categories/surge-generators.php) but man are they a fortune; over $26K USD plus CDN and yearly calibration was few more grand. Just super expensive, so I can see no companies spending this much on equipment for a single test.
I use lower (i.e. 12ohm vs 2ohm 61000-4-5) series resistance until I know the design has a chance.
And above you say the 87V died at 1.5kV, but that's not on your spreadsheet?
Note that there's two Fluke 87s on the spreadsheet.
Sounds like you are confusing my tests with the IEC standards. I recommend you read the FAQ or first few pages of the thread.
This whole thread is very important because it flushes out the unsafe crap on the market.
This whole thread is very important because it flushes out the unsafe crap on the market.
No it doesn't. This thread deals with robustness, not safety.
eg. The Fluke 87V didn't do very well here but nobody would say it's an unsafe meter.
I'm measuring voltage on HV panel and it would be good to know the multimeter has some qualification to even be in that environment, never mind that my life/limb is at risk.
I think the thread has certainly flushed out meters with bogus overvoltage-withstand claims and substandard idiot protection where people could get hurt.
71pages and i dont think anybody mentioned the really important bit yet - the build quality of the supplied leads/probes
i'm more interested in the insulation than the current handling.
the last 2 sets of probes i binned had the outer insulation crack at the strain-relief.
71pages and i dont think anybody mentioned the really important bit yet - the build quality of the supplied leads/probes
flex it a bit and see how it feels, try to scrape it with blunt edges - like a pcb.
ultimately, cut into one to see how many layers of insulation it has, how much actual metal is inside, and what it is - copper, aluminium, copper-coated steel etc.
Safe meaning it has been certified to meet the IEC standards by a third party, not that if you try and eat it, you may choke to death and therefore it's not safe. There is a difference and why we have these standards. But I understand your desire to troll. This I just a bad place for it.
Point taken, but I'm sticking with the cautionary recommendation
Burial sites are stocked with many techs that may have appreciated such a 4 word 'heads up' about their decimated freshly Cal'D meter
that had all the Safety Certified confidence labels on it,
and the big price
This is my last comment and attendance at this post
I will delete the lot asap at earliest convenience
You can't always trust something that is stamped with a "UL" label, either because it may be faked.
For it's age, IMO this is a really nice general purpose meter. I would take it over the 289 if it were still offered. Fluke 87V, the gold standard, HA! This was by far a better meter IMO.
For it's age, IMO this is a really nice general purpose meter. I would take it over the 289 if it were still offered. Fluke 87V, the gold standard, HA! This was by far a better meter IMO.Agreed. In my opinion the only advantage of the 87 V is the smaller size and battery life (but it is AA, so you can just use low self discharge rechargeables). But the 87-series (the 87 IV aka 187 was not really part of that) is much older and the 189 was replaced by the very different (and more fiddly) 189-II/289 within ~10 years of being released. I also believe the 189 was more expensive than the 87 III. So much less will have been sold. Plus Dave never reviewed one or used one in his videos :P.
There was also another series in the mix that frequently gets overlooked and that was the 863, 865 and 867b models, I'm not exactly sure on the time line for this series but I do believe that they may be the true predecessor to the 287/289 models, I have the 189 and 289 and do keep an eye out for a good 867b to complete the line up. I know member Wytnucls did have one and if anyone else here has one is there any chance of a manufacture date confirmation ?.
If you don't mind, please run that test for me on your 189 and let me know if you see the same thing. This one shows revision 015. I find it hard to believe this meter is not plagued with the same problem but this one sure seems to look good.I conducted the tests at 50 Hz since that is my local mains frequency and the 189 is also set to that. I could redo the tests with the 189 set to 60 Hz if that would make any difference.
Generator mVRMS (50 Hz) | F189 reading (mV DC) |
50 | 45.20 |
100 | 45.19 |
200 | 45.41 |
500 | 45.91 |
1000 | 46.76 |
2000 | 48.61 (last digit unstable) |
3000 | 48.32 (last digit unstable) |
4000 | 46.00 (last digit unstable) |
5000 | 37.5 (last digits unstable) |
6000 | 28.7 (last digits unstable) |
7000 | 23.7 (last digits unstable) |
71pages and i dont think anybody mentioned the really important bit yet - the build quality of the supplied leads/probes
May 2016, Page 36, Post 897 starts the discussion if you want to read through it. We are up almost 80 pages which does take us outside of the Dick and Jane reading level. :-DD
If you want to take that on, you are more than welcome to do so. I'm sure there are people who would greatly appreciate your efforts.71pages and i dont think anybody mentioned the really important bit yet - the build quality of the supplied leads/probes
May 2016, Page 36, Post 897 starts the discussion if you want to read through it. We are up almost 80 pages which does take us outside of the Dick and Jane reading level. :-DD
It might be worth putting links to the principal topics in the first post.
It might be worth putting links to the principal topics in the first post.If you want to take that on, you are more than welcome to do so. I'm sure there are people who would greatly appreciate your efforts.
That true. If you or others decide to spend time to research the thread every time someone asks a redundant question, just post a note for the reference and I could keep a running TOC in the first post. It's not a bad idea really.I don't necessarily mean sitting down and doing it but things could be added every time one comes up.It might be worth putting links to the principal topics in the first post.If you want to take that on, you are more than welcome to do so. I'm sure there are people who would greatly appreciate your efforts.
I had just put the signal generator in series with the power supply to DC couple the two. This meter was set to 60Hz and I was testing at 60Hz. Your 189 in the DCmV range seems more on par with what I would normally see. I will attempt to replicate your data to give you some idea how this one behaves. When I looked at it the first time, it seemed pretty good but maybe I screwed something up.I just redid the test with the following changes:
AC mVRMS (60 Hz) | F189 reading (mV DC) |
off | 44.98 |
50 | 44.99 |
100 | 44.99 |
200 | 45.64 |
500 | 45.00 |
1000 | 45.03 |
2000 | 48.78 |
3000 | 56.14 (OL on 50 mV range) |
3500 | 60.30 (OL on 50 mV range) |
DC offset (mV) | F189 reading (mV AC) |
0 | 45.01 |
1000 | 45.02 |
2000 | 45.02 |
5000 | 45.02 |
10000 | 45.02 |
20000 | 45.02 |
30000 | 45.02 |
40000 | 45.02 |
what is it, mylar?
Well, did he get all 15 amps? :-// :-DD
All multimeters have fuses. The properly designed meters have intentionally placed ones. The rest are random. ;D
Woah! Hope your:phew:handpaw was OK.
They had proper thick holsters back then which managed to contain most of the blast, the selector switch and the screen acrylic went west and I ducked to the east, it's funny reading other peoples comments or theories on what may or may not happen during an event such as I described, until you have been there first hand everything else is just speculation.
I wondered the voltage rating on the PTC "03M" seems to be Apr (http://files.rct.ru/pdf/thermistor/ptc_mz31.pdf) MZ31 series. Epcos PTC's are all blue, B59886C012 (https://www.digikey.com/product-detail/en/epcos-tdk/B59886C0120A070/495-3894-ND/651925) is a 500V 12mA part.
Other meters use a GDT but I think these are slow to ionize, and compared to your impulse generator, MOV's maybe fast enough.
Speaking of continuity, as I never owned an "expensive" (I know that's relative to people and purpose) meter myself, how do the DT830's stack up with the higher quality meters?
Speaking of continuity, as I never owned an "expensive" (I know that's relative to people and purpose) meter myself, how do the DT830's stack up with the higher quality meters?
You mean the freebies? They measure OK but they're liable to fail at any moment and I wouldn't put them within 10 yards of a mains socket.
https://www.youtube.com/watch?v=OEoazQ1zuUM (https://www.youtube.com/watch?v=OEoazQ1zuUM)
Do they even have a continuity test? Mine doesn't.
SAFETY INFORMATION
DT830 series multimeter have been designed according to IEC-1010
concerning electronic measuring instruments with a measurement category
(CAT 600V), the max. permitted transient voltage: 2500V, and pollution2.
CAT I-Measurement Category I is for measurements performed on
circuits not directly connected to mains. ( Examples are measurements
on circuits not derived from mains, and specially protected (internal)
MAINS-derived circuits. In the latter case, the transient stresses are
variable; for that reason, its necessary that the transient-withstand
-capability of equipment is made known to the user.).
Don’t use the equipment for measurement within
Measurement Categories II,III and IV.
I did see that video too, you have to be careful with selecting ranges, not just with mains, and not just with this meter.
P.S. This manual http://all-sun.com/manual/Dt830_en.pdf (http://all-sun.com/manual/Dt830_en.pdf) (I'm not sure if anyone ships that manual, just a result of a search for the models) says:QuoteSAFETY INFORMATION
DT830 series multimeter have been designed according to IEC-1010
concerning electronic measuring instruments with a measurement category
(CAT 600V), the max. permitted transient voltage: 2500V, and pollution2.
I did see that video too, you have to be careful with selecting ranges, not just with mains, and not just with this meter.
I don't think you watched it very carefully.
Right after the DT830 exploded he picked up a Fluke which was connected to the same power supply and held it in his hand while moving the range selector to all positions.
The IEC-1010 standard says that the meter must be safe at the maximum rated voltage with the selector in any position.
Any meter where "you have to be careful with selecting ranges" automatically fails that standard.
(ie. They're lying about the DT830 safety rating)
Not a great surprise, I couldn't find after a simple search the important parts of IEC-1010, so I wouldn't know anything about the standard itself.
I don't think you watched it very carefully.
Right after the DT830 exploded he picked up a Fluke which was connected to the same power supply and held it in his hand while moving the range selector to all positions.
Just for kicks I hooked my 121GW up to my 5kV insulation tester yesterday and it survived.
I might do some more testing to see if this can kill other meters.
Don't have a 5kV scope probe to see the waveform though, but assume there will be a small initial energy burst and then clamping down.
FYI:
https://www.youtube.com/watch?v=Wwz_fdU17aQ (https://www.youtube.com/watch?v=Wwz_fdU17aQ)
I should have ran my test at 10V and then looked at the mV as a percent change and really make those numbers look good. But instead, I ran the same test as before. 1mV, highest sensitivity range, -20 to 60C then calculate a TC from that by looking at the change in voltage / change in temp.
Want to know how the pre-production 121GW and Gossen M248B compare against my most stable meter, watch and find out.
Joe, according to picture I was also looking forward to temperature stability test of your new Fluke 189, do you plan to run it some time later?
And, if I may ask, could you also test $19 AN8008, when you have it?
I hope this to be better than Gossen and... ;)
That Gossen has been a disappointment on so many levels. Maybe the M248B Dave has is the pinnacle of meters.
In order to avoid further confusion about the up and coming 121GW, I have removed all but the original video. It seems having pre-production in the title and mentioning that throughout the videos and then explaining that I had even modified it, still did not mean that everyone would understand that this was not a production unit. I assume Dave reviewed the original video of the set and gave me the thumbs up to make it public, so I plan to leave that one.|O
I made an attempt to remove some of my posts detailing my findings with the 121GW as well. I had made measurements of settling times and such for the meter which like the videos could be a source of confusion as well. Obviously, I can't remove everything without everyone's help removing their own comments but it should help.
I am still looking forward to doing a full on review of the released meter. At that stage I will have the same meter everyone else does. So stay tuned for that..
Also, you may have noticed that I did some additional house cleaning. When I was looking at YT, I was tagged several times over copyrights. I had a video I took at the dragstrip of a friend of mind on a really old Triumph dragbike he built. The track had music playing over the loud speaker. Even though, it was only part of the song and it was buried by the noise, it was flagged and the audio was stripped so you could no longer hear the bikes motor. Really sad we have come to this. On the plus side, I don't think there was anything of great loss. I had one video where I had worked with a guy in Australia comparing some free FEA tools with a high end product and we then modeled my one motorcycle's chassis. We then modified the chassis to match the model. It was the first time I ever ran a 1/4 mile in under 8 seconds. I don't just play with meters..
In order to avoid further confusion about the up and coming 121GW, I have removed all but the original video. It seems having pre-production in the title and mentioning that throughout the videos and then explaining that I had even modified it, still did not mean that everyone would understand that this was not a production unit. I assume Dave reviewed the original video of the set and gave me the thumbs up to make it public, so I plan to leave that one.|O
I made an attempt to remove some of my posts detailing my findings with the 121GW as well. I had made measurements of settling times and such for the meter which like the videos could be a source of confusion as well. Obviously, I can't remove everything without everyone's help removing their own comments but it should help.
I am still looking forward to doing a full on review of the released meter. At that stage I will have the same meter everyone else does. So stay tuned for that..
Also, you may have noticed that I did some additional house cleaning. When I was looking at YT, I was tagged several times over copyrights. I had a video I took at the dragstrip of a friend of mind on a really old Triumph dragbike he built. The track had music playing over the loud speaker. Even though, it was only part of the song and it was buried by the noise, it was flagged and the audio was stripped so you could no longer hear the bikes motor. Really sad we have come to this. On the plus side, I don't think there was anything of great loss. I had one video where I had worked with a guy in Australia comparing some free FEA tools with a high end product and we then modeled my one motorcycle's chassis. We then modified the chassis to match the model. It was the first time I ever ran a 1/4 mile in under 8 seconds. I don't just play with meters..
In times like these, just be sure you won't be sued for libel by Fluke and Gossen due to your 87-V and MetraHit results...
|O
In times like these, just be sure you won't be sued for libel by Fluke and Gossen due to your 87-V and MetraHit results...
How is it that a video from a drag strip is flagged because there happened to be some music playing in the background, and yet there are still thousands of full albums you can listen to on YT just by Googling "<album name> full album"? Is that only true for artists who've decided that the "exposure" they get from being available on YT is a net win? Or is it just that the people uploading these videos put a new one up as soon as the old one gets taken down, forcing copyright owners to play whack-a-mole? Granted, I don't recall seeing a whole lot of Top 40 stuff available as full albums on YT, but plenty of fairly well-known bands nonetheless.
Its sad to see us reach that level of greed. I wasn't profiting from these videos and I doubt that any were audio tracks people would rip. In the case of my friends antique dragbike, I could not strip the music. All I can do is remove the video or leave it without sound. Personally, I don't mind sharing some of what I do on YT but at the same time I have wasted a fair amount of time putting the videos up only to pull them down again. May need to rethink this whole YT thing. Getting too old to waste too much time.
Its sad to see us reach that level of greed. I wasn't profiting from these videos and I doubt that any were audio tracks people would rip. In the case of my friends antique dragbike, I could not strip the music. All I can do is remove the video or leave it without sound. Personally, I don't mind sharing some of what I do on YT but at the same time I have wasted a fair amount of time putting the videos up only to pull them down again. May need to rethink this whole YT thing. Getting too old to waste too much time.
I don't think YouTube is the place for video sharing any more. It's too commercialized and too unfriendly to individual content creators. Maybe better to consider Vimeo or Daily Motion?
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And, if I may ask, could you also test $19 AN8008, when you have it?
I hope this to be better than Gossen and... ;)
I also think it would be interesting to see the AN8008's temperature stability.
And if you do get around to testing it, maybe it could be compared with AN8002?
YT is mostly concerned with media companies, thus the problem with the background music. However, it is not hard to believe this is always a possibility with absolutely everything posted on their platform. They do not really answer to any reason when a takedown notice is sent - they shoot first and ask your name later. IIRC Dave discussed this, as well as many other bloggers as the one below:|O
In times like these, just be sure you won't be sued for libel by Fluke and Gossen due to your 87-V and MetraHit results...
I could see them going for YT first and having them close my account. I'm not sure on what grounds other than they don't like the results. It would be better if they spent the resources on making a better product it the goal is to do better in my tests. I can't see screwing the results for anyone.
Had some idiot post a comment in the last video, something to the effect of me burning all my bridges and something about Dave not helping me out in the future. I would guess I had more than 60 hours into the 121GW videos, tracking down parts, repairs, mods and such. I don't charge anything for these videos. I have no intentions to ever turn on ads. I don't even have a patron or ask for money. It's done out of pure interest on my part. In the end, pulling the videos was the right thing to do if it really was causing confusion.Agreed wholeheartedly. The fanboys do not pay your bills nor help you. Of all technical folks around, I suspect that Dave would be the one that would mind the least having a fair and unbalanced review of his product. He knows nothing is perfect and, to actually put a product out of the door, you have to compromise somewhere; that or you never release anything.
Retrospect, I could have ran the meter to the point of not being able to repair it but I would hope that some of the information I provided Dave would help them come up with a better product.
So to the idiot who posted that comment, let me make it clear, I could care less about burning bridges or who sends me what. In the end, it costs me time and money. I will continue to run the tests unbiased, collect the data and present it. If you don't like the results, don't watch.
Despite one issue here and there, I don't think YT is that bad. Also, the fact they give the space free for people with excellent content but not much traffic is an incredible feat.Its sad to see us reach that level of greed. I wasn't profiting from these videos and I doubt that any were audio tracks people would rip. In the case of my friends antique dragbike, I could not strip the music. All I can do is remove the video or leave it without sound. Personally, I don't mind sharing some of what I do on YT but at the same time I have wasted a fair amount of time putting the videos up only to pull them down again. May need to rethink this whole YT thing. Getting too old to waste too much time.
I don't think YouTube is the place for video sharing any more. It's too commercialized and too unfriendly to individual content creators. Maybe better to consider Vimeo or Daily Motion?
I don't think YouTube is the place for video sharing any more. It's too commercialized and too unfriendly to individual content creators. Maybe better to consider Vimeo or Daily Motion?
I don't think YouTube is the place for video sharing any more. It's too commercialized and too unfriendly to individual content creators. Maybe better to consider Vimeo or Daily Motion?
Only a fool would move to another platform from Youtube. If you do then watch your existing audience drop to close to zero, and have almost zero views through search and related videos, absolutely guaranteed.
Businesses may not use Basic or Plus accounts to host videos. If you want to upload commercial videos, you must use Vimeo PRO or Business. Commercial content includes:
Videos promoting or representing a for-profit business or brand
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Videos hosted on behalf of a business (i.e., uploaded to Vimeo and embedded on your company’s website)
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There are exceptions, however! If you are an independent production company, author, artist, or non-profit, you may use any account type (Basic, Plus, PRO, or Business) to showcase your work.
Regarding robustness, now that I am waiting for a rebranded an860b+ and this video is more important for me than before:If the goal is to make something robust and CAT IV rated, yes having more space would make the job easier. It does not mean that a large meter is going to be more robust than a smaller one or meet a higher standard. The UT181A is physically a big meter and died with one strike of the stupid little grill starter. Again, the layout needed some help. Strange as UNI-T makes some of Danaher's products which are certified to meet the EMC standards. The TPI194 is the same, really large but was damaged with the AC line applied. So having all that room does not mean the designers don't have to still do their jobs.
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(I don't remember details so I am watching it again, although it will take a bit).
I wonder, does the larger PCB comparing to the small version make a difference? There's more space, but I don't know if it does provide better clearances.
Joe, excellent video. Interesting to see how the clamps and the thermistor are safe and sound while the meter is on fumes. Perhaps they are protecting the 3V battery? :)In the case of this meter along with the 8002 you are correct. These special designers put the PTC and clamp remain safe and sound behind the rotary switch. The switch has to take the full voltage which obviously it can't. Most of the meters I look, if they even have a clamp, it's located before the switch and limit the voltage to a few KV. Sometimes they design the switch to handle this voltage, sometimes we get a light show.
Oh, I see... It may be the same special designer that did the work on a meter that had the 10A fuse on the V input (I can't recall the model/brand).Joe, excellent video. Interesting to see how the clamps and the thermistor are safe and sound while the meter is on fumes. Perhaps they are protecting the 3V battery? :)In the case of this meter along with the 8002 you are correct. These special designers put the PTC and clamp remain safe and sound behind the rotary switch. The switch has to take the full voltage which obviously it can't. Most of the meters I look, if they even have a clamp, it's located before the switch and limit the voltage to a few KV. Sometimes they design the switch to handle this voltage, sometimes we get a light show.
Oh, I see... It may be the same special designer that did the work on a meter that had the 10A fuse on the V input (I can't recall the model/brand).Joe, excellent video. Interesting to see how the clamps and the thermistor are safe and sound while the meter is on fumes. Perhaps they are protecting the 3V battery? :)In the case of this meter along with the 8002 you are correct. These special designers put the PTC and clamp remain safe and sound behind the rotary switch. The switch has to take the full voltage which obviously it can't. Most of the meters I look, if they even have a clamp, it's located before the switch and limit the voltage to a few KV. Sometimes they design the switch to handle this voltage, sometimes we get a light show.
I do plan to run the thermal testing on these two meters (8002/8) for those of you who asked.
I do plan to run the thermal testing on these two meters (8002/8) for those of you who asked.
And we have no objection to the 80 deg C span ! (as Dave had) ;)
But, I would be interested in how it is with the alleged thermocouples whose influence prevails allegedly (as Dave mentioned) - could possibly someone (maybe even from Metrology section?) explain that in depth and confirm or disprove Joe's results?
Still, there is data of UT181a which does not seem to be affected by that alleged significant thermocouples influence. Could that influence be mittigated by suitable(proper) material of it's input posts in relation to the connecting conductors?
All that could be prevented (IMHO) if Joe had performed these termal testing with input posts shorted, so no different temperature and voltage potentials on the leads.
I would suggest when you comment, consider that meters could range from the free harbor freight to the overprized Gossen. Some meters may not even read into the mV let alone uVs. Test times are a premium. You may not want to invest a week looking at the drift of a free meter.
I would suggest when you comment, consider that meters could range from the free harbor freight to the overprized Gossen. Some meters may not even read into the mV let alone uVs. Test times are a premium. You may not want to invest a week looking at the drift of a free meter.In my opinion testing at the lowest range has several problems (including Seebeck, ignoring gain errors and variation in the lowest possible range). I would suggest picking a single voltage in the 1 V - 10 V range and sticking to this. If interested, you could do multiple points in a range for a single meter at multiple temperatures to study linearity in both the voltage and temperature range, but doing that for dozens of meters is insane in my opinion. One thing I think is important because differences in the 1 V range often seemed in the order of 1 LSD is to indicate the +/- 1 LSD uncertainty. So if one meter went from 1.000 V to 1.000 V, and another went from 1.000 V to 1.001 V, then I would say the first one had 0% +/- 0.1% drift, and the second 0.1% +/- 0.1% drift.
BM235 test went out well, so test was at that time good?
121GW test went out bad, so test is suddenly bad?
I hope I dont get ban for it...
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121GW test went out bad, so test is suddenly bad?
I hope I dont get ban for it...
It is somewhat suspect to me that meters that showed no difference at 1 V suddenly showed large changes at 1 mV.First, thanks for the bit of feedback. I doubt we will see too many people weighing in on this topic.
As for why I did not bring this up before, because I do not regularly watch Joe's videos. I am not that interested in handheld DMMs. I only hang around for the occasional discussion of testing methods ;).
I'm a little lost on what data are you referring to. Which meters?The only data I could quickly find on your channel: the data shown here (https://youtu.be/0ObW8AA42OY?t=92). Sorry if this is outdated data, I could not find it in your spreadsheet or in another easily searchable video. Now that I look at it again, actually none of the meters that perform not very well with the 1 mV tested are in your 1 V data set, so my statement about them performing much worse is not completely true. I guess the most striking difference is the BM869S which performs pretty well in the 1 V tests but mediocre in the 1 mV test.
However, we really want both gain and offset. For gain pick a level that would not OR on any of the meters I have in their mV range. I see no reason to run them through all of the attenuators to see how each resistor effects the gain. I also can't see changing the range switch during the test. Drop the temps to 0-40 to try and assume the drift is somewhat linear. Stay with the two temperatures, so four data points total. Use the same set of cables for all the meters on both leads, keeping everything symmetrical to minimize these errors. We are not looking for nV errors anyway. For presenting the data, I would just keep the raw data. Ignoring the free HF meter, I could use 250mV as a test point for gain. I would stay with the hour dwell times after the chamber reached the set point.I agree with not changing the range switch during the test. I am curious why the mV range. As you say, the divider should not have much of an effect either way. I guess there could be differences in tempco between the two legs of the divider, but that does not really seems worth worrying about and is not feasible testing.
The 121GW is a prototype unit and Dave said his intent was to send one to Joe for him to see how much it took to blow up.
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I did some "temperature measurements" myself (unpublicable - in the car in the sun ;)), and it seemed to me that (IMHO) meters have some internal (software-firmware) compensation for common temperature range (up to about 45 deg C), because meters are very stable in that range.
I consider that as "cheating".
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P.S. LCD displays of the meters do not like hot+sun - do not ask how I know! Fortunately it is almost reversible.
Canadian winters running a DMM even at -20°C the test leads get very hard and brittle, the LCD display fluid starts to freeze up, alkaline batteries crap out too.This.
I think 0°C is the lowest any DMM is good for.
I don't get why the test of Dave's meter is causing such a fuss.
All Joe did was shove some meters in a temperature chamber same as he did with the UT-61E and some others before.
He has always said that Dave's meter is NOT the final version.
Whilst the huge temperature range that Joe used in the tests isn't really the best way to assess the temp co of the meters
it does show how they survive the experience.
3DB
The only data I could quickly find on your channel: the data shown here (https://youtu.be/0ObW8AA42OY?t=92). Sorry if this is outdated data, I could not find it in your spreadsheet or in another easily searchable video. Now that I look at it again, actually none of the meters that perform not very well with the 1 mV tested are in your 1 V data set, so my statement about them performing much worse is not completely true. I guess the most striking difference is the BM869S which performs pretty well in the 1 V tests but mediocre in the 1 mV test.
I agree with not changing the range switch during the test. I am curious why the mV range. As you say, the divider should not have much of an effect either way. I guess there could be differences in tempco between the two legs of the divider, but that does not really seems worth worrying about and is not feasible testing.
So as far as the rest of the front-end and the ADC are concerned, there is pretty much no difference between shorted inputs at the mV range or the 100 V range. Why not pick a range that is less error prone, like the range that includes 1 V? I would also guess that for most users the lowest and highest ranges are the least used, so picking a middle range makes sense. Are you deliberately testing for thermoelectric voltages inside the meters?
I guess if you wanted spectacular videos you would test at 1000 V and see how they deal with condensation :P.
The 121GW is a prototype unit and Dave said his intent was to send one to Joe for him to see how much it took to blow up.It wasn't even for that, it was never meant to be a formal test, it was just for fun because everyone was asking for it, look at the poll in this thread! Also Joe had done one or more videos publicly asking for me to send one, so I (foolishly?) sent one before it was finished.
I'm just saying that these numbers do NOT have real-world practical meaning, as some viewers seem to think.
I assure you, Joe knows that very well, too.. But he is allowed to have a bit of fun in his own private time, and that is what he does.
I just think it's a shame that he seems to have access to real thermal chamber, and is more than qualified to make real, useful thermal characterization for equipment.
So he could do it that way and finally we would be able to see some numbers manufacturers are hiding like snake is hiding legs...
But of course, it is a serious, time consuming project and I understand if he just don't have time to do it. And that is also fine with me..
Anyone who has ever done thermal testing knows it can take a fair amount of time (weeks, months). With the handhelds, even if I wanted to run a complex test, the data would have to be collected manually or possibly using multiple cameras inside the chamber. A lot to invest for some cheap meters. I'll leave that to the next person.I agree, am fully aware of it and I said so.. I understand you don't have time for it...
So we are back to what test could be ran in the shortest time that yields the most useful information. Again, I am open to suggestions and have posted a proposal that Alm has weighed in on. Feel free to do the same.Fair enough, so to be constructive, I agree with alm and as I stated before him, I think it should be done at volts range.. Even 1-2V is much better than millivolts (some would even say thousands times better :-DD). Complication is with the fact that meters can have 1,2,3,4,5,6V ranges. So full scale will be different for each one.
Sorry you feel that way Dave. I would say if anyone was the fool, it was me. There is little I can do at this point beyond not mentioning the meter and pulling down the videos. If you like I can remove the last one as well. Your call.
So we are back to what test could be ran in the shortest time that yields the most useful information. Again, I am open to suggestions and have posted a proposal that Alm has weighed in on. Feel free to do the same.
Fair enough, so to be constructive, I agree with alm and as I stated before him, I think it should be done at volts range.. Even 1-2V is much better than millivolts (some would even say thousands times better :-DD). Complication is with the fact that meters can have 1,2,3,4,5,6V ranges. So full scale will be different for each one.
That can be mitigated by testing at each full range (or close to full range) and calculating and specifying tempco with percentage instead of absolute values..
So you have meters with 4, 5 and 6V range, connect them to 4V and fire away.. Or you can test meters with same ranges together....
But simply testing at 1-2V would be enough to make it much better than testing at millivolts range..
If you are comparing meter tempcos then just a simple delta at two temps (plus room temp) on a fixed DCV range at close to full scale.The question, however, is will there be anything to measure? Even for -10°C to 40°C, the deviation for several meters was down to 1 LSD (i.e. down in quantization noise), see attached frame from Joe's video that I linked to in my previous post. If you limit the temperature range even more, pretty much all meters might score < 1 LSD, which makes the test not very sensitive (mediocre meter in this regard performs the same as an excellent meter).
Meter data sheet specs are typically given for room temp (23degC) +/- 5 degC. So I'd pick 10degC and 40degC as the other temps.
Room temp doesn't really take any extra time as you do it at the start of the thermal test (unless you don't work in a fairly controlled temp office environment like I do).
If you want to save extra time then just chose a temp in one direction from room temp. I'd suggest at least 20degC delta in any case. Positive or negative direction is a coin toss, doesn't really matter.
Saying 60C is not a real world thing is not true, many lift motor rooms here will regularly reach that and higher in summer, as they typically are brick and concrete slab buildings on top with a lovely reflective silver concentrator of the rest of the building cooking the walls all day. Sitting with almost zero cooling aside from air vents typically closed with rodent proofing and roach proofing mesh, and with 10kW of motor heat being dissipated in the room with it as well, and all the brake, controller and shaft heat rising up into there as well. If you are unlucky you get the older ones that are basically a tin shack, walls, roof and with a tin sheet door, basically a solar oven. You go in there and it might be 60C easily, and you work fast and take regular breaks out in the up to 40C cool outside. Your meter should work there though, you will be leaving it there while you go out for the break and the look for some water to drink.
You tend to get the hotter non room temp conditions a lot more than the cold ones, though you can also be working in a cold store with it sitting at -30C as well, though you probably are really only going to be concerned with rough resistance and continuity, and if voltage is present in about the right range in these conditions.
Sorry you feel that way Dave. I would say if anyone was the fool, it was me. There is little I can do at this point beyond not mentioning the meter and pulling down the videos. If you like I can remove the last one as well. Your call.
I never asked you to nor will I ask you to remove any videos. Entirely your call. I sent you an unreleased and unfinished meter and I can't and and don't want to stop you from doing what you want to do with it.
As an aside, I was surprised to see you doing more with it than I thought you wanted it for (i.e. some fun potentially blowing it up). I'm not really a follower of your videos or this thread so had no real idea about the seriousness you take all this stuff.
Sorry if you thought I was sending you a review unit, that wasn't my intention.
Just today some parts have changed again that affect the tempco and stability of the unit.
I should have ran my test at 10V and then looked at the mV as a percent change and really make those numbers look good. But instead, I ran the same test as before. 1mV, highest sensitivity range, -20 to 60C then calculate a TC from that by looking at the change in voltage / change in temp.
Want to know how the pre-production 121GW and Gossen M248B compare against my most stable meter, watch and find out.
Joe, this test is completely invalid. The meter you have is not the current pre-production unit, it's a prototype that does not have the current voltage reference or divider resistors. I mentioned this in the emails to you when I sent it, so I'm not sure why you tested this.
It is most definitely not representative of the final unit.
I'd appreciate if you don't do any more further testing on this unit as it will only confuse people.
Thanks.
The question, however, is will there be anything to measure? Even for -10°C to 40°C, the deviation for several meters was down to 1 LSD (i.e. down in quantization noise), see attached frame from Joe's video that I linked to in my previous post. If you limit the temperature range even more, pretty much all meters might score < 1 LSD, which makes the test not very sensitive (mediocre meter in this regard performs the same as an excellent meter).
is it really that interesting to focus on this detail?For the normal person, I would hope not. But we could say the same thing about the transient testing. Is that interesting to the normal person? I would again say no but it does seem there is a small group of us who are interested in the subject. Maybe myself along with the other subscribers should seek help on a professional level. :-DD
Maybe the conclusion would just be that the temperature coefficient is negligible for many 3.5 digit meters, at least as far as gain error is concerned?
Just to be clear, that statement referred to the x10 chopper amplifier that is used only for the mV ranges. To me it seems that if you want to pick one range, it is more interesting to study the components that are used for all voltage, current and resistance measurements (ADC and voltage reference). I make no claims about being (more) sane.is it really that interesting to focus on this detail?For the normal person, I would hope not. But we could say the same thing about the transient testing. Is that interesting to the normal person? I would again say no but it does seem there is a small group of us who are interested in the subject. Maybe myself along with the other subscribers should seek help on a professional level. :-DD
If only there was something interesting to look at with a volt signal. Seeing a few counts of change is not much fun. Your idea about testing them with condensation is sounding better and better... :-DD
Maybe the two members who asked to see the 8002/8 tested over temp have an opinion on what they would like to see. Feel free to add to the mix.
Am I the only one confused about why a meter that is checked against two higher cost units and deemed to be pretty good, would go through yet another round of mods that effect the temperature performance? My guess is it must have been a side effect from another change and not that they are directly changing the reference circuit or attenuator network for lower drift. It would not make sense.And if I understand it well, your original test (which caused all that fuss) was about "the x10 chopper amplifier that is used only for the mV ranges" :-/O
If only there was something interesting to look at with a volt signal. Seeing a few counts of change is not much fun. Your idea about testing them with condensation is sounding better and better... :-DDI guess the ultimate choice is between interesting and entertaining or accurate :P.
It is a test, it can not be invalid (unless you compare it with manufacturer data - which you are not going to do)The test may not be invalid, but is it testing the meter or the setup? Is it showing differences between meters or small differences in test setups?
And now we get to the root of the problem and why I changed the test method. I can go back to looking at 1V and run at an even less temperature swing but from the little bit I looked at it, I don't think you will learn much from it.
Am I the only one confused about why a meter that is checked against two higher cost units and deemed to be pretty good, would go through yet another round of mods that effect the temperature performance?
Am I the only one confused about why a meter that is checked against two higher cost units and deemed to be pretty good, would go through yet another round of mods that effect the temperature performance?
We missed something on the 50mV range.
Joe, do you have any idea how reproducible the 1 mV tests were? I.e. if you go back the next day and reconnect a meter, will it show the same results? If thermoelectrics indeed play a role, than I would expect a fair variation between runs due to how the cables are run and how temperature gradients across the cables are.
If only there was something interesting to look at with a volt signal. Seeing a few counts of change is not much fun. Your idea about testing them with condensation is sounding better and better... :-DD
Maybe the two members who asked to see the 8002/8 tested over temp have an opinion on what they would like to see. Feel free to add to the mix.
I think I was one of the two, I asked and still I ask you to test AN8008 - but in the original rig!
I'm not convinced that original test is completely invalid - on the contrary!
Even from previous posts is evident, and I agree with that, that test with narrower range of temperatures ( and 1V level) would probably mean "nothing to write home about".
If I were you, I would continue in that original test (-20 Deg C to +60 Deg C and 1mV), and when new 121GW is available to public, then test it too, please.
When UT181a is stable enough, let others be stable too.
It is a test, it can not be invalid (unless you compare it with manufacturer data - which you are not going to do)
Thank you in advance!
I was probably the other (unless there was someone else too). Personally I only cared about how they compare with each other (the meters). It didn't necessarily need to be real world usage. So I'd be fine with any test that can compare meters (i.e. multiple meters being tested under the same conditions), but being a beginner to electronics, I don't have a deep enough understanding to suggest some high quality methodology. I understand that the more points measured, the more valuable the data, but it would be fun to watch either way. It's not data to draw conclusions from (e.g. how much the drift would be at specific setting at specific temperature range), but it still gives an idea on what different meters display under the same or at least very similar working conditions.
But, if most people would find that running these tests is not useful, and especially if you find it needing more time than the benefit, then I will gladly support that choice.
Just for kicks I hooked my 121GW up to my 5kV insulation tester yesterday and it survived.
I might do some more testing to see if this can kill other meters.
Don't have a 5kV scope probe to see the waveform though, but assume there will be a small initial energy burst and then clamping down.
Hard to say much about the post. You may have had the meter connected and in the off position for all I know. Maybe the insulation tester was off or set to 500V. Let's assume you actually programmed the insulation tester for 5KV and you connected between the 121GW's V & Com inputs and checked it with the meter set to every mode and it survived. I still have no idea what insulation tester was used. Looking at the Hioki 3455 it looks like it has a short circuit current of 2mA or less. It may be enough to damage the meter but I would expect the 121GW's front end to clamp that down easily, maybe.
Added. You are aware I had changed out the HFE part. This is one of the weak points of the design. If you wanted to try it with the meter set to Hz with the insulation tester putting out a positive voltage on V/Ohm relative to GND, it may do something. You need to somehow get the insulation tester to put out the voltage with an open, get the 5KV then discharge it across the meter. The capacitor that AC couples the grounds together may be enough to exceed the HFE's absolute maximum supply voltage.
A member here, Scott was playing around with electronic fly swatters and actually damaged a meter with one. TI bought one and tried to damage the UT90A with it. The UNI-T UT90A has had more abuse and damaged more times than any meter I have. They flyswatter did not have enough energy to get the job done. The UT90A's clamp would just load it down. So I added a little external capacitance, let it charge, then discharged that into the meter. None of this is useful data and it's not something that is recorded in my spreadsheet.
The ANENG AN8008. Enjoy.
https://www.youtube.com/watch?v=TSGLA9heboY (https://www.youtube.com/watch?v=TSGLA9heboY)
Does that mean I owe you a meter?
Too bad they dropped the temperature input. Personally, I would have more use for that than the signal generator.
Does that mean I owe you a meter?
I think it's past the statute of limitations for meter testing.
The ANENG AN8008. Enjoy.
https://www.youtube.com/watch?v=TSGLA9heboY (https://www.youtube.com/watch?v=TSGLA9heboY)
Nothing gets past you, well almost nothing. After seeing the meter unable to power up with the 200MHz 3V signal applied, I was concerned it was going to have problems with the ESD but like the 8002, no problems at all.And technically, it did survive the ESD test. :popcorn:Does that mean I owe you a meter?I think it's past the statute of limitations for meter testing.
The ANENG AN8008. Enjoy.Nice slow motion fireworks Joe!
Can you explain why there are two different HZ switch settings on the ZT109, one under the "VOLT" switch selection, and another in its own dedicated HZ switch position? Are they the same or do they show different results? Confused. TKS.
Grear video for the AN8008, Joe! Thanks for sharing. Nothing unexpected, of course, but at least we got an actual run on this.
One detail: be careful with these screeen polishers! They almost revealed your face to the camera, which would be dangerous as the haters can identify you and come to your house with pitchforks and torches - the 7.7% of the voters above, the Dave fanboys pissed at your 121GW tests or the clueless that think you are shoving discharged caps at inputs. :DD
I agree with you and don't think they would go after you: as you always say, it is just data. If any one of them is willing to reproduce the tests then they can feel free to either create their own jig or politely ask you for the design information to faithfully re-create your setup.Grear video for the AN8008, Joe! Thanks for sharing. Nothing unexpected, of course, but at least we got an actual run on this.
One detail: be careful with these screeen polishers! They almost revealed your face to the camera, which would be dangerous as the haters can identify you and come to your house with pitchforks and torches - the 7.7% of the voters above, the Dave fanboys pissed at your 121GW tests or the clueless that think you are shoving discharged caps at inputs. :DD
Glad you enjoyed it. I was surprised when I could not get the meter to power up and that it could not read 10M. For electronics hobby work, I use > 10M often.
I've had videos up in the past of my face. One was a full month of me not shaving for November. It had some music in it so YT flagged it so I pulled it.
The companies may be more upset than the fans. Then again, not much point as anyone could repeat the tests I run. It would be better to focus on making better products if that was their goal. I guess they could attempt to discredit me or the tests I perform but even that seems unproductive. Fans would be better served by contacting the manufactures with what ever concerns they have. There is really nothing I can do from my end to improve a released product. I wonder how Gossen is making out with the Ultra.
Recently, UNI-T contacted me about doing a review of one of their new meters. I was floored and asked them to spend some time looking at specific videos I have made using their products. I'm sure someone in marketing was thinking free advertisement, which it would be but if the meter does poorly, that's a lot of bad publicity. I can't see any benefit for a company to provide me with products unless they are VERY confident that it will do well in the tests and does not have other problems.I can. A company like Uni-T would benefit from an "official" review from you in a few ways:
I agree with you and don't think they would go after you: as you always say, it is just data. If any one of them is willing to reproduce the tests then they can feel free to either create their own jig or politely ask you for the design information to faithfully re-create your setup.
That said, it may take a lot of time to improve a product after it hits the shelves - minimal changes can get past quite quickly as a "rev" update but significant ones may need recert and that on itself is a pain in the rear end. That is very hard to say if Gossen is either doing soul-searching or actually going through the motions to improve their product.
Recently, UNI-T contacted me about doing a review of one of their new meters. I was floored and asked them to spend some time looking at specific videos I have made using their products. I'm sure someone in marketing was thinking free advertisement, which it would be but if the meter does poorly, that's a lot of bad publicity. I can't see any benefit for a company to provide me with products unless they are VERY confident that it will do well in the tests and does not have other problems.I can. A company like Uni-T would benefit from an "official" review from you in a few ways:
- if all is well they get a Joe certified toughness sealTM
- if it goes bad, they get free training for their design engineers and still have a chance to review the design and present you with a tougher unit later on (wouldn't you review an UT181B or C if you could?)
- if it does ok, they can still brag about being better than an 87V
Astonishing, it had no problems going to 80MHz (yes, mega-Hz). Joe Smith's video (see below) suggests it'll go higher, but beyond that frequency the +17dBm (~1.6V) from my RF generator isn't enough for it. Joe doesn't mention the signal level used for his test.In the first video I show the meter reading 201.5MHz. The second meter was almost as good. That was with the generator set to 20dBm. Obviously, I never looked at the loading effects.
That was rather surprising, but shows that you can only predict so much from appearances. Remember, this meter has no MOVs or similar, and just a single PTC for protection.To be clear, there is a clamp after the PTCs. The other leg is protected by the two 5M series resistors. The current input feeds through a two series switches and has a diode from the center node to the common. These are the pads you see arc in Dave's video and the ones that get vaporized in mine.
It took 3kV to damage it slightly, and ~6kV to kill the IC.Not true. The IC was damaged at 3KV.
And when it was hit with some seriously high energy afterwards, the case remained intact - which is really what safety is about (personal protection, not necessarily surviving electrically undamaged).These are the kind of comments that make me cringe. I can't disagree that the OP may very well consider the half cycle simulator seriously high energy. I have stated many times that the energy levels in these generators are quite low compared with the actual IEC standards. I've also talked about how my goal was never to run safety tests. The problem I see with the comment is someone not knowing any better may read this and think the meter is well protected for safety and surly it is not. If you want to see case splitting energy levels, my channel is not the place.
Obviously, this is for low energy electronics work only, but having said that, this meter performed really well in Joe's tests, so in reality it appears to be more rugged than you might assume.I will agree that it is certainly more robust than many of the meters I have tested on my jig. I imagine if the fuse were pulled (from the mA side) the meter would do worse as the switch is breaking down at a very low voltage and that circuit absorbs much of the energy. Removing the fuse, you would increase the gap. Again, breakdowns like this look fine on my little test setup because the energy levels I run at are so low that meters like this and some of the pocket meters actually survive to higher levels that they would with higher energy levels available. The UNI-T UT90A is a great example of how a really bad front end design can act as a clamp and save the sensitive parts. I have tried many times to destroy that meter and because of the limited energy level I test to, it continues to function.
The LCD is one of the best I've seen in terms of contrast and viewing angle.QuoteThis is interesting. When I turned on my second ZT102, the first thing I noticed was how poor the LCD looked. I also noticed that the switch did not feel near as smooth as the first one. I swapped the LCD from the original meter which had no effect so something else has changed. I also took apart both switches and noticed that they had changed the springs. One set are silver, the other copper colored. I saw no other difference.
Time to decide what to do with the Kasuntest ZT102 that I bought to compare against the AN8008. A quick search to see what other had done and I came across this review of the AN8002 which makes reference to my original video.
http://www.markhennessy.co.uk/budget_multimeters/aneng_an8002.htm (http://www.markhennessy.co.uk/budget_multimeters/aneng_an8002.htm)
Time to decide what to do with the Kasuntest ZT102 that I bought to compare against the AN8008. A quick search to see what other had done and I came across this review of the AN8002 which makes reference to my original video.
http://www.markhennessy.co.uk/budget_multimeters/aneng_an8002.htm (http://www.markhennessy.co.uk/budget_multimeters/aneng_an8002.htm)
If it's still in good shape, maybe you might want to have it to compare with a future meter, I'm sure a new AN/ZT/DM will appear sooner or later. Might even look the same.
Someone had asked about adding a MOV to the meter to improve it's robustness.
The Kasuntest ZT102, running against the big dogs now...
The black substance helps prevents sparking over? It might be common knowledge to most here, but I'm curious about how that works.Joe has previously used it in a few repairs and uses the term Corona dope.
Yes, that is the product I use. Make sure you download and read the MSDS (material safety data sheet) for it before you order it.The black substance helps prevents sparking over? It might be common knowledge to most here, but I'm curious about how that works.Joe has previously used it in a few repairs and uses the term Corona dope.
Google finds several similar products, many of which are clear not black and if I'm not mistaken this is what Joe uses:
http://www.newark.com/gc-electronics/10-4702/corona-dope-2-oz-bottle/dp/90H9237 (http://www.newark.com/gc-electronics/10-4702/corona-dope-2-oz-bottle/dp/90H9237)
Yes, that is the product I use. Make sure you download and read the MSDS (material safety data sheet) for it before you order it.The black substance helps prevents sparking over? It might be common knowledge to most here, but I'm curious about how that works.Joe has previously used it in a few repairs and uses the term Corona dope.
Google finds several similar products, many of which are clear not black and if I'm not mistaken this is what Joe uses:
http://www.newark.com/gc-electronics/10-4702/corona-dope-2-oz-bottle/dp/90H9237 (http://www.newark.com/gc-electronics/10-4702/corona-dope-2-oz-bottle/dp/90H9237)
Amazing amount of custom modding. While I understand little of it, still find it entertaining. I would be heartbroken when it failed after all that time and effort, so I appreciate how far you go in your experiments!
It's for science :-+
P.S. I think the big WW power resistor is needed to help the PTC take the hit.
Carbon comp power-resistors are expensive and end-of-life now, drift is terrible.
How many here or anywhere would take a full day to mod a $20 meter, just to test it to failure, for NO financial compensation? You are far too modest, and way UNDERPAID! :)
It's for science :-+
P.S. I think the big WW power resistor is needed to help the PTC take the hit.
The Gossen's gas tubes are fast enough?Three meters I have ran used GDTs. Both this Gossen and HIOKI survived. There was also a Keysight meter that failed at 5KV. Because the Keysight failed with the small generator, it was a candidate for the half cycle generator as well. Not a great test but the added energy gives you some idea how other areas in the meter may fair once we have a breakdown.
The Hioki PCB DT4252 layout- a 1,000V fuse with tiny spacing between the trace and clip.There is no need to guess about the HIKOI. If you look on page 31 of this thread, we spent some time going over it.
I'd expect an arc there after the fuse clears. Sigh. Engineer's screwup telling PCB CAD guy that both sides of a fuse are at the same potential. Not after it blows...
Fuse holders with fuses intended to be replaceable by an OPERATOR shall not permit access to parts which are HAZARDOUS LIVE during fuse replacement.
101.3.2 Protection by a certified overcurrent protection device
If the protection device is a fuse, it is replaced with an open-circuited fuse. ....
A voltage of two times the highest RATED voltage for any TERMINAL is applied to the TERMINALS of the overcurrent-protected measuring circuit for 1 min. The source of the test voltage shall be capable of delivering 500 VA. During and after the test, no damage to the equipment shall occur.
There is no need to guess about the HIKOI. If you look on page 31 of this thread, we spent some time going over it.
Screwdriver drop test!!! :popcorn:There is no need to guess about the HIKOI. If you look on page 31 of this thread, we spent some time going over it.
Link!
Screwdriver drop test!!! :popcorn:There is no need to guess about the HIKOI. If you look on page 31 of this thread, we spent some time going over it.
Link!
UL 61010 certifiers told me spacings must be met around the entire fuse; (not just the end-bells or clips). Why :-// the mid-section is ceramic.
Their answer:
Because you never know exactly where inside a fuse the link has melted i.e middle, left, right- regulatory consider the entire body of the fuse energized to hazardous live, and carbonized (=conductive).
Additionally, spacings surrounding the overcurrent protection device in the equipment and following the protection device in the measuring circuit shall be sufficiently large to prevent arcing after the protection device opens.This is under 101.3.2 and requires the same test as above. This assumes you are using a certified fuse.
So I had to do placement and PCB layout that leaves a large island around the entire fuse. If parts are too close, you see heatshrink covers used.I've shown some meters that were really bad in the fuse area. As long as you are self certified, I guess you can get away with it.
It's too bad a 5x20mm fuse could not be developed with a (DMM) 1kV high-interrupt rating. These DMM fuses are pretty huge.
AN8008 CALIBRATION BASICS
I've figured out how to do calibration although I don't have the finer details worked out. Here's what I know...
1. Short out J1 on the PCB (it's at the top right corner as you look at the PCB from the back of the meter)
2. Get your calibration reference ready and connected - in my case a 300 mA DC feed through the mA/A terminal and Common
3. Turn rotary control from off to the resistance position and CAL will appear on the display
3. Now WAIT until you hear a beep and then move the rotary control to the mA/A position - if you turn the rotary control away from resistance too quickly it doesn't show the values you've selected but moving the rotary switch around corrects that
4. Press [Set/Hold] (orange) button repeatedly until you see DC mA and a value will be displayed
5. Now you should see a value close to what you're providing the meter with, around 300 mA DC in my case
6. Press the [Range] (blue) button (quick press) to range down (but it only does it in 0.1 A increments)
7. Press and hold the [Range] (blue) button (long press) to range up (but it only does it in 0.1 A increments)
8. Press [Set/Hold] (orange) button to move off that setting (I think this is when the cal change just made is saved)
9. Move the rotary switch to off
10. Clear the link on J1 and power back on and test
As far as I can tell, the trick is to set the input to an exact value like 300 mA so you can set that value on the display during cal because you can't adjust the display to 303 mA so, for my slight discrepancy, I saw 298 mA displayed, I ranged down - I saw 200 mA, and then ,with a long press of [Range], ranged up and then I saw 300 mA displayed, pressed the orange button again and I was done. Other parameters can be set by pressing the [Set/Hold] (orange) button repeatedly but you'll only see values corresponding to the rotary position selected so you'd leave it in the resistance position to cycle through the measurements associated with that position including resistance.
What I'm not clear about is when it actually stores a new calibration value, I guess that, once you use the [Range] (blue) button, it changes the calibration for that setting, and I think it saves it when - having got the display to show the value you want, you press the orange button once more.
At first I did my above procedure providing 300 mA but ranged down to display 100 mA and couldn't change that value because I hadn't figured out that a long press ranges up by that point. So when I then switched off and removed the link, it had calibrated the meter to display 100 mA when 300 mA was supplied which it did. I had to re-calibrate after I figured out that the long press increases the displayed value.
After I posted a video where I had modified the KZ102 (AN8002) to the capacitance readings were off about 100pF. Someone had wrote me about modifying the contents of the PROM to realign it. Seems like a lot of work. Does anyone know if the above procedure applies to the AN8002 (and others) as well? For capacitance and current, what are the standard values that are required?
Nice one Joe! This must have been a hell of a lot of work. I actually found this one quite captivating. At one point I stopped it, but changed my mind and watched the entire clip because i was genuinly curious how it would end. Nice to see the meter survives now, did the Hioki not break down in a similar way?
14 KV !! Awesome work Joe. :-+Well, a solid 10KV anyway. You want 14KV, you got it. This was really the goal, get it up to the levels that the most robust handheld meters I have tested survive at. There is not a lot of science to it but I hope that it shows that its not something that is all that difficult to achieve. I really see no reason that especially the $100 and up meters will not survive to the levels this modified $15 Kasuntest meter will.
Very interesting video.
Appreciate the time and effort you give in order to make these videos.
3DB.
AMAZING, originally a $20 meter, guessing after time, parts, and labor, now CUSTOMIZED at over $500!The exercise is not to waist time and money (maybe it's pastime with a purpose?). Joe's channel is the only one I know of that stands up to poor DMM manufacturers by sharing what could have been done but wasn't (for a whole host of reasons).
AMAZING, originally a $20 meter, guessing after time, parts, and labor, now CUSTOMIZED at over $500!The exercise is not to waist time and money (maybe it's pastime with a purpose?). Joe's channel is the only one I know of that stands up to poor DMM manufacturers by sharing what could have been done but wasn't (for a whole host of reasons).
AMAZING, originally a $20 meter, guessing after time, parts, and labor, now CUSTOMIZED at over $500!The exercise is not to waist time and money (maybe it's pastime with a purpose?). Joe's channel is the only one I know of that stands up to poor DMM manufacturers by sharing what could have been done but wasn't (for a whole host of reasons).
You misinterpreted my post, I love the time and effort Joe takes to produce his videos, not sure where he finds the time. My point was there are probably some that would love one of these tiny meters that are customized to such a higher quality degree, but it would cost TOO MUCH in reality. So again, a $20 meter can be "upgraded" to much better grade, but I'm sure Joe would laugh at being able to make any money after his time, labor, and parts, even at $500!
What ever happened with Randomtronics?
True-RMS (calculation) is AC coupled in the DMM IC used in the AN8002, AN8008 etc.
I thought any DC offset is ignored as part of the calculation.
But some DMM's include the DC portion...
True-RMS (calculation) is AC coupled in the DMM IC used in the AN8002, AN8008 etc.Good memory. Yes I did run some tests with DC but maybe not for the reason you suggest. This was really to show the problem with the auto range where the meter shows a low AC voltage. These meters have been the worse I have seen for this. So as long as you are aware of that, you could work around it (add a manual range button as I show).
I thought any DC offset is ignored as part of the calculation.
But some DMM's include the DC portion if using the good old analog AD536 (http://www.analog.com/media/en/technical-documentation/data-sheets/AD536A.pdf) true-RMS converter (which costs much more than a cheap multimeter...)
Joeqsmith, didn't you already try adding a DC offset to a waveform, many posts prior?
Cool mode switch test fixture. Having it running in the background was nice while reading the forum.
I guess this upgrades the thread to, "Handheld meterelectricalrobustness testing."
I had a meter where the switch was bad from the start. Useless. You could not even be sure in what mode you are.
I actually have good experience with the cheapo DT/Harbor Freight type meter (about $2-4 on eBay depending on model or moment). No problems with the switch even with frequent rotation (e.g. turn off after checking, turn on to check again, turn off... to preserve battery - Harbor Freight one has a power switch but eBay China ones do not). But this is different for people who really use their meters (e.g. every single day, for work). They will see switch problems much sooner.
That looks like a really nice rig to test switch duration.
If temperature is an issue with the tests (as in real use it's not likely to get things too heated), is it possible to add some pause after every x rotations?
After your comment about my drop testing and expanding my testing, I was trying to think how to one up it.. lol. Not sure that I will add the switch cycling to my normal tests or not.
Any metallic flakes between the contacts would effect how the meter handles the surge tests. If it's bad enough, I could see it having an effect on the normal operation.After your comment about my drop testing and expanding my testing, I was trying to think how to one up it.. lol. Not sure that I will add the switch cycling to my normal tests or not.
LOL, what will Joe come up with next?
I haven't experienced a bad switch, yet, so it hadn't crossed my mind. However, it does seem to be an issue with some meters. Flaking metallic bits inside the meter could lead to all sorts of bad outcomes. It may be a useful addition to your testing repertoire. At least it's automated so you can do other things as it runs.
Didn't the Kasuntest you originally ran have some kind of lubrication on it? I'm actuaaly quite surprised both meters you tested seem to be near unaffected by so many cycles. I'd be worries about the vias under the wipe contacts, but given the limited wear this probably won't ever be an issue before the meter (or the user) dies. :P
What is it then that you are mentioning here at 9:21 in this video (https://www.youtube.com/watch?time_continue=561&v=HrcxnbkkhYg)? There was definitely something there.Didn't the Kasuntest you originally ran have some kind of lubrication on it? I'm actuaaly quite surprised both meters you tested seem to be near unaffected by so many cycles. I'd be worries about the vias under the wipe contacts, but given the limited wear this probably won't ever be an issue before the meter (or the user) dies. :P
I have bought four ZT102s and one AN8008. None of these had any sort of lubrication that I saw. I have not looked at that last ZT102. I did apply some lubrication to the second ZT102's ball detents, along with swapping out the springs from the first unit to try and get the switch to have a better feel to it. I did the same thing to the third unit.
[...]
What is it then that you are mentioning here at 9:21 in this video (https://www.youtube.com/watch?time_continue=561&v=HrcxnbkkhYg)? There was definitely something there.Didn't the Kasuntest you originally ran have some kind of lubrication on it? I'm actuaaly quite surprised both meters you tested seem to be near unaffected by so many cycles. I'd be worries about the vias under the wipe contacts, but given the limited wear this probably won't ever be an issue before the meter (or the user) dies. :P
I have bought four ZT102s and one AN8008. None of these had any sort of lubrication that I saw. I have not looked at that last ZT102. I did apply some lubrication to the second ZT102's ball detents, along with swapping out the springs from the first unit to try and get the switch to have a better feel to it. I did the same thing to the third unit.
[...]
I have disassembled mine to check for any residue, but I found the board to be completely clean. I did however use the opportunity to put a tad of grease in the detent race. There seems to have been a very minimal amount of it already present, but they supply ball bearings and steel parts that way quite often to prevent corrosion.
well, some people do some extreme things when they have no choice.It seems I read one about a fencer as well but I don't recall the Fluke/UNI-T part. It may have been a whole different case. I imagine this sort of thing happens more frequently than what is ever posted.
i have read of a guy checking the 3KV output of a fence charger he repaired,
first with a fluke - killed it!
then with a low end uni-t that actually gave him the reading!!!!!
another guy testing the neck socket of a crt without knowing how high the focus voltage is.
so low current HV is more "available" than people realise.
Your video actually shown that this dirt-cheap device is at very least conform with CATII/300, means it's compeletely safe to be used in electrical household.
According to spec CATII/300 it should be capable to withstand upto 2500V impulse voltage. Note that It said: impulse, a voltage spike, not a contstant current.
Here's this morning's comment for the day:Living in modern times one can surely tell how people read things diagonally, can't comprehend a text or are simply armchair judges/commentators/etc...QuoteYour video actually shown that this dirt-cheap device is at very least conform with CATII/300, means it's compeletely safe to be used in electrical household.
According to spec CATII/300 it should be capable to withstand upto 2500V impulse voltage. Note that It said: impulse, a voltage spike, not a contstant current.
Why does he feel my tests show the meter is completely safe? People can't read, don't want to take the time to read or they just like to state their opinions no matter if they know something about it or not. I can only guess what that last sentence means. It's too bad these people won't post their opinions in this forum. If you could actually get some constructive dialog (rare), it may actually help the group.
Living in modern times one can surely tell how people read things diagonally, can't comprehend a text or are simply armchair judges/commentators/etc...It works fine if you are living in mom and dads basement playing video games and the height of your week is if you are the first person to comment on a freshly uploaded YT video. :-DD It's pretty rare I will get good constructive criticism that could actually help. Some of the best ones I have gotten were using the HOLD button when comparing meters and fixing the color. :-+
I helped you by bringing you down to planet earth, use a meter within its specs and dont create mythical conditions. Next you will compare it with weather sealed devices? Dont play god, other people have brains too.
Quote... use a meter within its specs and dont create mythical conditions. Next you will compare it with weather sealed devices? Dont play god, other people have brains too.
I assume they believe in a God/s, have a brain but just don't like me creating mythical conditions. Am I the only one who find humor in these posts?
What is it then that you are mentioning here at 9:21 in this video (https://www.youtube.com/watch?time_continue=561&v=HrcxnbkkhYg)? There was definitely something there.Didn't the Kasuntest you originally ran have some kind of lubrication on it? I'm actuaaly quite surprised both meters you tested seem to be near unaffected by so many cycles. I'd be worries about the vias under the wipe contacts, but given the limited wear this probably won't ever be an issue before the meter (or the user) dies. :P
I have bought four ZT102s and one AN8008. None of these had any sort of lubrication that I saw. I have not looked at that last ZT102. I did apply some lubrication to the second ZT102's ball detents, along with swapping out the springs from the first unit to try and get the switch to have a better feel to it. I did the same thing to the third unit.
[...]
I have disassembled mine to check for any residue, but I found the board to be completely clean. I did however use the opportunity to put a tad of grease in the detent race. There seems to have been a very minimal amount of it already present, but they supply ball bearings and steel parts that way quite often to prevent corrosion.
I really don't know what that stuff was. It almost looks like when the board was washed that something dripped down. Normally with grease it will not just wipe off. It smears and it is slick. I've seen a few where they use it and it's always been more translucent and applied around the contacts, not dripped across the board like this one. I have not looked at that 4th unit to see if there was anything in it.
Okay, it was no lubrication then. On film it was difficult to judge (but in your defence: you did say it wiped off easily). It didn't hurt functionality as flux would.I am not sure what would have been the long term effects of it, not knowing what it was. It looked like scum from a wash system and may have had some flux residue in it. It would explain the drip effect. If that's what it was, I could see it causing problems.
I thought I would have a look fore meters that could read engine RPM. I'm sure there are better ones out there.
atdtools.com 5585
INNOVA-3340
PDI PDI 895
Harbor Freight has something
https://www.harborfreight.com/lcd-automotive-multimeter-with-tachometer-kit-95670.html (https://www.harborfreight.com/lcd-automotive-multimeter-with-tachometer-kit-95670.html)
Since this thread has now branched into automotive specific meters, anyone know of any that can be used with one or two cylinders, instead of the usual 3 - 8? I have more of a need for a meter that can read RPM's of single or dual cylinder small engines.Fluke 88 lists an optional inductive pickup that clips around a single spark-plug wire and will measure RPM for a single or multiple cylinder gasoline engine; not good for diesels.
Paul
A few people have been asking me about more specialized handheld meters. One of the most common request I get is for meters with an oscilloscope function.
Since this thread has now branched into automotive specific meters, anyone know of any that can be used with one or two cylinders, instead of the usual 3 - 8? I have more of a need for a meter that can read RPM's of single or dual cylinder small engines.
Paul
wouldnt that just be the frequency function, and multiply the reading by 30 or 60?
If clamping to any spark plug wire
after the distributor, multiply the
displayed reading by the number of
cylinders x 10 to obtain the RPM value.
If clamping to ignition line I or II, multiply
the display reading by 20 to obtain
the actual RPM value of the engine.
Define "cheap". A few of the meters I listed were under $50.
Any idea what features you want, or is your only criteria that it is cheap?Define "cheap". A few of the meters I listed were under $50.Well, under 120euro in EU in a reasonably good condition... Flukes are much more expensive here than in US.
Although, I may not understand what I'm asking, handheld scopes may have isolated inputs which cost a fortune.
these rpm systems are very limited in use btw,
modern cars all use coilpacks, so your meter needs to have a low voltage input for the function.
even a number of pre-coilpack cars used a system of firing a stream of sparks rather than a single discharge, or in the case of alpha-romeo a redundent spark caused by pairing cylinders to a single HT lead.
Any idea what features you want, or is your only criteria that it is cheap?
Any idea what features you want, or is your only criteria that it is cheap?
Sorry, there was misunderstanding from my side. I wanted to know more about "scopemeters". I thought it's a DMM and oscilloscope in one unit. But it looks like it's just a portable oscilloscope, not so much a multimeter. So, I guess, any handheld oscilloscope can be called a "scopemeter".
FEATURES:
ET201 emphasis on functional combination for field testing process, not to replace the meter. It reflects the high-tech, using a dedicated chip has, as the wave function, you can view the waveform signal 10KHZ within. As a large number of measuring instruments Waveform, you will find ET201 is the most affordable one, spend the price of a multimeter, you can have a table can be seen, as the wave of the waveform, value for money!
There's this:
Yeah, looks nice, but only 10kHz? Might as well get one of these:
For $21, DSO150 (https://www.aliexpress.com/item/Fully-Assembled-Orignal-Tech-DS0150-15001K-DSO-SHELL-DSO150-DIY-Digital-Oscilloscope-Kit-With-Housing-case/32826373665.html), nice enclosure, assembled, 200kHz. Pair it with a nice, safe, DMM.
Or for $46, get a DSO-112A (https://www.aliexpress.com/item/DSO-112A-TFT-Mini-Digital-Oscilloscope-Touch-Screen-Portable-USB-Oscilloscope-Interface-2MHz-5Msps/32629013364.html), 2 MHz, 5 Msps.
Joe
How would you feel about doing a tour of your lab and,or your Fluke calibrator ?
3DB
:)
Don't expect me to unbox it and talk about how great it is for an hour.
CEM offers an AT-9996 automotive scope meter. They also have the AT-9995 which is a 4000 count. Tach will work with 2-10 cylinder engines. The dwell supports 2,5,6 & 8 cylinder engines.
....
Of the ones I have seen, I am leaning towards the CEMs and the Brymen. CEM does not appear to have the manuals available.
After seeing the BM235 reset, I am not sure about their automotive products.
Joe, that engine emulator is awesome!Thanks. These little projects are what makes electronics such a fun hobby. There is always so many things to learn. People who are bored with electronics as a hobby must have a really limited skill set.
I suspect the RPM with the Brymens would be limited to 10K in this application.Which isn't of much use if you want to tune a chainsaw. <sigh>
Nice. We've chatted about drags some time back.I shift around 10,500 and go through over 11,000 running 160MPH or so. Not to say that chainsaws are not fun. They most certainly are!!I suspect the RPM with the Brymens would be limited to 10K in this application.Which isn't of much use if you want to tune a chainsaw. <sigh>
There's not much decent available for high RPM engines other than a genuine Husky tacho, but the $$. ::)
http://www.baileysonline.com/Chainsaw-Parts/Repair-Tools/Tachometers-Ammeter/Husqvarna-502-71-14-01-OEM-Pulse-Engine-Tachometer-502711401.axd (http://www.baileysonline.com/Chainsaw-Parts/Repair-Tools/Tachometers-Ammeter/Husqvarna-502-71-14-01-OEM-Pulse-Engine-Tachometer-502711401.axd)
Still, I guess they're are cheaper than these that we used 40 years ago: ::)
http://www.baileysonline.com/Chainsaw-Parts/Repair-Tools/Tachometers-Ammeter/Oregon-Wireless-Tachometer.axd (http://www.baileysonline.com/Chainsaw-Parts/Repair-Tools/Tachometers-Ammeter/Oregon-Wireless-Tachometer.axd)
People who are bored with electronics as a hobby must have a really limited skill set.
I may be a rare breed but I love working far too much to retire. One day that may change.I love that attitude. However, personally I find that when I'm not working I do tend to loose focus on what to do and how to do it and progress gets slower. I respect you for keeping on doing your thing and doing it thoroughly, keep it up! :-+
How bad is the result?
For a cheap meter I do not see it as that bad:
The mA range is usual located so you do not need to pass through it except when measuring A or mA. I.e. it will not see that many passes.
For the other ranges on the meter I would not expect a ohm or two in the range switch is a serious problem.
For the more expensive meters I hope the range switch will lasts considerable longer.
most meters have grease on the switch-pads,
although if that gets contaminated with metal-dust it could maybe create an unexpected path.
There are plenty of other meters around which do not incorporate a rotary selector switch and in turn the necessary lubrication, I'm not sure if you have tested any of these types of meters as yet, maybe you did and I simply missed it. Additionally there are also few other testers and devices about such as CCTV testers and the like which incorporate multimeter features and functionality and from what I have seen they generally do not carry CAT ratings at all, I'm not sure how good the protection is on these types of meters or how they would hold up to scrutiny.
Please explain why you feel that it is necessary to add lubrication to rotary selector switches.I did not at any point state that lubrication was necessary and only referred to meters which incorporate a rotary selector and in turn lubrication which was the context of the prior posts, as you well know there are discussions on which lubricant is best suited for this application and if I remember correctly Fluke themselves recommend a particular product, I don't recall ever having to apply lubricant on any of my meters other than a slight smear of silicone grease to a Fluke 83 which was not working and in a bad way to start with anyway. The question I submitted was entirely in relation to button type meters and their robustness and nothing more than that, sorry if you interpreted my post in the wrong manner.
I am also curious why you feel the vast majority of meters I have looked at do not have lubrication.I made no such suggestion, again with all due respect Joe I think you are reading too much into my post.
I did not at any point state that lubrication was necessary ....
There are plenty of other meters around which do not incorporate a rotary selector switch and in turn the necessary lubrication,...
i was the one mentioning lubrication.I had a ZT102 (AN8002) that had something on the contacts but it did not appear to be a lubrication.
you obviously opened more meters than me, so i assume it was just more common in the past - although there was a very fine layer of lube on an aneng 8002 i recently stripped.
i think it was done in the past to stop the copper contacts oxidising or to prevent tracking in damp enviroments.
these days meters arent expected to have such a long life i suspect.
About the only place I would put a grease of sorts in a multimeter switch is on the detent balls, and the central shaft area, the contacts would probably be best left dry, as they hopefully are a thick selective gold plate running on a selectively plated wiping contact, and this is pretty corrosion resistant in any case. A lubricant on the plastic parts to keep them from wearing each other out is fine, but all switches aside from those designed to run in transformer oil are best left dry.
I made an attempt to change the light to give you a better idea of the wear. The wiper and pads both look really good for 50+ thousand cycles.
It appears that this contact may have started to wear through.
Our first working meter is not holding up very well.
I doubt I will do anything with the environment. Not that it's a bad to look at salt, temp, humidity, thermal shock..... but it would require far more resources than I am willing to commit. It may also be interesting to look at different lubrications, materials, thicknesses... I am not trying to predict MTBF numbers for the designs rather I just want to know how they compare when ran to common set of rules.
To cycle a meter will require a few days and I doubt we will see much of an effect from the changing environment. The plan is to inspect the switch prior to attaching the test points and again after the meter is ran. From this, along with the resistance, we should get a pretty good idea how the various meters compare with one another. I am betting on there being a significant difference in them but again, I don't know.
Like the transient tests, I'm sure we will see all sorts of comments on why the test is invalid when it is all said and done. When the Fluke 101 outperformed the Fluke 87V by a large margin, it brought people out of the woodwork. :-DD
I would welcome seeing more independent destructive tests being ran on handhelds.
what is the test?
fixed number of cycles?
fixed number of hours?
cycle till the switch falls apart? :-DMM
Drift would be a good one to look at. I don't recommend switch cycling. The Kasuntest continues squeaking.
My wife said I can't life cycle the original Fluke 101 I bought because it would be just wrong at this point. :-DD
I am thinking about it. 87V fan boys have been commenting how well these meters hold up over time and question the life of the Brymen BM869s.My wife said I can't life cycle the original Fluke 101 I bought because it would be just wrong at this point. :-DDFWIW I agree. Do the 87V instead.
Anyone want to loan me a brand new 87V to play with for a few days?? :-DD
Anyone want to loan me a brand new 87V to play with for a few days?? :-DDIf it fails, then it's still under warranty, right? After all, the "normal wear and tear" exclusion wouldn't apply because this wear and tear would be anything but "normal", right? :-DD
Your link did not work but item 32818141467 appears to be the UNI-T UT136B. With as many UNI-T products I ran, I have never looked at this one.
I have thought about making a small cooler for my cardboard/foam meat packing box. This will be for fixed temperature testing. I've ran some drift tests for people in the past where I set the box to an elevated temperature and hold it. It would be nice to be able to run a sweep with it. I have not thought about running any sort of controlled shock test. Building some sort of dumbwaiter chamber would take far more effort than I would be willing to invest in a test like this.
Good look testing. As always, it will be interesting to see what you come up with.
The Fluke was the forth meter I have attempted to measure the contact resistance with while life cycling the switch. It has a long road ahead of it but I will say that the preliminary results are impressive. Then again, it's being compared with a free meter, the ZT102/AN8002 and a blown up POS. :-DD
My wife said I can't life cycle the original Fluke 101 I bought because it would be just wrong at this point. :-DD :-DD It has survived everything I have thrown at it but I am still thinking to do some sort of high voltage shootout with the surviving meters at some point. Cycle testing this meter may damage it. 50,000 cycles takes days at the rate I am cycling them takes days, so there is plenty of time to decide.
The second I mostly wanted because it's pink, honestly who wouldn't want a pink multimeter! (Maybe we should all pitch in and buy one for Dave?)
I also love how they can't seem to decide on which batteries the thing uses, or how they show ceramic fuses next to it but never the portion of the PCB that contains said fuse. My money is on glass fuse with a cheap PTC in series. A MOV would certainly cost more than the 5 cents budget they had for the BOM.
The pink would go nice with that florescent green TPI meter I have. Who knows, maybe the pink one will do great compared with the others you look at.
about ut61e drift,
i suspect it was only voltage and related to rough handling.
the older ones had a 2k multi-turn pot, those things can move inside if you bang them hard enough.
the latest ones have a 1k pot and some different fixed resistors so the pot covers a smaller range.
so newer ones should be a lot better.
The Fluke 17B+ has surpassed the free HF meter in cycles and there are no signs of anything going on with the switch. So I think we can hang our hats on the fact that Fluke has a more reliable switch design than the Cen-tech. The first useful bit of info... :-DDIf this little Fluke is able to go to 50k, that would be quite a safe and sturdy meter...
There is still a long way to go before we reach Kasuntest cycles....
My wife is warming up to the idea of running the little 101.If the 101 goes to 50k, that would be an unbeatable price/durability point. :)
Dave recommended that one in one of his videos (at the 1:07 mark):Question is, would this one be banned in Russia?
https://www.youtube.com/watch?v=HicV3Z6XLFA&t=1m07s (https://www.youtube.com/watch?v=HicV3Z6XLFA&t=1m07s)
Maybe he owns one in secret.
Full disclosure: I actually own one, for the stated reason.
Nope, ceramic fuses. Followed by a PTC and some MELF resistors.Mhhh, it'd be interesting to see how it holds up if that's the case. Might have to run it through some careless probing.
Quotegeonomad says:
July 17, 2017 at 3:07 am
The biggest problem I have had with the Chinese cheap meters has been the switch contacts.
If a reading appears wonky, I rotate the selector switch back and forth a few times to “clean”
the contacts and the readings come back to reasonable – sometimes. This is especially true if
the meter has been sitting in a drawer for a long time between uses.
I've been there too... Have you?
Nope, ceramic fuses. Followed by a PTC and some MELF resistors.Mhhh, it'd be interesting to see how it holds up if that's the case. Might have to run it through some careless probing.
Many times as well. A Uni-T UT55 (Triplett 9005) and older analog ones from Icel were always problematic.Quotegeonomad says:
July 17, 2017 at 3:07 am
The biggest problem I have had with the Chinese cheap meters has been the switch contacts.
If a reading appears wonky, I rotate the selector switch back and forth a few times to “clean”
the contacts and the readings come back to reasonable – sometimes. This is especially true if
the meter has been sitting in a drawer for a long time between uses.
I've been there too... Have you?
Yes.
I used to have a manual ranging meter that didn't work on the 20V range* without a bit of switch-jiggling. I eventually threw it out.
(*) ie. The range that gets used the most.
Nope, ceramic fuses. Followed by a PTC and some MELF resistors.Mhhh, it'd be interesting to see how it holds up if that's the case. Might have to run it through some careless probing.
I just dug it out to have a play using my new-found wisdom, gained on these forums.
It's not a great meter compared to this year's wave of ANENGs*, but it IS purple and would fit perfectly into a Hello Kitty themed workbench.
(*) Capacitance only goes down to 1uF, Ohms is slow, diode test can't light up an LED.
Useful results, but I think the argument for durability will depend on some factors.
If you're a professional, by all means you need a reliable durable meter and over time perhaps calibration for some work?
But as a beginner looking to do hobby electronics, unless you use the meter daily I believe even the cen-tech / DT800 series meters will last long enough, switch-wise.
That said, my first meter was about $10 and had issues with the range switch and probe contacts from the start, possibly just a bad unit, or maybe you will find meters that have less durable switches than even the free meter. Another weak point on some meters will be the probe inputs. These will definitely break faster on some meters than others.
Too bad you're not being paid for the tests.
Before anyone beats me, congrats on passing 4K subscribers Joe! I enjoy your dedication sir.
You definitely beat me, Cliff.Thank you for your support. The channel is larger now than I ever expected it to get. I've certainly learned a lot about handheld meters in the process and hope others have as well.
Congrats, Joe! :clap:
Well, again I fully admit I was biased against Fluke from the start. Damn you Fluke for making such robust products....
The Fluke is a very nice meter considering it's age. It actually does get some use on the bench. The Brymen BM869s is still king as far as I am concerned. It's just an all around good meter for electronics. One day I am sure I will find something I like better.Well, again I fully admit I was biased against Fluke from the start. Damn you Fluke for making such robust products....
I think we'll only be sad if your Fluke 189 has displaced your BM869s as your go-to meter on the bench. For me, mainly because the 189 was discontinued shortly before I wanted to get one. So damn you Fluke for discontinuing the best meter you ever made...
The problem I'm still having with the Histograms is that the sum of all the bins, or if you will the area under the curve should be equal the number of samples. So for the Fluke it should be 50 000 also for the Kasuntest and the Baseline, only the CenTech should have a lower total. Since the Fluke has such a low standard deviation it's peak should be much higher to get to the same total of 50 000. Maybe my eyes are deceiving me, and it's just me.
The problem I'm still having with the Histograms is that the sum of all the bins, or if you will the area under the curve should be equal the number of samples. So for the Fluke it should be 50 000 also for the Kasuntest and the Baseline, only the CenTech should have a lower total. Since the Fluke has such a low standard deviation it's peak should be much higher to get to the same total of 50 000. Maybe my eyes are deceiving me, and it's just me.
No problem. I want to try and help you understand what you are looking at. The screen itself has a limited resolution as well. If we continue to push it so the Fluke filled the screen you would see that those bins are pretty narrow and they all have a lot of data in them. This will not be the case with the others. However, part of the problem here may be that you are not actually seeing the bins. I am drawing a line connecting the peak of each bin which can certainly give a different impression.
And for the Log-Log, yes primary issue for me is that you start plotting from 0.005 Ohm, where as that is already the maximum for the Fluke.
But also I wouldn't continue drawing the horizontal line (at least for the Fluke) after 0.005 Ohm, since the Fluke didn't fail at 50 000 Cycles and didn't actually show a change in resistance of 500 Ohm at 50 000 Cycles.
As far as I understand is that you're using the absolute resistance value? If so, than you're not comparing apples with apples. You need to compare the change in value relative to the original start resistance, since the resistance of the tracks/circuits etc of the different meters isn't identical. In software this can easily being done by reading the first value and divide the other readings by the value to get the correct relative value. So this will give you a ratio (or percentage) how much off the meter is after x-amount of cycles.
You understand correct. While we could plot the resistance as a percentage change, I don't feel it is something I "need" to do nor do I see any value in displaying the data this way as it tells me nothing. It could also make a very poor performance switch appear better than it is.
Let's take a simple example using two switches A&B. Switch A has a DCR of 0.001 ohms. Switch B has a DCR of 10 ohm. Switch A say reaches a peak resistance of 0.010 ohms, while switch B reaches a peak of 20 ohms. Switch A has an increase of 10X and switch B, 2X. Looking at a percentage would present Switch B as the better of the two.
You are also correct in there there are other errors outside the switch contacts. For the most part, these will remain a constant throughout the test for a given meter. They make up a small portion of the total resistance. We are basically talking about the trace lengths from the pads to where the wires are attached, the solder joint and the wires going back to the external meter. These wires for the most part are a constant from meter to meter. The same for the solder joint.
...
Anyway, hope some of this helped clear things up. I can certainly understand that how I view the data may not be the way that you or others would want to see it formatted.
...
It's the rotary switch wipers wearing out? I thought the PCB copper would wear out first, it's surely 1oz (1.4mil) or less.
It's the rotary switch wipers wearing out? I thought the PCB copper would wear out first, it's surely 1oz (1.4mil) or less.
Did you ever ask yourself why the bar on an electric train's overhead contact system doesn't wear out in a couple of days?
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=371951;image)
It's the same reason the rotary switch contact does. :popcorn:
Did you ever ask yourself why the bar on an electric train's overhead contact system doesn't wear out in a couple of days?
Did you ever ask yourself why the bar on an electric train's overhead contact system doesn't wear out in a couple of days?
It's the same reason the rotary switch contact does. :popcorn:
Actually, since I am horribly bored in the cleanroom waiting for the vacuum press and laser to do their job, I'll disassemble a DT-830 and put the PCB under the profilometer >:D
That would be an easy test. Let's see what you came up with.
Electric train's pantograph uses carbon strips, (http://www.chemeng.lth.se/ket050/Finalreport2010/Carbonstrip.pdf) softer than copper
One key element is that the overhead wire sweeps from side to side and does not have a single contact patch on the pantograph.
Actually, since I am horribly bored in the cleanroom waiting for the vacuum press and laser to do their job, I'll disassemble a DT-830 and put the PCB under the profilometer >:D
That would be an easy test. Let's see what you came up with.
The contact pressure (force/area) is probably the thing to look at.
Wife says no on this one.:-DD
Wife says no on this one.
Too fast, the models in my day took 9 months!Wife says no on this one.
But delivered in 15-25 working days!
https://www.amazon.com/HJLHYL-MS8233B-Multifunction-Digital-Multimeter/dp/B01MTJMSLZ/ref=sr_1_238?ie=UTF8&qid=1511316372&sr=8-238&keywords=multimeter (https://www.amazon.com/HJLHYL-MS8233B-Multifunction-Digital-Multimeter/dp/B01MTJMSLZ/ref=sr_1_238?ie=UTF8&qid=1511316372&sr=8-238&keywords=multimeter)
Wife says no on this one.
https://www.amazon.com/HJLHYL-MS8233B-Multifunction-Digital-Multimeter/dp/B01MTJMSLZ/ref=sr_1_238?ie=UTF8&qid=1511316372&sr=8-238&keywords=multimeter (https://www.amazon.com/HJLHYL-MS8233B-Multifunction-Digital-Multimeter/dp/B01MTJMSLZ/ref=sr_1_238?ie=UTF8&qid=1511316372&sr=8-238&keywords=multimeter)
Wife says no on this one.
https://www.amazon.com/HJLHYL-MS8233B-Multifunction-Digital-Multimeter/dp/B01MTJMSLZ/ref=sr_1_238?ie=UTF8&qid=1511316372&sr=8-238&keywords=multimeter (https://www.amazon.com/HJLHYL-MS8233B-Multifunction-Digital-Multimeter/dp/B01MTJMSLZ/ref=sr_1_238?ie=UTF8&qid=1511316372&sr=8-238&keywords=multimeter)Women never understand.
Wife says no on this one.
Why would they supply 10 amp leads if it only can do 600ma?
Why would they supply 10 amp leads if it only can do 600ma?
Simple: Because they want the Ohms measurements to be super accurate.
The resistance in probes usual below 0.1ohm each (Down to 0.03ohm for good probes), i.e. it do not have much influence on the ohm range.
Things hide in plain sight :palm: those probes looked familiar (same shorty's that came with my Aneng 8002).The resistance in probes usual below 0.1ohm each (Down to 0.03ohm for good probes), i.e. it do not have much influence on the ohm range.
Not if it was a "600mA" probe. :popcorn:
Things hide in plain sight :palm: those probes looked familiar (same shorty's that came with my Aneng 8002).
Things hide in plain sight :palm: those probes looked familiar (same shorty's that came with my Aneng 8002).
This all seems to be true.Why would they supply 10 amp leads if it only can do 600ma?
Simple: Because they want the Ohms measurements to be super accurate.
How would printing 10A on the probe help with that? Even probes with fairly thin wires has the 10A stamp on them.
The resistance in probes usual below 0.1ohm each (Down to 0.03ohm for good probes), i.e. it do not have much influence on the ohm range.
If you have one, post a few pictures off it along with what model number it is.
I'm not sure I would recommend it to someone, especially if they are able to buy a more expensive unit, but considering the price it is better than I would expect.
Looks like a great tool. What technology/sensor type does it use to detect height/depth of a point?
The switch spring failure in the Keysight is unfortunate. Hopefully, their higher-end meters have a better/more durable mechanism.
Regardless, I imagine folks may be up in arms either (1) complaining about you testing a damaged meter or (2) crying foul trying to devaluate HPAK meters solely based on your overkill usage scenario.IMHO it is good to test stuff until it breaks.The problem is ofcourse that this is just one sample which may be very good or very bad. There is no way to tell other than testing 20 units.
From the graph it seems this one broke after about 6000 cycles.The range selector's wipers aren't related to the switch's clicker mechanics, IMHO, so the graph can't show anything about the clicker.
I would be surprised if the Keysight higher up meters like the U1273A or the U1253B would behave the same way. I have both and so far they seem reliable.
Broken plastic spring is not a problem. Keysight could send you new one made of better plastic.
You are correct in that regard, I didn't think of that that way.Broken plastic spring is not a problem. Keysight could send you new one made of better plastic.
Sure, if you have a local office, a business account with them and the extension number of a support rep.
Good luck if you're in another country or just an individual, eg. Joe couldn't get a reply (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1357096/#msg1357096) out of them.
You are correct in that regard, I didn't think of that that way.Broken plastic spring is not a problem. Keysight could send you new one made of better plastic.Sure, if you have a local office, a business account with them and the extension number of a support rep.
But to be sarcastic, isn't that the reason to pay big bucks to renowned companies, because they don't just sell you products, they give great support...
You are correct in that regard, I didn't think of that that way.Broken plastic spring is not a problem. Keysight could send you new one made of better plastic.Sure, if you have a local office, a business account with them and the extension number of a support rep.
But to be sarcastic, isn't that the reason to pay big bucks to renowned companies, because they don't just sell you products, they give great support...
I'd rather they made good products that don't need any more support than a worldwide speedy-replacement warranty for DOA devices.
Right now the Fluke 17B+ is looking a lot less overpriced than it did a couple of weeks ago.
PS: Maybe Joe could send the meter to 2N3055 and 2N3055 could document the process of getting them to fix/replace it. It's easy, right? :popcorn:
This sort of comment does come up from time to time. Somewhere in this long pile of posts there is a section on it, or you could check the FAQ as I believe I cut and pasted it there as well. I would hope that H-PAK' quality control group has a hand process that is under control but you never know.Regardless, I imagine folks may be up in arms either (1) complaining about you testing a damaged meter or (2) crying foul trying to devaluate HPAK meters solely based on your overkill usage scenario.IMHO it is good to test stuff until it breaks.The problem is ofcourse that this is just one sample which may be very good or very bad. There is no way to tell other than testing 20 units.
From the graph it seems this one broke after about 6000 cycles. You would have gotten over 4 years of life out of it if you turned the switch 5 times a day on every work day.
From the graph it seems this one broke after about 6000 cycles.The range selector's wipers aren't related to the switch's clicker mechanics, IMHO, so the graph can't show anything about the clicker.
The switch is definitely not clicking at all in the intro video (after "a few thousand" cycles).
Joe: You took a photo of the meter at 5000 cycles (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1357096/#msg1357096). Was that before or after recording the intro video? By how much time, approx? That event might give a ballpark clue as to where it failed.
Broken plastic spring is not a problem. Keysight could send you new one made of better plastic. It is the contact damage, board damage and resulting contact resistance that is problem. Board traces are definitely damaged too soon, and that you can't fix easily. It is obvious that PCB integrated switch is not so robust solution in general, and that tested Fluke seem to does it quite nicely and better than the rest of the tested ones..
This is one of those moments when Fluke actually lives up to it's reputation. I'm really curious now as to how Brymen would stand up to this test..
Like Joe, my BM869S is also my favorite meter. I prefer it to others, and actually bought it instead of Fluke 87/V because it was better for my use, not cheaper.
I wonder if maybe switch related problems might be is it's Achilles heel.. Or maybe it stands up to Fluke on that test too?
Would be really interesting to know.
Also, as far as Uni-T goes, I guess 61E would be the one.. Despite not being very electrically robust, it is a good little, inexpensive meter for electronics desk and many people have one and it would be nice to know how long it's gonna last...
Other choice would be 181, that is fully featured meter good for low power electronics work, but it is not that cheap. Would be nice to know how long it's switch would last..
Regards,
Sinisa
I am not sure what problems the spring could actually cause. I run a test where I put a full rectified 220V 60Hz wave into the meters and cycle them through all the functions. The generator detects an over current condition (I think I have it set to 40mA or so) and will shut down to limit any damage. There were several comments about how I was cycling the meters with power applied. Without the spring, the switch will not lock to its centered location. It could even move fairly easily. Could this cause something to happen? I have no idea. Certainly, I could see someone reading a 440 bus having the meter slip off the contacts and start reporting something other than the 440. Could this create a hazardous condition? Keep in mind, this meter has no current input. It uses an external clamp. It's not something you would want as an electronics hobbyist.I wouldn't presume to speculate what electrical damage might happen to the switch and meter because of switch locking between ranges. I was merely pointing out that mechanically, PCB wear was terminal damage to the meter and not the broken spring. If the PCB was not damaged meter would be repairable by just replacing knob. Also I don't think springs being damaged contributed to PCB and contacts excessive wear, and that those two failures should be considered separately, despite being same switch assembly.
What bothers me with some of these meters is all that metallic residue around the switch contacts. I doubt IEC even considers that the meter should be life cycled before running surge. That residue could play into it. For us low energy hobbyist, well for me anyway, the life is more important.I think that is excellent point, especially if there is lubrication on the switch that will retain metallic filings and particles, essentially making it into conductive paste over time...
Your comment about BM869s is true for me as well. The cost really didn't play into it nearly as much as what the product offered. I plan to run at least one Brymen product. It should make for a good video.Agree. Looking forward to it!
I'd rather they made good products that don't need any more support than a worldwide speedy-replacement warranty for DOA devices.
Right now the Fluke 17B+ is looking a lot less overpriced than it did a couple of weeks ago.
PS: Maybe Joe could send the meter to 2N3055 and 2N3055 could document the process of getting them to fix/replace it. It's easy, right? :popcorn:
In case BM869s is damaged out of your transient tests, we will be willing to specially offer free warranty repair or replacement to you.
If you can not repair it, please send it back to us. We will either repair it or replace it by a new one back to you.
I am not a plastics expert but the spring does appear to be made of a glass filled plastic. If the spring would have created some sort of dust, I guess it could contribute to the contacts wear. All the breaks appear clean and I saw only minimal plastic dust and none of it appeared on the circuit board from what I could tell. So I tend to agree.I am not sure what problems the spring could actually cause. I run a test where I put a full rectified 220V 60Hz wave into the meters and cycle them through all the functions. The generator detects an over current condition (I think I have it set to 40mA or so) and will shut down to limit any damage. There were several comments about how I was cycling the meters with power applied. Without the spring, the switch will not lock to its centered location. It could even move fairly easily. Could this cause something to happen? I have no idea. Certainly, I could see someone reading a 440 bus having the meter slip off the contacts and start reporting something other than the 440. Could this create a hazardous condition? Keep in mind, this meter has no current input. It uses an external clamp. It's not something you would want as an electronics hobbyist.I wouldn't presume to speculate what electrical damage might happen to the switch and meter because of switch locking between ranges. I was merely pointing out that mechanically, PCB wear was terminal damage to the meter and not the broken spring. If the PCB was not damaged meter would be repairable by just replacing knob. Also I don't think springs being damaged contributed to PCB and contacts excessive wear, and that those two failures should be considered separately, despite being same switch assembly.
I look forward to your Brymen tests in the future.
I don't want there to be any question in peoples minds about the state of the meter prior to running the test and my BM869s has seen a lot of use since I purchased it. The right thing would be to run a brand new one right out of the box.I look forward to your Brymen tests in the future.
Is the BM869 about to take one for the team? :o
My old Fluke 73/III had a real switch, and a separate spring assembly, that spring assembly had separate part number...
I guess they really don't make them as they used to... :-DD
My old Fluke 73/III had a real switch, and a separate spring assembly, that spring assembly had separate part number...
I guess they really don't make them as they used to... :-DD
I have not seen any imaginary switches used in any of the meters I have looked at. Or at least they appear real to the touch to me anyway. :-DD Sorry... Anyway it looks like someone had posted some decent pictures of what yours looks like. It appears to be a fiber wafer switch similar to what was in the TV sets from my youth. It's too bad we can't get that time machine working or I would put together enough old cash, go back in time and buy some of these brand new and run them. You would think the life would be much longer with the two contact but I have seen a lot of these go intermittent as well. That Tachikawa I recently restored has a separate wafer switch as well. This is not a high end meter by any means.
https://www.eevblog.com/forum/testgear/t21362/ (https://www.eevblog.com/forum/testgear/t21362/)
One of the guidelines in studies of friction in bearings and sliding contacts is that the two mating surfaces should be made of dissimilar materials. In the case of the multimeter switch spring, I would think the plastic springy bit should be made of something hard and durable (maybe like nylon), and the outer ring with the detent slots should be made of something soft and slippery (like polypropylene?).
In the different cases of the meter switch that was durable (Fluke) and the one that wasn't (Keysight) it would be interesting to do a materials analysis of the different components to find similarities and differences. YouTube blogger Ave has often given hints on how to identify different plastics. One simple technique is to find the melting point with a soldering iron set to different temperatures. Sometimes there is even a meterial code embossed on the part.
The bearing surfaces show little signs of wear on the H-PAK. However, once the plastic cracked we lost all the tension which would greatly reduce the wear.
Joe, very informative test as always! However, I think the fact that one of the pads
on the rotary switch was damaged initially fom prior tests you ran, should have negated
this particular meter from your selector switch stress test no matter what you did to
repair/negate the problem. In a real word stress/performance scenario you just can't
bench-test a product and achieve a fair /accurate result if that product was altered
in any way, no matter how good the intentions.
(me)
I was very clear about the damage that had been done to the meter prior to the testing
along with what I had done to mitigate it. If you feel running a brand new unit with
near SNs would change the results, I am perfectly fine with that. I have no data that
shows one way or the other. You are welcome to repeat the test and show your own
results
Indeed Joe. 3rd party Refurbished isnt a factory standard and as such I would take
any testing results with a grain of salt no matter how pretty the graphs might appear.
It's one thing to take a bevy of refurbished meters that had similar issues and produce
a final test result but it's quite another to compare dissimilar meters and try to accrue
some sort "precision" results based on the aftermath of varied component failures.
(me)
I have disclosed if the meters were new, used or had damage to the switch area. I assume
you are considering the repaired meters, like the Fluke a refurbished meter as it was
damaged during the transient tests and repaired by myself (3rd party) . That's fine.
It's only one meter, not really a bevy. If you feel the Fluke would have performed
better (or worse) had Fluke performed the repairs, I am fine with that. It could also
be that a brand new Fluke 17B+ would also perform better than the one I looked at.
Again, I don't have any data one way or the other to suggest different. If you feel
the same model Keysight meter from the same lot would yield different results, you are
certainly free to show your own data. I would welcome it.
I agree with your last comment. Running an FEA on the parts my show something. Then again, it may be more effort than it's worth.The bearing surfaces show little signs of wear on the H-PAK. However, once the plastic cracked we lost all the tension which would greatly reduce the wear.
Yes, I saw the pictures of the crack after I posted. That basically looks like a catastrophic failure. The fact that it failed like that suggests that the mechanical engineers were either absent or failed to do a good enough job on the design.
A recent post from a viewer. To be clear, my goal in posting this here in the forums is to open a discussion about running a test like this. Do you feel all the meters would have to be brand new to gain any understanding about the switched life? Do you feel we need to have different tests for different meters? If so, what do you feel should be the criteria? Do you feel there is no value in running the test because we are only looking at one meter?
Again, to be clear, I am leaning towards running the functional tests, followed by the transient tests just like I always have since I started doing more of a review. After this, I would then life cycle them. If there is anything left, I would then run the half cycle if I thought the meter would give us some sort of light show... :-DD It's obviously a sort of crap shoot with my videos as there are times when I make some pretty big changes to these meters just to try and get a better understanding about their designs.
Feel free to chime in. As far as I am concerned at this stage, there really are no wrong answers.Quote
Joe, very informative test as always! However, I think the fact that one of the pads
on the rotary switch was damaged initially fom prior tests you ran, should have negated
this particular meter from your selector switch stress test no matter what you did to
repair/negate the problem. In a real word stress/performance scenario you just can't
bench-test a product and achieve a fair /accurate result if that product was altered
in any way, no matter how good the intentions.
(me)
I was very clear about the damage that had been done to the meter prior to the testing
along with what I had done to mitigate it. If you feel running a brand new unit with
near SNs would change the results, I am perfectly fine with that. I have no data that
shows one way or the other. You are welcome to repeat the test and show your own
results
Indeed Joe. 3rd party Refurbished isnt a factory standard and as such I would take
any testing results with a grain of salt no matter how pretty the graphs might appear.
It's one thing to take a bevy of refurbished meters that had similar issues and produce
a final test result but it's quite another to compare dissimilar meters and try to accrue
some sort "precision" results based on the aftermath of varied component failures.
(me)
I have disclosed if the meters were new, used or had damage to the switch area. I assume
you are considering the repaired meters, like the Fluke a refurbished meter as it was
damaged during the transient tests and repaired by myself (3rd party) . That's fine.
It's only one meter, not really a bevy. If you feel the Fluke would have performed
better (or worse) had Fluke performed the repairs, I am fine with that. It could also
be that a brand new Fluke 17B+ would also perform better than the one I looked at.
Again, I don't have any data one way or the other to suggest different. If you feel
the same model Keysight meter from the same lot would yield different results, you are
certainly free to show your own data. I would welcome it.
The switch spring failure in the Keysight is unfortunate. Hopefully, their higher-end meters have a better/more durable mechanism.
"Unfortunate" isn't the word I'd use - it's probably not bad luck.
As for "Hope"? I'd want proof. :popcorn:
PS: I wonder if user 'Keysight DanielBogdanoff' reads this thread. Keysight's reputation for multimeters needs some salvage work here. Maybe he could send Joe some meters to test. :popcorn:
When he grabs it and twists the knob it doesn't sound very clicky, not like in your "intro" video.He did say tens of thousands of cycles per year, and two years, I would expect it to be a little less clicky. Maybe he will show you the insides as part of the review he mentioned doing.
Would it kill him to open it and take a look instead of just opining?
Finally managed to get the profilometer long enough to do a scan of a 8x8mm patch near the centre of the switch, but the nickel coating is a bit too reflective it would seem. (It registers as lower than the soldermask :) ) Didn't have time to redo it as a dual scan with two modulation thresholds so here's one to begin with:Thanks for looking at it. You can clearly see the groves. I'll try to scan part of that H-PAK meter. With that wiper contact removed, we should get a pretty good contrast between the pads that were cycled and the ones that were not.
Hopefully. I too agree that he could have shown more of this particular meter, especially because he mentioned having six of these meters and I can't help but wonder if the tens of thousands could be a collective estimate.When he grabs it and twists the knob it doesn't sound very clicky, not like in your "intro" video.He did say tens of thousands of cycles per year, and two years, I would expect it to be a little less clicky. Maybe he will show you the insides as part of the review he mentioned doing.
Would it kill him to open it and take a look instead of just opining?
it doesn't sound very clicky, not like in your "intro" video.He did say tens of thousands of cycles per year, and two years, I would expect it to be a little less clicky.
I'm just wondering what kind of job you have that involves turning the knob on a U1231A every 30 seconds, and why their boss hasn't bothered to optimise their task.
EDIT: Ha, off by an order of magnitude.
I'm just wondering what kind of job you have that involves turning the knob on a U1231A every 30 seconds, and why their boss hasn't bothered to optimise their task.
EDIT: Ha, off by an order of magnitude. But still every 6 minutes seems like a lot.
I'm guessing his numbers are, too. He wasn't exactly rigorous in his video - didn't even take the back off and look.
Mostly he just said "I don't believe it!", I guess that's why he's a boss.
I did ask him to run his own test on the Keysight meter. This one is 2 years old and gets 10s of thousands of cycles yearly.
https://youtu.be/_EQdxZK0yHw
I would guess skeptics will be skeptics no matter the amount of data or how it is presented. Did we fake the moon landings, is the Earth really flat, did man make dinosaur bones and bury them to dig up later.
I see it also many small functional faults add up to big ones, as the 'small' ones show lack of attention to detail particularly in a functional item like choice of transient protection device. By itself it many mean nothing, e.g. the switch failure, but if you look closer you'll see other issues not just in one model, but probably in the whole model line.
Label me as you like but I am a skeptical of using a resistor to evaluate a meters overall performance. :-DDI would guess skeptics will be skeptics no matter the amount of data or how it is presented. Did we fake the moon landings, is the Earth really flat, did man make dinosaur bones and bury them to dig up later.
I could come up with a label for people who believe those things but it wouldn't be "skeptics".
I did ask him to run his own test on the Keysight meter. This one is 2 years old and gets 10s of thousands of cycles yearly.
https://youtu.be/_EQdxZK0yHw
Glad you are enjoying the the videos. I have a fair amount of HP equipment and bought two of their bench meters many years back new. Both of these have never giving me any problems. I would buy another bench meter from Keysight but I don't see running another one of their handheld meters.I did ask him to run his own test on the Keysight meter. This one is 2 years old and gets 10s of thousands of cycles yearly.
Claims you need a process to comment on something yet rambles on without one of his own. In my old uni robotics club there was a 5$ meter that lasted for several years of student (ab)use and international tool box travel. Doesn't exactly make it a great and safe meter. Keysight may have some great products but that doesn't make them s**t gold. To be honest their whole push into the DMM market seems poor considering Fluke is their opponent. The only way to win against them is to give a lot more for the same/less amount of $. More on topic just keep blowing up those meters and play with the remains, for those that want to watch the relevant info is there.
Also Thanks for all the vids :-+
People in general don't like seeing the products that they purchased perform poorly. They need to justify their choices
If you like seeing sparks, I have been working on a new review you may enjoy. So stay tuned.
Most people that have been following along will know I basically test all the meters the same. I suspect he was just new to it all and felt the need to chime in without watching. Funny he felt the need to make a video after I called him out. People in general don't like seeing the products that they purchased perform poorly. They need to justify their choices which I assume is also partly why he made the video. The best part was where he talks about me repairing the meter. That was pure gold. Removing the contact that rides over the damaged area of the circuit board is not what I would consider a repair. I'm pretty sure most people who watch my videos would know that.
Most people that have been following along will know I basically test all the meters the same. I suspect he was just new to it all and felt the need to chime in without watching. Funny he felt the need to make a video after I called him out. People in general don't like seeing the products that they purchased perform poorly. They need to justify their choices which I assume is also partly why he made the video. The best part was where he talks about me repairing the meter. That was pure gold. Removing the contact that rides over the damaged area of the circuit board is not what I would consider a repair. I'm pretty sure most people who watch my videos would know that.
Was that the actual "response" video or is there more to come?
When you mentioned he was working on a "response" video I expected a video with an actual actual response. The one posted here just seemed like a precursor to the real thing.
Say it ain't so.
Maybe the meter tied to a rope pulled behind the boat test or what about the meter tied to a rope and pulled down the stairs or dropped? Now that's entertaining.
Joe, another great video. The only thing going for this meter is the mechanical robustness of the rotary switch. Everything else is pretty terrible... :(
I liked the chemical test at the end.
I watched the three mentioned and the first one was more than enough for me personally. The way they were spouting off, I was really expecting more from them.
I just watched the 'review' video. Lots of talking and reassurances, strangely light on facts.
I did learn a couple of things though:
..........
Overall I'm just perplexed by this video. What exactly was the point of it? He likes his Agilents? :-//
Footnote: I feel slightly bad criticizing. My own videos are far from perfect or in-depth and deeply knowledgeable like Joe's are, he's free to poke fun at them if he wants to (just like Joe does). I wouldn't have said anything except that his video is supposedly aimed directly at this thread.
:palm: I think is very sad to criticize another reviewer.
:palm: I think is very sad to criticize another reviewer. I'm bipartisan. I feel no obliged to camp in any one particular tent. Im grateful others can review hardware no matter how good or bad presentation may be. I did learn more from his video than Joes. JOE is very thorough on teardown and input protection but very lack on meter specifics.We should respect everyone. And if think you can do better than best show.
Me thinks you are wrong. He could have edit the meter setup but chose not to, I prefer that honesty. He demonstrated trigger hold which I had no idea existed with such cheapmeter. I say it again..easy to live in glass house but not if you throww stones. I embrace all reviewers is not easy to do I am sure. :phew:
Me thinks you are wrong. He could have edit the meter setup but chose not to, I prefer that honesty. He demonstrated trigger hold which I had no idea existed with such cheapmeter. I say it again..easy to live in glass house but not if you throww stones. I embrace all reviewers is not easy to do I am sure. :phew:As Fungus have said, the specific videos were done to counteract a claim presented at joe's tests - the lack of a fundamental scientific method reduces the value of their own videos and therefore the criticism is warranted.
There is a possible flaw in joe's testing of the Agilent. The dial may be turning slowly enough not to heat up the PCB but it might be fast enough to build up heat in whatever plastic Agilent is using in their clickers.
...
The only thing the meter appears to have going for it is a cal certificate but he appears to lend far to much weight to that, eg. does the certificate still have any legal weight if the meter falls on the floor? I'm sure Joe could invalidate that certificate in seconds.
I've been thinking about upgrading my home temperature chamber (meat packing box) to include cooling. I had a few old Peltiers from back in the mid 90s. One is about 60mm square. No idea on the brand, part number or specs. Made up a heatsink to try it out. With 10Wish, small sink reaches 12.7C and the large about 38 with the fans off. At 50W and the large fan on, it reached -12 open air. The handheld meters are not much of a load and I have no need to ramp it very quickly. I'll see about mounting it the box and give it a try.
Had some time to waste while the 181A is charging up, so I went ahead and glued the insulation into the upper section. The battery finally died on the Brymen as well. I keep meaning to put a good battery in it but I keep damaging meters so there seems to be an endless supply of cheap batteries. :-DD
Had some time to waste while the 181A is charging up, so I went ahead and glued the insulation into the upper section. The battery finally died on the Brymen as well. I keep meaning to put a good battery in it but I keep damaging meters so there seems to be an endless supply of cheap batteries. :-DD
Yours is probably one of the few labs in which the batteries consistently outlive the meters they came with. :-DD
Had some time to waste while the 181A is charging up, so I went ahead and glued the insulation into the upper section. The battery finally died on the Brymen as well. I keep meaning to put a good battery in it but I keep damaging meters so there seems to be an endless supply of cheap batteries. :-DD
Yours is probably one of the few labs in which the batteries consistently outlive the meters they came with. :-DD
:-DD True. First I've heard of such a problem.
"You could ask Fairchild if they sell the 2N3906 and 2N3906 chips in TO-18. I bet if the military wanted to buy 100 of these for $30 each, they could get them just fine,but, how much AUTHENTICITY do you want to pay for?
Best wishes. / rap"
How did the Brymen perform in the rotary switch testing?
>Quote from: Russ on Today at 02:17:51 AM (https://www.eevblog.com/forum/index.php?topic=48998.msg1379891#msg1379891)How did the Brymen perform in the rotary switch testing?
Patience. If "cycle0" was only 3 hours ago then it's probably not finished yet.
Thanks. I didn’t realize it had just started.
Hmm.., don't know why he'd waste the tracks on his best "go to" meter.. Perhaps Gossen sent him a new Ultra M248C for a Christmas review?
You know the deal, no strings, magnets or shields attached :)
I don't know if you want to look at another Brymen, but the BM315 and BM319 are automotive meters.
Thanks joe, nice to see a manufacturer who is looking to improve the product where it counts. Making sure the stuff will work well after the warranty period, making sure the parts are good value for money, along with making sure it will survive the typical use environment without issues. no wonder we all like those meters and the whole related family of them. Not your typical hit or miss manufacturer, but good value on all the range.
I mentioned I had repaired the Kasuntest and Harbor Freight free DT830 after I had life cycled their switches to save them for future tests. The new ESD gun has never damaged a meter since I started using it. Knowing the grill igniter had damaged a DT830 in the past and the gun puts out a far more realistic waveform, it seemed only fitting to repeat this test. No plans for the Kasuntest yet but I am sure I will come up with something.
Recently there has been some very dry weather in California, and I have noticed that if I walk across the carpet in slippers and then touch something metal I invariably create quite a spark. So what kind of ESD gun am I compared to the fabricated ones? Presumably I am quite a realistic one.
It's time to re-evaluate 121GW :).
That box sure seems big for just two meters. Perhaps there was something else inside....
That box sure seems big for just two meters. Perhaps there was something else inside....
It's time to re-evaluate 121GW :).
Ooh, more goodies!:-+
The anticipation is killing me. Hope this isn't a vicious teaseI'm not well known for not following through. So hang in there for a few weeks or so and you may just see another Brymen on the chopping blocks..
Another item to administer stress to the victims?Don't I have enough instruments of death and destruction already? :-DD
Another item to administer stress to the victims?Don't I have enough instruments of death and destruction already? :-DD
I'm not well known for not following through. So hang in there for a few weeks or so and you may just see another Brymen on the chopping blocks..
Yes, Joe, all ahead FULL.
So much to do with this meter. Brymen did not send them because they knew I would treat them with kid gloves. I think it needs the FULL treatment!Joe correct me if I'm wrong, but something says Bryman's motive is from concern that UEI is soon likely to take a bite out of their sales. I mean what are the odds that UEI may be gearing up to push a lot of 121GW or similar types into the market place this year? And China never sleeps either, so Bryman may be using you (it's fair) to bolster sales on existing stock, while doing R&D on something fresh.
That's an interesting take on it. With as many delays as we have seen for the UEI meter, there is no way I could have projected when it was being released and just happen to be talking with Brymen about their automotive meter and then have them arrive in the same time frame. Perhaps lightages was in on the conspiracy, after all us used to sell Brymen products and he is the one who pointed out they offered an automotive meter. :-DD :-DD Sorry, but I am not buying it or the idea of a flat earth. I doubt the UEI meter is targeted towards automotive and can't see it competing with the one Brymen provided. To be clear, Brymen did not reach out to me and open the dialog nor did they ask me to run the BM869 or even suggest it.So much to do with this meter. Brymen did not send them because they knew I would treat them with kid gloves. I think it needs the FULL treatment!Joe correct me if I'm wrong, but something says Bryman's motive is from concern that UEI is soon likely to take a bite out of their sales. I mean what are the odds that UEI may be gearing up to push a lot of 121GW or similar types into the market place this year? And China never sleeps either, so Bryman may be using you (it's fair) to bolster sales on existing stock, while doing R&D on something fresh.
I checked out the meters they offer. The ADM5201 would have been a good one to try. Both it and the ADM4201 are listed as discontinued at TE. Their ADM3201 is getting a bit too much like that ESUN meter I looked at.Just be warned about the "discontinued" status at TEquipment: not long ago I saw one product still in production that was marked as "discontinued" on their website. I would always check with the manufacturer first.
The ADL7103 is also listed as discontinued at TE. Starting to wonder if they make anything. Maybe the hope is the EEVBLOG branding will save them? :-DD They may just not be popular in the USA, like Brymen.
Just be warned about the "discontinued" status at TEquipment: not long ago I saw one product still in production that was marked as "discontinued" on their website. I would always check with the manufacturer first.
Regarding the Brymen/UEI conspiracy theory, let me throw another one: perhaps they are "using you" to increase their perceived value and be bought by a larger TE brand? :-DD
That is the thing; at the time the product was being sold by other official distributors and TE decided to drop that particular product line or brand. I can't recall if it was the former or the latter, but I kinda recall something about Siglent. Sorry, I don't recall anything further than that.Just be warned about the "discontinued" status at TEquipment: not long ago I saw one product still in production that was marked as "discontinued" on their website. I would always check with the manufacturer first.
Regarding the Brymen/UEI conspiracy theory, let me throw another one: perhaps they are "using you" to increase their perceived value and be bought by a larger TE brand? :-DD
If I can't find a distributor, as far as I am concerned they may as well be discontinued. If TE dropped them, I would have to ask myself why. It could have been anything from lack of sales to poor quality or maybe it really is discontinued. :-//
One should not discount the other possibility.....that a sales distributorship can be revoked and given to another company. This does add confusion to the marketplace for a while especially if the 'no longer' distributor continues to have a web listing for a brand and range of products and lists them as 'discontinued' which is just BS.That is the thing; at the time the product was being sold by other official distributors and TE decided to drop that particular product line or brand. I can't recall if it was the former or the latter, but I kinda recall something about Siglent. Sorry, I don't recall anything further than that.Just be warned about the "discontinued" status at TEquipment: not long ago I saw one product still in production that was marked as "discontinued" on their website. I would always check with the manufacturer first.
Regarding the Brymen/UEI conspiracy theory, let me throw another one: perhaps they are "using you" to increase their perceived value and be bought by a larger TE brand? :-DD
If I can't find a distributor, as far as I am concerned they may as well be discontinued. If TE dropped them, I would have to ask myself why. It could have been anything from lack of sales to poor quality or maybe it really is discontinued. :-//
I doubt the 121GW will be UEI's choice for an automotive meter. UEI already makes an automotive meter that has better features for the Automotive job. They have a whole line of meter just for automotive. UEI already beats Brymen hands down in specific automotive testing and diagnostics tools and lab scopes.
I recall Dave even mentioning that UEI already had a Bluetooth stack and protocol designed that they offered to use with the 121GW, so this tells me they already had a Bluetooth meter.
I don’t know why Dave decided to make his own apps when UEI already had all this to start with? UEI already has an andriod and applemios app. The app looks basic but can do a 100ms refresh rate, record, graph, export to CSV, PNG, or JPG, continuous readings.
http://www.ueitest.com/products/dl429 (http://www.ueitest.com/products/dl429)
Maybe this is why Dave went with UEI this time because he wanted Bluetooth as a feature?
Joe correct me if I'm wrong, but something says Bryman's motive is from concern that UEI is soon likely to take a bite out of their sales. I mean what are the odds that UEI may be gearing up to push a lot of 121GW or similar types into the market place this year?
Who knows under which name they're sold under ... Fine/Finest? Klein?
What about the feature set? Will they be able to incorporate these same functions in another meter lacking the EEVBlog name?
Is this going to be after wiping down those contacts?That's nothing. Think about those two people who have posted how they put 10s of thousands of cycles on their meters every year! In the one case we can be fairly confident that the contacts were never cleaned as they would not take the meter apart to show them in their debunk video. :-DD
At 100 rotations per ~300 working days a year, what tech wouldn't have used some IPA within 16 plus years of use?
I forgot to mark this thread as notify. I’m ised to their boards if you reply to something you automatically get notified. Well, and I miss one email in spam and the notify stops also on this forum.I checked out the meters they offer. The ADM5201 would have been a good one to try. Both it and the ADM4201 are listed as discontinued at TE. Their ADM3201 is getting a bit too much like that ESUN meter I looked at.Just be warned about the "discontinued" status at TEquipment: not long ago I saw one product still in production that was marked as "discontinued" on their website. I would always check with the manufacturer first.
The ADL7103 is also listed as discontinued at TE. Starting to wonder if they make anything. Maybe the hope is the EEVBLOG branding will save them? :-DD They may just not be popular in the USA, like Brymen.
Regarding the Brymen/UEI conspiracy theory, let me throw another one: perhaps they are "using you" to increase their perceived value and be bought by a larger TE brand? :-DD
Yes, that’s the other company I couldn’t remember. It was Siglent I think the sold off remaining stock on eBay and removed from the main site. I don’t know the details, I’m giessing personal conflict disagreement or contractual agreement. Who knows.That is the thing; at the time the product was being sold by other official distributors and TE decided to drop that particular product line or brand. I can't recall if it was the former or the latter, but I kinda recall something about Siglent. Sorry, I don't recall anything further than that.Just be warned about the "discontinued" status at TEquipment: not long ago I saw one product still in production that was marked as "discontinued" on their website. I would always check with the manufacturer first.
Regarding the Brymen/UEI conspiracy theory, let me throw another one: perhaps they are "using you" to increase their perceived value and be bought by a larger TE brand? :-DD
If I can't find a distributor, as far as I am concerned they may as well be discontinued. If TE dropped them, I would have to ask myself why. It could have been anything from lack of sales to poor quality or maybe it really is discontinued. :-//
Crap on a cracker. I was only kidding when I said the 121GW would save them.
I recall Dave even mentioning that UEI already had a Bluetooth stack and protocol designed that they offered to use with the 121GW, so this tells me they already had a Bluetooth meter.
I don't recall ever saying that.
Silly TE never bothers to distinguish between products that are actually discontinued or those that are dropped for arbitrary reasons such as disagreements over marketing, licensing, etc.Just be warned about the "discontinued" status at TEquipment: not long ago I saw one product still in production that was marked as "discontinued" on their website. I would always check with the manufacturer first.If TE dropped them, I would have to ask myself why. It could have been anything from lack of sales to poor quality or maybe it really is discontinued. :-//
Regarding the Brymen/UEI conspiracy theory, let me throw another one: perhaps they are "using you" to increase their perceived value and be bought by a larger TE brand? :-DD
If a product is too difficult to buy, I'm not going to go out of my way to hunt one down.Of course; each to its own. I only found it disingenuous that TE used a term widely adopted in the industry when a product actually ceased to be manufactured. As Dave would say, it was a "dick move".
(...)Thanks for refreshing my memory.
One should not discount the other possibility.....that a sales distributorship can be revoked and given to another company.
(...)
Siglent selling rights were given to Saelig.
I went with UEi because they said they could do a fully custom meter and were keen.
You are right; it would have been strange but not unheard of.It would be strange to find out a company would drop their entire bread and butter product line because they don't want to be in the business only to decided to design and manufacture a custom meter for you. I can just imagine the story behind it. While I previously said they may need saving as a joke, you have adding a new twist.Crap on a cracker. I was only kidding when I said the 121GW would save them.
Who said they need "saving"?
Perhaps they just didn't really want to be in the electronics meter business any more and wanted to focus on other markets?
You are right; it would have been strange but not unheard of.Maybe it's just one person who is leveraging their previous contacts? :-DD Maybe they will contract with Brymen to produce the UEI meter.. :-DD
Actually, looking at their page in the US website, it shows only the model 393 as their active "Digital Multimeter" - all others are discontinued. If one looks only from this angle, it looks like they are more interested to be an ODM or are looking for a comeback to the "electronics DMM segment".
We can only wonder...
Well, at least I know the brand, which is a bit more about the mysterious box than before... :P
Perhaps I missed that post or did not pay attention to a photograph previously posted.Well, at least I know the brand, which is a bit more about the mysterious box than before... :P
The box was shipped directly from Brymen...what other brand was it likely to be?
Joe, I'm sure it is mentioned somewhere earlier in this thread, but what resistance are you measuring during this switch cycling?
I imagined as much, but wanted to be sure I wasn't missing something ;DI wasn't sure if that was what you were asking. So yes, the some of these cheap meter's contact resistance goes well over an ohm in a very short number of cycles. We now know Brymen runs cycle testing but I wonder how many other companies do.
Joe, not that I'm trying to batter with questions here, but do you have criteria for which contact to choose? My hunch on the numbers is that distance from the vertex may affect settling times (say, measuring during a detent sliding contacts into a rest position). I'm confident you're measuring during actuator pauses, but does your sample delay increase if a meters sample point is farther out on the radius?
Also, what have you noticed in general about meters with double contact points (ie: not just resistance, but track wear depth and fragility?)
** Edit: eg: meters similar to this one..
No need. Just have blind faith, Fluke's contacts are certified to hold up during nuclear shock waves! :-DD
The UT210E's added bandwidth was enough to get the video flagged for copyright infringement. The sound quality has improved beyond what the UT90A was capable of. :-DD
If they start to place adds on it, I will most likely remove it.
Can you use some music that doesn't trigger those things? There is "open" music (public domain or creative commons). That is, if you're interested in making such tests in the future, otherwise it really doesn't matter.
I like the big bands and am a bit of a Buddy Rich fan myself. Here with Gene Krupa and Sammy Davis Jr.
https://www.youtube.com/watch?v=NKtoskzi9Pc (https://www.youtube.com/watch?v=NKtoskzi9Pc)
Having a wimpy meter may be alright for some people but not for me. While testing has shown that my favorite meter can take a pretty big hit before it is damaged, it just does not seem right that the cheep little ZT102 / AN8002 can out perform it.Let me guess.. You could call it the yellow wonder. A totally potted Harbor Freight blue-light special?
If you like wimpy meters, this next video is not for you but if you want to see my favorite meter step up it's game, stay tuned. It's 14KV or BUST!!
It's had it's rotary switch cycled 50,000 times, it's swam with the fishes and it has been exposed to transient levels that damaged it's input. Can it survive a 14,000 volt transient with a $1.00 budget and no PCB changes? Watch and find out.
https://youtu.be/u9P4N5HPwf4
$1 in parts and $10 million in engineering later ... :-DD:-DD :-+
$1 in parts and $10 million in engineering later ... :-DDJust finished watching the video. :popcorn:
So what’s the lesson learned from this. Do they need to put better parts...
Joe's just showing off by making it into a 12kV+ meter. :popcorn:Always learning....
(and learning...)
$1 in parts and $10 million in engineering later ... :-DDJust finished watching the video. :popcorn:
Well those transistors are not cheap, maybe a little more then $1 for parts.
So what’s the lesson learned from this. Do they need to put better parts that are equal to or of higher value in front of the PTC’s and what they are rated for? So if the PTC is rated for X then why put transistors that can only handle C in front of them?
That’s one impressive meter for sure, especially with the “Joe Touch” mod. Maybe you should start award levels now? The highest awarded would be to meet or exceed your modified meter testing results, but being stock with no mods or updated parts.
Questions, maybe a dumb one but I’ll ask it anyway.
First, how much can your high voltage scope probe handle, will you need to make a new one if meters start to handle more power then 15KV?
....
Thanks again for all the hard work, great testing and time spent editing and doing these videos.
Maybe now it’s time to take a break. :phew:
Oh, no! You know now that you are mandated by TEA (https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/) law to amend your warning statements, right? "Warning: multimeters AND probes were harmed in the making of this video. TEA viewer discretion is advised."
I remember very well the HV probe discussion as I was interested in making one as well and even got the parts, etc. One thing lead to another and i still didn't find the time to finish this project... :palm:
I was reading through this old thread about the 87V and change in quality and may compare an older 87V with the new one. Maybe there are other differences beyond what was mentioned in the thread.Yes, I remember this thread - a good read after you skim through the trollery. There was some indications of production/material differences but IIRC nothing really conclusive towards declining quality.
https://www.eevblog.com/forum/testgear/fluke-87v-(2017)-lacking-quality-control/200/ (https://www.eevblog.com/forum/testgear/fluke-87v-(2017)-lacking-quality-control/200/)
Read through the FTC documents to see what was involved. It may help explain some of the changes on how they are marked.Thanks for sharing. The FTC does a similar thing as it used to be done in Brazil: assembly must be done in country to be considered "Made in <country>". The issue is that it does not necessarily guarantee the quality of the supply chain, but I personally am pretty sure Fluke would never risk their reputation by skimping on that.
https://www.ftc.gov/tips-advice/business-center/guidance/complying-made-usa-standard (https://www.ftc.gov/tips-advice/business-center/guidance/complying-made-usa-standard)
But I can offer to run another Fluke 87V which was peoples third pick after the Gossen.
We know the 87V I looked at could not come close to the performance of any of the the Chinese made Flukes I have looked. I was asked about the revision of the meter I last ran and it was not the most recent.
What I am thinking is to buy a brand new one, directly from Fluke and repeat all of the transient tests.
Intro.
https://youtu.be/3dxEmi4FGT0?t=817
Has anybody at Fluke shown any interest in your work?
Send them the latest video of the Brymen - the one where you mention that Brymen send you a box of free meters. :popcorn:
I'm sure the rubber shoe on the Fluke 87 will soon "age" to match the color of the kickstand.
The change in certifications seems to have removed the listing at UL - I know that a listed product requires long term commitments regarding quality inspections and other details, which is a continuous stream of negative revenue.
Quite interesting is how the 87V deals with the "hi-res" mode - does that stay enabled after the meter is power cycled? If not, that would greatly detract from a usability standpoint.
Just :horse:, even the UT61E comes with 0.01\$\Omega\$ resolution by default.
Back about 10 posts, I linked the FTC document describing the requirements for the various markings.Yes, but your missing the point about multiple regulation regimes and regulatory risk. Regulations change. Multiply that by how many regulatory regimes (eg, countries) this meter is sold in. Sometimes when they change regulations they do it too fast to clear out all the stock before they come into effect.
I'm missing a point?Back about 10 posts, I linked the FTC document describing the requirements for the various markings.Yes, but your missing the point about multiple regulation regimes and regulatory risk. Regulations change. Multiply that by how many regulatory regimes (eg, countries) this meter is sold in. Sometimes when they change regulations they do it too fast to clear out all the stock before they come into effect.
I am not sure what are the commitments of the UL or UL-CSA marks, but I was referring the UL listing number which requires annual "audits" on the manufacturing facility and design changes and not your typical "fire-and-forget" certification testing of your pre-release / initial production products. This is a long term committment that prevents the product from having its quality erode over time as Extech, for example.The change in certifications seems to have removed the listing at UL - I know that a listed product requires long term commitments regarding quality inspections and other details, which is a continuous stream of negative revenue.
The UL-CSA mark is equivalent to a UL mark. There's no need to have both any more as both agencies can cross certify by agreement. Fluke moved to CSA many years ago for no doubt good reasons which have nothing to do with "long term commitments regarding quality."
Too bad. My previously owned 179 did not have sticky settings as well and it was quite expensive, although it seemed to be tailored to a different market.Quite interesting is how the 87V deals with the "hi-res" mode - does that stay enabled after the meter is power cycled? If not, that would greatly detract from a usability standpoint.
Just :horse:, even the UT61E comes with 0.01\$\Omega\$ resolution by default.
No, the old Fluke meter has no sticky settings like Brymens. IMO, the meter should have an auto mode for that high res. I doubt many electricians have a need for that feature. I can't see too many hobbyist wanting it but then again, if you were driven by marketing, maybe.
I think the only two meters I looked at that can resolve 1mohm are the Gossen and TPI. I can't really count the UEI meter. If the Gossen did not have so many problems, it would be a very nice meter. I wonder if they ever did anything with it or decided it was not worth going after.
If that is true, what is unique? Heck, even the UT61E claims >3G\$\Omega\$ input impedance in mV ranges... My Racal Dana measures the UT61E as having 52M\$\Omega\$, but I suspect this may be wrong as clamping may be influencing it (it puts out a couple of V)
If that is true, what is unique? Heck, even the UT61E claims >3G\$\Omega\$ input impedance in mV ranges... My Racal Dana measures the UT61E as having 52M\$\Omega\$, but I suspect this may be wrong as clamping may be influencing it (it puts out a couple of V)
I am not sure why the 121GW was so low. It could very well be because of my mods. Then again, I damaged that meter a few times as well. Someone else really needs to check it.
I am not sure why the 121GW was so low. It could very well be because of my mods. Then again, I damaged that meter a few times as well. Someone else really needs to check it.
I suppose you are going to check it again when you get the production version. I am also going to check it and do my usual multimeter review of it.
I suppose the timing estimate now is late March.
Many of the meters I have including the Brymen BM869s, Fluke 196, Gossen M248B, UNI-T UT181A are 10 or 11Meg. Even the free harbor freight meter was close to 10M. A few meters were 5M. I found one that was lower than the pre-production 121GW. The YX-360TR. Again, highly modified after being damaged. This meter measures close to 2Kohms in the DC 100mV range.That is a novelty. All M830B clones I have seen have 1M\$\Omega\$ of input impedance in all DC ranges. They even mention this in their manuals.
Many of the meters I have including the Brymen BM869s, Fluke 196, Gossen M248B, UNI-T UT181A are 10 or 11Meg. Even the free harbor freight meter was close to 10M. A few meters were 5M. I found one that was lower than the pre-production 121GW. The YX-360TR. Again, highly modified after being damaged. This meter measures close to 2Kohms in the DC 100mV range.That is a novelty. All M830B clones I have seen have 1M\$\Omega\$ of input impedance in all DC ranges. They even mention this in their manuals.
Do a search some time of the 87V to see what problems people have had with this pinnacle of meters and you may be amazed. I wanted to see if anyone else had performed some sort of AC line test, intentional or not. I think I have my answer:
https://www.eevblog.com/forum/testgear/fixing-a-fluke-87v/ (https://www.eevblog.com/forum/testgear/fixing-a-fluke-87v/)
Exactly what I was thinking. Can it really be this bad? I was going to run the tests just for completeness but now I wonder if it is not even going to make it to the transient tests.
If a MOV rated (loose definition of "rated" here) for 1kV is subjected to, say, 1.2kV, it will try to clamp this voltage differential using the only means it knows: by dissipating the surplus energy through its body. But that you already know.MOVs would give up if limiar overvoltage is applied for too long - the circuitry could probably withstand 1.1~1.2kV, but the MOVs would suffer thermal stress. All in all, I don't think any meter would be too different in this regard (unless they used higher voltage MOVs).
I've had people suggest similar things but it really makes no sense to me. Maybe you could explain why you feel this way. What is causing all of this thermal stress you mention?
Because I am currently looking at the 87V, let's just use it for an example. A few things to consider. The one MOV has a 1Meg resistor in series with it. Even with 2KV applied, will limit the current to 2mA assuming the MOVs were shorted. The second leg uses a PTC and surge rated resistor for the drive side. With enough DC the PTC would eventually kick in but may not limit the current enough to prevent long term damage (assuming the secondary clamp is not engaged). However...If a MOV rated (loose definition of "rated" here) for 1kV is subjected to, say, 1.2kV, it will try to clamp this voltage differential using the only means it knows: by dissipating the surplus energy through its body. But that you already know.MOVs would give up if limiar overvoltage is applied for too long - the circuitry could probably withstand 1.1~1.2kV, but the MOVs would suffer thermal stress. All in all, I don't think any meter would be too different in this regard (unless they used higher voltage MOVs).
I've had people suggest similar things but it really makes no sense to me. Maybe you could explain why you feel this way. What is causing all of this thermal stress you mention?
In the scenario above, considering the output impedance of the source is low enough, the amount of the surplus energy that needs to be dissipated depends on the waveform. In a single pulse transient, the extra energy is perfectly contained with minor (if at all) stress to the MOV. On the other hand, a 1.2kVAC at 50 or 60 Hz will demand the MOV to continuously dissipate the energy contained in the upper and lower cycles of the sinewave. By the same logic and what was reported in the thread I mentioned, 1.2kVDC is the worst scenario as there is no time for the MOV to cool.
In the AC scenario (and to a much lesser extent to DC), the survivabilty of the MOV is highly dependent on its physical characteristics, as well as its environmental (temperature and humidity) and the surrounding heatsink ability of its PCB (large copper areas, clearance, etc.). That is why I mentioned that most (if not all) DMMs would have the same outcome as reported in the linked thread.
That sums it up. I should have prefaced my post with the assumption the MOVs are directly in parallel with the inputs - in other words, I was completely illiterate about the 87V's input circuitry. :)Because I am currently looking at the 87V, let's just use it for an example. A few things to consider. The one MOV has a 1Meg resistor in series with it. Even with 2KV applied, will limit the current to 2mA assuming the MOVs were shorted. The second leg uses a PTC and surge rated resistor for the drive side. With enough DC the PTC would eventually kick in but may not limit the current enough to prevent long term damage (assuming the secondary clamp is not engaged). However...If a MOV rated (loose definition of "rated" here) for 1kV is subjected to, say, 1.2kV, it will try to clamp this voltage differential using the only means it knows: by dissipating the surplus energy through its body. But that you already know.MOVs would give up if limiar overvoltage is applied for too long - the circuitry could probably withstand 1.1~1.2kV, but the MOVs would suffer thermal stress. All in all, I don't think any meter would be too different in this regard (unless they used higher voltage MOVs).
I've had people suggest similar things but it really makes no sense to me. Maybe you could explain why you feel this way. What is causing all of this thermal stress you mention?
In the scenario above, considering the output impedance of the source is low enough, the amount of the surplus energy that needs to be dissipated depends on the waveform. In a single pulse transient, the extra energy is perfectly contained with minor (if at all) stress to the MOV. On the other hand, a 1.2kVAC at 50 or 60 Hz will demand the MOV to continuously dissipate the energy contained in the upper and lower cycles of the sinewave. By the same logic and what was reported in the thread I mentioned, 1.2kVDC is the worst scenario as there is no time for the MOV to cool.
In the AC scenario (and to a much lesser extent to DC), the survivabilty of the MOV is highly dependent on its physical characteristics, as well as its environmental (temperature and humidity) and the surrounding heatsink ability of its PCB (large copper areas, clearance, etc.). That is why I mentioned that most (if not all) DMMs would have the same outcome as reported in the linked thread.
Assuming there is anything left of the 87V when I am done with it, I would be willing to attach it to a 1.2KVDC power supply and let it sit for a long term test. Say a week with the meter in the DC volts setting.That would be an interesting test.
That sums it up. I should have prefaced my post with the assumption the MOVs are directly in parallel with the inputs - in other words, I was completely illiterate about the 87V's input circuitry. :)
Consider it done. I will need to set up some sort of containment so the inquisitive critters are kept safe. Maybe measure the input impedance before and after the test. Let me think about it.Assuming there is anything left of the 87V when I am done with it, I would be willing to attach it to a 1.2KVDC power supply and let it sit for a long term test. Say a week with the meter in the DC volts setting.That would be an interesting test.
If anyone ever comes across a handheld meter that uses a MOV without any additional limiting device/s, please let me know.
I am VERY interested in knowing what meter this is.
OK, Fluke 87V is not a very good product. What about Fluke 289, 28II or 179??
Yeah right !OK, Fluke 87V is not a very good product. What about Fluke 289, 28II or 179??
Does this look like a multimeter shootout thread or a "Which multimeter should I buy?" thread? :-//
The 87V is supposedly the yardstick meter, the industry standard for excellence, the meter that can do no wrong.
So far joe's only unboxed it and noted a clunky user interface (how many secret power-on modes does it have?) and cheap fit and finish (poor plastics, bent shield).
Testing's not over yet. Not by a long way.
The 87V is supposedly the yardstick meter, the industry standard for excellence, the meter that can do no wrong.Yeah right !
You're new here aren't you ?
Tucked way back on P13 of this 100 pages of goodness:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg708183/#msg708183 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg708183/#msg708183)
Funny, that poll was a fair amount of time ago as well. Yes, I have read several comments where people felt something was wrong. Indeed, it may have been. That's partly why I am doing this series in smaller chunks as well. It gives people time to digest what is going on and ask questions.
I still need to run the continuity tests and make sure I don't see any susceptible sweet spots. Then it's onto more destructive testing. My plan for the next part is to run the tests in the following order:
open fuse test
AC line
piezo grill starter
ESD gun
transient test to failure (if it can be repaired, I will go ahead and do that)
rotary switch cycle testing
long term 1.2KVDC for rsjsouza
Fungus like the drop tests so I may drop this thing on the block of wood as well
Again, all of this could change depending how the testing goes....
Piezo ignitor and Methanol upgrade required ?I'm sure Joe has a few guns too. >:D
I could shoot it with my fuse powered cork gun. :-DD
I can place it flat in the board.
Dave's running a live switch cycle on his second channel. I watched it for a few minutes. Tried to calculate the resistance with the formulas shown but looks like its 1.7K ohms the one way a little better the other. Guessing I am missing something as I think he said they could only read up to 10 ohms or so. So much computing power and they resort to sticky notes. :palm:
Dave's running a live switch cycle on his second channel. I watched it for a few minutes. Tried to calculate the resistance with the formulas shown but looks like its 1.7K ohms the one way a little better the other. Guessing I am missing something as I think he said they could only read up to 10 ohms or so. So much computing power and they resort to sticky notes. :palm:
He also cleaned off the accumulated dust/debris after every bunch of cycles. :scared:
If that's fiberglass dust then it's an abrasive, just sayin'.
Maybe it's deliberate.
Does it press against the back of the case like a spring? Does it look like there's any reason to do that?I can place it flat in the board.
Doesn't necessarily mean it's supposed to be like that.
Dave's running a live switch cycle on his second channel. I watched it for a few minutes. Tried to calculate the resistance with the formulas shown but looks like its 1.7K ohms the one way a little better the other. Guessing I am missing something as I think he said they could only read up to 10 ohms or so. So much computing power and they resort to sticky notes. :palm:
He also cleaned off the accumulated dust/debris after every bunch of cycles. :scared:
If that's fiberglass dust then it's an abrasive, just sayin'.
I don't think it's fiberglass - solder mask more likely. In normal use the meter would be picked up and put down potentially dislodging the dust anyway after every use or so - you cannot replicate normal usage easily. These sorts of test can only ever be a rough guide to wear rate, and you would need to test many to get some sort of average.
It's held in place by the screws. It does not appear to spring off the back of the case. It looks like it was designed to fit flat. There are no clearance issues I see with that would prevent it from sitting flat. I see no reason for it to be bowed other than poor quality control.
IMHO every reaction is sparked by a previous action - as I said before, due to the amount of competition on the 20k count segment I honestly believe the 87V's sales figures can't support the margins it once had.
After seeing the bent shield in my brand new Fluke 87V, a member with a slightly older 87V took theirs apart and provided me with this picture. I had hoped the meter I received was a one off mistake but it appears they are bending the shield and no one is catching it. I have not yet done anymore with the 87V and it's still sitting in parts. The shield looks like it is designed to sit flat. I can place it flat in the board. The two tabs seem to be setup correctly. Maybe they cut their QC staff to make more money? Maybe it's supposed to be bent?
Too bad these large companies have no presence in these groups. If it were Brymen, I would just ask them and based on all my previous experiences with them, would have an answer in a day. I never found a contact at Danaher/Fluke.
You know, it does look bad in that picture they sent me. There's that tab on the backside that should hold it away from the board and I have not looked but I don't think the shield extends down far enough. That said, nothing says they did not change the shield design. There meter is older than mine. This same person has an older version of the meter and they said the shield was made differently in the earlier models. They said they would provide me with a picture of that one for comparison. I will post it once I have it.After seeing the bent shield in my brand new Fluke 87V, a member with a slightly older 87V took theirs apart and provided me with this picture. I had hoped the meter I received was a one off mistake but it appears they are bending the shield and no one is catching it. I have not yet done anymore with the 87V and it's still sitting in parts. The shield looks like it is designed to sit flat. I can place it flat in the board. The two tabs seem to be setup correctly. Maybe they cut their QC staff to make more money? Maybe it's supposed to be bent?
Too bad these large companies have no presence in these groups. If it were Brymen, I would just ask them and based on all my previous experiences with them, would have an answer in a day. I never found a contact at Danaher/Fluke.
The clearances from shiield to the HV input circuit parts looks bad?
The leads on the MOVs', 1k resistor etc. there should be a insulating barrier ?
Dave's running a live switch cycle on his second channel. I watched it for a few minutes. Tried to calculate the resistance with the formulas shown but looks like its 1.7K ohms the one way a little better the other. Guessing I am missing something as I think he said they could only read up to 10 ohms or so. So much computing power and they resort to sticky notes. :palm:
He also cleaned off the accumulated dust/debris after every bunch of cycles. :scared:
He also cleaned off the accumulated dust/debris after every bunch of cycles. :scared:
No I did not.
The latest test was 50,000 cycles with no interruptions.
Previous test was all.He also cleaned off the accumulated dust/debris after every bunch of cycles. :scared:
No I did not.
What happened at the 12 minute mark?
Quote: "A bit of spit on that..."
Fair enough.
It appears their older 87V's shield is identical to the one supplied with mine. It sure looks like their tab was not pushed through the slits when the shield was installed. It's too bad Fluke reps don't hang out here. It seems like something they would want to know about, then again, it seems like it has been a problem for a long time so hard to believe the supervisor's and QC are not aware of it.
True but wouldn't take much more than the line supervisor looking at one and showing the worker how to properly install them. If their supervisor can't handle something that basic, I would say they have the wrong person in that position. But it may be cheep labor. Or maybe unsupervised. Surly the workers must think, that part should fit flat and maybe I should try and slid that tab into that slit.... Crazy...It appears their older 87V's shield is identical to the one supplied with mine. It sure looks like their tab was not pushed through the slits when the shield was installed. It's too bad Fluke reps don't hang out here. It seems like something they would want to know about, then again, it seems like it has been a problem for a long time so hard to believe the supervisor's and QC are not aware of it.
You don't need to test a product for quality if lack of quality does not affect your sales. It's not cost-effective.
You don't need to test a product for quality if lack of quality does not affect your sales. It's not cost-effective.
If it follows other meters from Fluke, it is probably a MSP430 with clipped JTAG and a custom P/N. I don't recall ever seeing a larger MSP430 ROM masked. If that is correct, the cost for the customization itself is no different than a commercial part, only the volume counts.You don't need to test a product for quality if lack of quality does not affect your sales. It's not cost-effective.
Yep. If large corporations are buying these by the truckload without ever looking inside then what's the point? Got a problem? send it back.
Fluke can probably absorb 50% returns under warranty and still make a profit on these things.
(Maybe more: What's the BOM? About $50 I imagine... what's the next most expensive thing after the fuses and the precision resistors? The leads?)
What was the cost to have the custom IC made? Burden? Certifications?
Starting to work onIf it follows other meters from Fluke, it is probably a MSP430 with clipped JTAG and a custom P/N. I don't recall ever seeing a larger MSP430 ROM masked. If that is correct, the cost for the customization itself is no different than a commercial part, only the volume counts.
I doubt that the front end is something you program with JTAG? I expect it to be a full custom, mixed mode IC developed exclusively for Fluke, possibly by Fluke. I doubt it's just a remarked device but I don't know. We could ask a Fluke rep but they don't seem to hang around the forums.
Starting to work on Part 4.
I doubt that the front end is something you program with JTAG? I expect it to be a full custom, mixed mode IC developed exclusively for Fluke, possibly by Fluke. I doubt it's just a remarked device but I don't know.
It may surprise us and survive everything. What a twist that would be as it sounds like the majority feel it is just doing to fail the same. I don't think one person has told me they thought it was going to do well since I started. What's that tell you. Surly I have not shaken the confidence of the countless Fluke 87V fans.
What was the cost to have the custom IC made?The first batch of ICs would have been very expensive. A $400 price tag was probably justified.
This is the king of meters, why aren't people saying it was all a Fluke and how the 87V is going to surpass every Fluke I have looked at? Where is the confidence I keep hearing about?
Oh, were you referring to the front end? I was talking about the main processor IC, which years ago it used to be a MSP430 but I didn't keep current with the latest models (thus it could have been morphed into a custom-looking part).If it follows other meters from Fluke, it is probably a MSP430 with clipped JTAG and a custom P/N. I don't recall ever seeing a larger MSP430 ROM masked. If that is correct, the cost for the customization itself is no different than a commercial part, only the volume counts.
I doubt that the front end is something you program with JTAG? I expect it to be a full custom, mixed mode IC developed exclusively for Fluke, possibly by Fluke. I doubt it's just a remarked device but I don't know. We could ask a Fluke rep but they don't seem to hang around the forums.
Starting to work on Part 4.
Smoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....:scared: That was bait and you know it..
Just keeping you in the loop. I thought people on this forum liked getting the second by second updates.... :-DDSmoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....:scared: That was bait and you know it..
I don't know about all of that. My channel is tiny. About 10% of the followers will view it. Of those, about 10% will rate it. It's down in the noise floor somewhere, where it belongs.
Smoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....
To be clear, I wouldn't necessarily consider smoke rolling out a failure. They should have seen the smoke when the meter was certified. If the agencies are all fine with it, so am I. Of course I have done far worse to meters during this particular test and no smoke. Possible feature.Smoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....It failed the AC line test?
.... Possible feature. ....
Just keeping you in the loop. I thought people on this forum liked getting the second by second updates.... :-DDSmoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....:scared: That was bait and you know it..
https://en.wikipedia.org/wiki/Salami_tacticsIf anyone is out there who don´t know the meaning of the german expression "Salami Taktik" - that´s the perfect example to explain it... :-DDJust keeping you in the loop. I thought people on this forum liked getting the second by second updates.... :-DDSmoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....:scared: That was bait and you know it..
Salami tactics, also known as the salami-slice strategy or salami attacks,[1] is a divide and conquer process of threats and alliances used to overcome opposition. With it, an aggressor can influence and eventually dominate a landscape, typically political, piece by piece. In this fashion, the opposition is eliminated "slice by slice" until one realizes (too late) that it is gone in its entirety. In some cases it includes the creation of several factions within the opposing political party and then dismantling that party from the inside, without causing the 'sliced' sides to protest. Salami tactics are most likely to succeed when the perpetrators keep their true long-term motives hidden and maintain a posture of cooperativeness and helpfulness while engaged in the intended gradual subversion.
a gradual attack on an opposing position, group, etc.
No offense intended. :-//That is very interesting. I could not find the exact match "Salami Taktik" but the military origins is what came up.
But giving informations slice by slice, probably leading to a big surprise (at least for some fanboys), that is "Salami Taktik".
Hence the last postings in this thread are a far, far better example for the explanation of this expression as it is used in the dayly language than a wiki article (reduced to the strict military meaning).
Enough OT, I assume. Back to topic:
Time for the next slice of information???
PS.: I´m obviously not up to date. Happy to see your new video. Oh, this suspense...
With all of the love that the BM869s seems to be getting here, I figured you might want to investigate a potentially dangerous failure mode I encountered with mine about a year ago. The metal locking ring came loose from the back of the range switch shaft and was left floating around the inside of meter. I don't know exactly how much of an impact a piece of metal this size would have on the safety of the meter, but it was certainly worrying.While I normally try to steer this blog away from safety, surely any loose metal would be a concern for anyone. We have nothing to go by other than what you wrote. I can offer that I have taken mine apart a few times and that clip was a pain to get off of there. It's the first I have heard of one coming off, on any meter. Did you buy the meter new? Had you taken it apart before? I assume you reinstalled it. Did it lock into place or was it loose? Did you take pictures to document this and then contact Brymen about it and if so, what was their response? I would appreciate hearing their response and any other details you care to share about it.
You performed a completely useless test by emptying the fuse out. It's simulating a fault which would not exist. In the field you either have an intact fuse, or a blown one.
I did not enjoy having to spend $8 to replace the fuse, but I doubt the fuse wire was vaporized or had much of a gap in it. I suppose I could break open the fuse to find out...
No offense intended. :-//
But giving informations slice by slice, probably leading to a big surprise (at least for some fanboys), that is "Salami Taktik".
Hence the last postings in this thread are a far, far better example for the explanation of this expression as it is used in the dayly language than a wiki article (reduced to the strict military meaning).
Enough OT, I assume. Back to topic:
Time for the next slice of information???
PS.: I´m obviously not up to date. Happy to see your new video. Oh, this suspense...
BTW, i took 5 fluke 87V's purchased from many years ago to last month, and all of them had bent shields. I guess no one in the assembly line gave a toss about it.
Or it was being put in by automated process (machine) that is not setup right. And there is tendency not to do detailed QC in that case because machines don't make mistakes 😒
Or it was being put in by automated process (machine) that is not setup right. And there is tendency not to do detailed QC in that case because machines don't make mistakes 😒
When I say "worker" I include machines. :)
("robot" comes from the Czech word for "worker")
or
b) It's by design.
or
b) It's by design.
Maybe it's a "tamper evident" feature? Anyone who takes the meter apart is likely to reassemble it "properly" and therefore leave evidence that they disassembled it.
Did you cut up that fuse? If so, what did you find?
Did you cut up that fuse? If so, what did you find?
It was difficult to find much at all except sand. When I cut it in half in the middle and tipped the sand out the inside of the tube was too dark to make anything out. Trying to shine a light and a magnifier at the same time revealed very little. I think the fuse wire was much thinner than a human hair. Further attempts at disassembly destroyed whatever evidence remained. My guess is that the wire melted with quite a large gap in the middle.
The Fluke fan boys will be happy again.That 87V was always a bit odd with how poorly it did compared with all the other Flukes I had looked at. For the 10 people who took the time to vote for seeing it, good on you. I wouldn't have considered running it again.
Finishing up rsjsouza's MOV testing. Hope to post it along with the life cycle results this weekend. I have included a link to Motorola's paper "TVS/Zener Theory and Design Considerations" which may be of interest.Thanks for the testing, Joe. I hope the MOV test reveals yet another interesting aspect of endurance - something I have experienced in other low cost meters: MOV or thermistors either cracked or severely burnt.
There may still be a part 7. It may be worth seeing if we can determine why the previous 87V failed at such a low level compared with this latest revision. Then again, maybe it is not important. As Dave has said, they only fail on my tests, not in the field. I will leave it up to views to decide if you want to see it.
http://www.icbase.com/File/News/download/ON_Reference_3.PDF (http://www.icbase.com/File/News/download/ON_Reference_3.PDF)
Thanks for the testing, Joe. I hope the MOV test reveals yet another interesting aspect of endurance - something I have experienced in other low cost meters: MOV or thermistors either cracked or severely burnt.
Regarding the usefulness of investigating an older production 87V: if there is evidence of a design change that triggered the premature failure, that will at least help educate the used market to look for specific traits of older production runs.
The HIOKI handheld meter I previously tested uses a similar design.
Eventually, I may do that. For now, am still focusing on that 87V. I ordered up some new parts today to try some destructive testing with rather than using the Flukes.The HIOKI handheld meter I previously tested uses a similar design.Torture it on the rack!
The larger resistors were warm enough to smoke. What do you think these small ones will handle 4 Watts for a minute?
The video for the remaining tests of the Fluke 87V are now on-line. Enjoy.Thanks Joe for the HVDC tests on the MOVs - although uneventful, they show how a good design can withstand some overvoltage (it was not the case of my old deceased meter).
the old resistor is a carbon-core part that i have not seen for decades,Although the brown resistor looks old, it is a carbon molded resistor that is well into production. Tyco's CBT series (https://www.mouser.com/ds/2/418/NG_CS_1309350_PASSIVE_COMPONENT_0807-1235534.pdf) is quite similar in physical appearance.
the new one is a flameproof type with a ceramic core to disipate heat and a metal film coating.
The larger resistors were warm enough to smoke. What do you think these small ones will handle 4 Watts for a minute?It's not all about size.
Glad you found it helpful. One thing to keep in mind, obviously the switch was in the off position. The 87V does not switch in the low voltage clamp when it is off. I doubt very much that the PTC, surge rated resistor and clamp would have survived with a 1.6KV DC applied. If you crept up on it so the PTC had time to switch, I doubt it would like a over a KV across it. And, no I will not offer to run that test for you on the 87V. :-DDThe video for the remaining tests of the Fluke 87V are now on-line. Enjoy.Thanks Joe for the HVDC tests on the MOVs - although uneventful, they show how a good design can withstand some overvoltage (it was not the case of my old deceased meter).
The selector grinding really looks ugly and surprising to such an expensive Fluke. In my opinion the 87V still does not deserve any endurance prize when compared to some of its cheaper brethren.
Very interesting outcome. Makes it clear that it’s not a problem with the fundamental design. I think the previous failure was just a fluke.I no longer believe this was a design problem or a component problem. I also don't believe it was a quality problem on Fluke's part. This meter was fairly old and I wonder if something conductive had come off at some point. Even if this were the case, I don't see where it would have been able to arc and cause this sort of damage. I monitor pretty much each transient during the tests to see if something starts to breakdown. Even if the transient generator has some major fault and I missed seeing it with the scope, it's not capable of putting out more than what that last test I ran.
The fact it was an old meter with no dependable record of its history leaves open the possibility those components had already been stressed to the point of failing prior to the test being run. I suspect the result using the repaired meter (with new diodes) is more typical of what you may expect.You make a very good point and while I have had several people offer to provide me with older meters or request me to run them, I typically decline mainly for that reason. In this case, I personally know the person who bought the meter brand new and know they do not work on line voltages, normally. It was a gamble to run it and it seems in this case, it corrupted the data. Like you, I do not believe a new 87V would ever fail like this after seeing how the meter is designed and with all of the tests I ran.
The fascinating thing to me is the apparent ease with which you manage to repair a blown up meter :)
...
From a mechanical standpoint, I don't like the 87V switch wear but it was making good contact and still better than most of the meters I have looked at.
...
Today, after almost three years, we set a new milestone with this thread. The admins were called in to censor a few posts. To try and avoid future problems, I have updated the first post to include some basic rules and guidelines to follow if you plan to post on my YT channel.Wow, that is quite odd. The discussion was quite civil in my opinion. Perhaps there is no desire to criss cross feuds happening in another platform. Oh well... Back to your normal programming I guess.
I was surprised myself and did not think I posted anything that would warrant having the posts pulled. I didn't even consider it a feud of any sort. I suspect they just did not like being called out for advertising on my channel and posting misinformation. Read the rules and if you can't follow them, there is no need to tell me you are unsubscribing over them. I won't care. Just unsubscribe and move on.Today, after almost three years, we set a new milestone with this thread. The admins were called in to censor a few posts. To try and avoid future problems, I have updated the first post to include some basic rules and guidelines to follow if you plan to post on my YT channel.Wow, that is quite odd. The discussion was quite civil in my opinion. Perhaps there is no desire to criss cross feuds happening in another platform. Oh well... Back to your normal programming I guess.
...
From a mechanical standpoint, I don't like the 87V switch wear but it was making good contact and still better than most of the meters I have looked at.
...
As an 87V owner I was also surprised and concerned by the awful rough movement developing in the rotary switch, although it's difficult to make sense of what is happening (how it 'feels') based on the sound as reproduced on the video. I gave it some thought and suspect it is the result of two things: the spring contacts being slightly 'loose' in their housing (by 'loose' I mean the tension holding it in place may be lower than optimal), and secondly the fact you use a constant speed when turning the switch on your jig. I would suggest the latter, in combination with the less than secure spring retention, allowed a sympathetic chattering to develop.
Chattering will be dependant on a number of factors: the amount of friction between spring contact face with plated track, the surface area of the contact face (which will increase as small flats are worn into them as they bed in), and the base spring tension pressing the two components together (oh, and speed!). If the spring retention mechanism allows enough flexibility such that friction overcomes its ability to slide smoothly (and thus sticks for a fraction of a second) then you will get sympathetic chattering, however this will be exacerbated by using a constant speed allowing the pattern to be imprinted into the track itself. Once established there will be positive feedback and things will only get worse as the procedure continues. Note that a lubricated track may have reduced the friction to the point where sticking would not occur - but all the other factors need to be in place before this would become a critical factor.
(There are similarities with using a parting tool in the lathe, the factors that cause chattering are similar, and if nothing can be done about the stiffness of tool mounting or play in headstock bearings then adding lubrication and/or adjusting cutting speed often resolves the problem)
Such perfectly constant speed provided by your test jig is not something that is seen in real life when simply turning the switch manually, so the chances of developing such a pattern of chattering will therefore be reduced. I do understand your idea about reducing the possibility of heat being generated due to turning the switch too rapidly but I also think you should vary the speed too.
It may be too late for that test example now (given the state of the tracks), but perhaps re-tensioning the spring contacts so they are held in place more firmly, a few seconds on a buffing wheel to round off any sharp flats formed on the spring contact faces, and perhaps a little lubrication would restore proper function.
It might be worth investigating where the dial noise comes from.
eg. Put some very viscous grease in the white switch dial thing to dampen any movement of the contact springs where they touch it.
This would let you know if the noise comes from PCB scraping or rattling of the springs in the housing.
chrimony
4 hours ago
@6:10 Surprised to see the plasma outside the bulb.?
Getting ready to look at another meter. I've been busy repairing an old scope that a friend of mine gave me that happens to be just like one I had given away a few years ago. I have finished it up but have some cleanup to do along with some other spring time work that needs to get done but I hope to get started this weekend.That's the same one my sparky mate uses for pretty much everything domestic and industrial.
Again, I want to than those of you who have offered to pitch in and buy me this meter to run, or out right offered to pay for it. I appreciate the gesture. Maybe one day I will open some sort of account to allow people to donate. For now, consider the small bit of data I supply as my way of giving back to the technical community.
Yes, the meter is here.. It looks scared..
There may be a part 2 to talk about the sensor's design. Enjoy.
With the low freq. reference and working in the few megs of coupling, it may explain why the unit has troubles with high frequency signals. I wonder if they would be better off making the final measurement with the reference disabled. Talking out of my ass. I really have no idea how it even works yet....As this is predominantly an electricians DMM I wonder how the non-contact feature work with motor speed control inverters ?
As this is predominantly an electricians DMM I wonder how the non-contact feature work with motor speed control inverters ?I don't have any motors like this. I could try it on the mains panel but the loads in the house are going to be fairly clean.
How does it sense approximate voltages and currents by comparison to a scope and current probe ?
Thanks Joe, exactly what I was wondering about.
***
Just to add, I forgot to mention that the Omron controller uses PWM and was surprised the T6 could read it. I am not sure why it had so much trouble with some of the other waveforms I was testing with. Attached is looking at one phase from this controller.
To me, it makes no sense that the T6 could handle the PWM from the Omron VFD and have problems with some of the waveforms I used with the ARB. A few people had pointed out how when I started to move the wire with my finger that the T6 started to read the voltage. Maybe there is something else going on there.Surely it's just sensitivity related....real power levels vs little signal level stuff.
Some reviewers have said "this thing sucks, it doesn't work at all". You found that it sometimes works, but sometimes not.
I'd guess there is some factor "X" at play regarding the conditions in which it is used, maybe alignment of the wire under test or something?
A puzzle for sure. On the other hand, if a test instrument is not reliable, then how can it be trusted?
Hard for me to say what the use cases would be for this meter. I wouldn't say a EE would never have a use for the T6 but it is not a tool I would ever use on a bench. I personally could see non-electricians using the T6 in certain cases.
Hard for me to say what the use cases would be for this meter. I wouldn't say a EE would never have a use for the T6 but it is not a tool I would ever use on a bench. I personally could see non-electricians using the T6 in certain cases.Everybody's freaking out about how if you'll die if you touch the metal stuff but it's obvious Fluke would have thought of that on day zero.
The main problem I see with it is that you need a lot of space around a wire to be able to take a reading. That really limits where you can actually use it IMHO.
The other problem with the non-contact voltage measurement of the T6, is that it is referencing to earth. When ever I am fault finding in a panel, I am testing phase to phase or phase to neutral as that is the working circuit. Testing phase to earth is poor measuring technique, and is predominantly done when testing of absence of voltage, which the T6 is unsuitable for.
That was very effective, Joe. I hadn't thought about the case of the switch being rotated while overloaded. Dragging an arc is certainly plausible and pretty spectacular.
Interesting. At 1000 V every mA is 1 W of power dissipation. It doesn't take many watts concentrated in a small area to cause heat damage. To make a multimeter completely idiot-proof and still work effectively at reasonable cost must be quite a challenge. One possibility might be some kind of mechanical interlock where you have to operate a separate off/disconnect switch before you can turn the dial. But then even the disconnect contacts would be subject to arcing...
The new ones are only rated to 250VDC.
We have no way of knowing what happened with Kean's meter but I would not rule out high current / high voltage. If I personally had damaged the 121GW like this, I would own it. I may even try to replicate it for a video and then try to improve the design.Yeah, I'm happy to "own it". :-DD
CAT ratings while working in the home...
Joe do you have any surge protectors plugged into these circuits at the time of the strike? Even if working some of them could be toast inside, if so photos please. Folks capable of making informed engineer level reports about strikes are not common so your opinion and photos would be a plus.
Well, it's starting to look bad. I had my old HP spectrum analyzer apart for service and went to set it back up only to discover that I have some major problems with the test equipment. Most of this is very old and for insurance, it's a bit of a question what to even do about it. As it stands, I can't even access the level of damage because the equipment I need to use is dead.
Well, it's starting to look bad. I had my old HP spectrum analyzer apart for service and went to set it back up only to discover that I have some major problems with the test equipment. Most of this is very old and for insurance, it's a bit of a question what to even do about it. As it stands, I can't even access the level of damage because the equipment I need to use is dead.
Well, shit, that's bad :(
..Also on the plus side, my trusty PACE soldering iron survived.Maybe Aaron could send out a new one (I mean, just in case..), you've been though a lot! Hope the camera wasn't charging..
It's not that bad. The house was not damaged and no one was injured.
..Also on the plus side, my trusty PACE soldering iron survived.Maybe Aaron could send out a new one (I mean, just in case..), you've been though a lot! Hope the camera wasn't charging..
It's not that bad. The house was not damaged and no one was injured.
Yeah, thank goodness. :phew: Keeping my fingers crossed for your T&M gear that there aren't any more casualties.
My old HP VNA appears to have survived for the most part.
Went to check the Signal Hound and other USB devices, knowing full well what a poorly designed that bus is. Sure enough, everything was dead. After checking the PC port (I had to add a board in the PC to get that Signal Hound stable), the cables, then the hub, it turns out the hub was dead. I have two of these Anker hubs. Made a swap and everything fired up. :phew:
Here the insurance companies pay up to a predefined amount of money for electronic equipment according to your contract.
Hello Joe. I'm sorry to hear that. When these things happen you start thinking like a prepper. I'm sure that once you have repaired or replaced your equipment you will be thinking about how to avoid lightning strikes again.
Luckily we only lost a TV set many years ago. Here the insurance companies pay up to a predefined amount of money for electronic equipment according to your contract.
Harbor Freight DMM? :-DD
That or an AM/FM radio. I could see something with an antenna being "fried" by EMP.
So, more dead electronics. I have a device that has several transistors, microcontroller, switches and such. This device was not plugged in at the time of the strike. I went to use it and it was totally dead. I opened it up. They use a glass fuse. The glass was shattered. Transistors were split in two. Several traces were gone. Again, it was not plugged in.
Cable box?
The fuse is in-line with the secondary of a power transformer. The primary would normally go to the AC outlet. It was not plugged in and that glass shattered like what I have shown many times with my testing.So, more dead electronics. I have a device that has several transistors, microcontroller, switches and such. This device was not plugged in at the time of the strike. I went to use it and it was totally dead. I opened it up. They use a glass fuse. The glass was shattered. Transistors were split in two. Several traces were gone. Again, it was not plugged in.
Holy smokes! :o How in the world did it shatter the fuse? Was it that close to the tree?
Wow... the sprinkler system then took quite a hit. I can imagine, as the "step voltage" is quite high.Harbor Freight DMM? :-DD
That or an AM/FM radio. I could see something with an antenna being "fried" by EMP.
HF meter is a very good guess. I'll give you another clue, the transient did not come through the power cord, or through the air. You know it hit a tree....
So, several traces, three transistors, exploded glass fuse and a shorted 104 cap. After about 2 hours of work, I tried to run it and the microcontroller is hot. No other activity. On the plus side, easy to order a new one and get on with the next video... I've got a date with a cheap meter and want to design the most unimpressive differential probe ever...
Internet modem(our old one had a fuse)
Wow... the sprinkler system then took quite a hit. I can imagine, as the "step voltage" is quite high.Harbor Freight DMM? :-DD
That or an AM/FM radio. I could see something with an antenna being "fried" by EMP.
HF meter is a very good guess. I'll give you another clue, the transient did not come through the power cord, or through the air. You know it hit a tree....
So, several traces, three transistors, exploded glass fuse and a shorted 104 cap. After about 2 hours of work, I tried to run it and the microcontroller is hot. No other activity. On the plus side, easy to order a new one and get on with the next video... I've got a date with a cheap meter and want to design the most unimpressive differential probe ever...
("step voltage" is a technical term we used in Brazil to name the difference of potential between a "living thing's" feet while walking in the ground close to an electrical event such as a lightning strike - this was particularly troublesome for cattle farmers).
The fuse is in-line with the secondary of a power transformer. The primary would normally go to the AC outlet. It was not plugged in and that glass shattered like what I have shown many times with my testing.So, more dead electronics. I have a device that has several transistors, microcontroller, switches and such. This device was not plugged in at the time of the strike. I went to use it and it was totally dead. I opened it up. They use a glass fuse. The glass was shattered. Transistors were split in two. Several traces were gone. Again, it was not plugged in.
Holy smokes! :o How in the world did it shatter the fuse? Was it that close to the tree?
Wow... the sprinkler system then took quite a hit. I can imagine, as the "step voltage" is quite high.
("step voltage" is a technical term we used in Brazil to name the difference of potential between a "living thing's" feet while walking in the ground close to an electrical event such as a lightning strike - this was particularly troublesome for cattle farmers).
BINGO!!! We have a winner!!! :-DD
The solenoids are very close to that tree. I checked their resistance and cycled them. Everything appears fine.
I've seen bigger transients captured on Youtube.
:-DDI've seen bigger transients captured on Youtube.
Sure, but they weren’t aimed at your home .... we just need a nickname for you now.
Lightning Joe?
Anyone????
Joe, I don't know what control unit you had or how many stations, but I recently replaced an ancient Toro unit (https://www.pluginreplacements.com/products/toro-model-ecx-8-zone-sprinkler-irrigation-timer-panel) with this one from Orbit (https://www.orbitonline.com/products/sprinkler-systems/timers/timers/easy-set-logic-all-weather-sprinkler-timer/9-station-outdoor-swing-panel-timer-2619). The advantage is that it is enclosed, which even in a garage it will probably have a long life (my older unit was eaten from rust coming from dust and spider webs).
:-DDI've seen bigger transients captured on Youtube.
Sure, but they weren’t aimed at your home .... we just need a nickname for you now.
Lightning Joe?
Anyone????
Nearly.......Joe Lightning ! ! !
That was a concern of mine as well; both units (the old and the new) only use it for the RTC and to keep the programming in a power failure. I explicitly avoided the Wi-fi connected units because of that.Joe, I don't know what control unit you had or how many stations, but I recently replaced an ancient Toro unit (https://www.pluginreplacements.com/products/toro-model-ecx-8-zone-sprinkler-irrigation-timer-panel) with this one from Orbit (https://www.orbitonline.com/products/sprinkler-systems/timers/timers/easy-set-logic-all-weather-sprinkler-timer/9-station-outdoor-swing-panel-timer-2619). The advantage is that it is enclosed, which even in a garage it will probably have a long life (my older unit was eaten from rust coming from dust and spider webs).
Your ancient Toro controller was much newer than mine. :-DD Mine uses a mechanical timer with programming pins. Why they even put a microcontroller in there, I am not sure.
I started to look at new ones but they all take a battery for the RTC. I don't need it to call my cell phone that I don't have have, update my blog or graph my water usage. It's grass, it gets water, don't over complicate it. :-DD
I plan to start work on the Meterk MK01A soon.Kind of amazed it stayed in focus (if it only knew what was in store for it, it would be doing the 4th of July quiver).. :-DD
I plan to start work on the Meterk MK01A soon.
Now I need some sort of Joe Lightning intro for all my videos along with an action figure. :-DDFits you quite well IMO Joe, when at home busting meters, sparks and smoke all over the place and when you're on the drag bike .....lightning fast !
Hi there, im looking forward to see how the mertek meter performs. In addition to comments on the video, could you show the ceramic fuses internals?I plan to pull both fuses apart after seeing where they open up at.
Nice job with that new "spare parts" diff probe, Joe.
That was one fine "8 Mhz probe" :-+
Hi thereHmm.. 161 listings with much better than avg prices, but only 32 feedback's? My nose is telling me :bullshit:
Is this the same MICSIG DP10013 model ?
https://www.ebay.com/itm/Micsig-Oscilloscope-1300V100MHz-High-Voltage-Differential-Probe-Kit-High-Quality-/123239228604?roken=cUgayN&soutkn=EvpMYC (https://www.ebay.com/itm/Micsig-Oscilloscope-1300V100MHz-High-Voltage-Differential-Probe-Kit-High-Quality-/123239228604?roken=cUgayN&soutkn=EvpMYC)
But off course you get the risk of getting stuck..
Hi there
Is this the same MICSIG DP10013 model ?
https://www.ebay.com/itm/Micsig-Oscilloscope-1300V100MHz-High-Voltage-Differential-Probe-Kit-High-Quality-/123239228604?roken=cUgayN&soutkn=EvpMYC (https://www.ebay.com/itm/Micsig-Oscilloscope-1300V100MHz-High-Voltage-Differential-Probe-Kit-High-Quality-/123239228604?roken=cUgayN&soutkn=EvpMYC)
But off course you get the risk of getting stuck..
For me it said shipping was free.. (a tempting way to toss $50 but I still smell :bullshit:)
Joe, how did that hot date go? (with the meter..) Is she smoking yet? :scared:
If I understood his last comment, he has a store and plans to sell the meter. Similar to the other review where the retired guy gets his free bling for giving thumbs up. In my case, I could care less. I'm getting nothing out of it.
Hi there.
Does this device is prone to RF interference ? Can you pass the RF antenna to check that its readings are changed ?
Speaking of RF, putting it on the input jacks would be good too. The U127xA had an issue with that.
Nicely done as usual Joe! :-+ We can forget this one as a newbie best buy.. I'll post a link to his channel and see what he says.
*edit - He may not want to promote it in his "store" anymore. I was thinking about 3 of these as disposables but shipping to Canada doubles the cost, so yeah - I think not. Thanks for a really big sheww..!
Nicely done as usual Joe! :-+ We can forget this one as a newbie best buy.. I'll post a link to his channel and see what he says.
*edit - He may not want to promote it in his "store" anymore. I was thinking about 3 of these as disposables but shipping to Canada doubles the cost, so yeah - I think not. Thanks for a really big sheww..!
I read your post. Here is a partial list if what I see as the MK01A's shortcomings:
- Battery can be installed incorrectly. Even the UT61E has different dimensions in the battery holder for the pos/neg. If the user is not paying attention, he doesn't deserve a METERK!
- There are no captive tabs on the large fuse holder to keep it in place if the meter is dropped. The case also has nothing in the molding to secure it. Again, if you can't take care of your things, you don't deserve a METERK!
- When ramping the 10A current input, the supplied leads failed before the 10A fuse blew. Ultimate input protection against arc flash!
- I'm not even sure what to say about the glowing small fuse. Well, it was a cheap unfilled ceramic body. The type Fungus does not believe exist. :-DD You are never satisfied, are you? Hey, at least is ceramic and not glass cheapies.
- Capacitance will not zero out without adding an external capacitor. Well, in order to use the capacitance meter you would need one capacitor anyways... What is the problem in adding one more?
- Very slow auto ranging for a moderate sized capacitor. The same for lower value resistors. Youngsters are so impatient these days... :palm:
- When in AC mode, selecting frequency will require a zero cross for the meter to read it. A METERK! is designed for the audiophile crowd that tolerates only absolute purity on their sinewaves.
- When in AC mode, cases like a a full wave rectified signal that is unfiltered can not be read. Exactly. How dare you submit a METERK! to such impure waveform?!? Blasphemy!
- When in AC mode, is the input is and AC waveform with a DC bias, the meter may not display the correct value. In my setup I show the meter reading between 4 volts and 42 volts. Read the two above.
- When in DC mode, if the the input is an AC waveform with a DC bias, the meter will not display the correct value. I don't know why you insist in feed the METERK! with such impurities... I think you are trying to corrupt its soul.
- In frequency mode, the meter appears to be susceptible to 3KHz and will display low battery. This is to inform the user he is finally crossing the upper bandwidth of that impure audio system called POTS and entering a new dimension in audiophile domain.
- With a 180MHz 20dBm signal (roughly 3V), the meter will display more than 50 volts. That frequency is too much even for the purest audiophile domain.
- Why do they put the vias in the rotary switch pads? You are not as famous as Dave yet. :)
- The mA lead was not soldered. There were no signs that the solder had wicked to the terminal. That shouldn't block the user from moving forward. Basic soldering skills for the hobbyist are critical for a solid career.
- The stupid little piezo grill starter killed it. The only meters that are damaged by that are UNI-Ts and the lowest of the low. If the gun had killed it, I may have been alright with it but no, its the test that hardly does anything. Shame on you for subjecting a METERK! to these abominations!
Also, I have updated the spreadsheet to include this meter.
Since a "real review" now exists, maybe I should remove those comments? As y'all know, I preview a lot of channels for sharing and I've seen of lot of "staged pro's" (in Spanish and English) and this guy's OK. Any care to opine with a yea or nay?
Shame on both of you for taking the time to destroy a man's way of living with blatantly useless reviews... :-DD
I have some carefully crafted design decisions for you:
I review another Keysight guys channel's speaking in Portañol too.. :-DD (at least that's how it sounds to me..)
Now who knows about transients like Lightning Joe?I review another Keysight guys channel's speaking in Portañol too.. :-DD (at least that's how it sounds to me..)
The only thing that caught my eye with your posts was their first response where they write "I said "for low voltage home hobby"", yet they demonstrated the meter attached to the mains without a care in the world. I guess they have never seen a large transient on their lines. Oh, that's right, the upstream fuses, transformer and lines limit the energy. That is until your tree gets hit and bypasses the whole mess. :-DD
Nor me Joe, I review another Keysight guys channel's speaking in Portañol too.. :-DD (at least that's how it sounds to me..)Who is that, Cliff? I would love to take a look at the video.
Nicely done as usual Joe! :-+ We can forget this one as a newbie best buy.. I'll post a link to his channel and see what he says.
*edit - He may not want to promote it in his "store" anymore. I was thinking about 3 of these as disposables but shipping to Canada doubles the cost, so yeah - I think not. Thanks for a really big sheww..!
I read your post. Here is a partial list if what I see as the MK01A's shortcomings:
- Battery can be installed incorrectly. Even the UT61E has different dimensions in the battery holder for the pos/neg.
- There are no captive tabs on the large fuse holder to keep it in place if the meter is dropped. The case also has nothing in the molding to secure it.
- When ramping the 10A current input, the supplied leads failed before the 10A fuse blew.
- I'm not even sure what to say about the glowing small fuse. Well, it was a cheap unfilled ceramic body. The type Fungus does not believe exist. :-DD
- Capacitance will not zero out without adding an external capacitor.
- Very slow auto ranging for a moderate sized capacitor. The same for lower value resistors.
- When in AC mode, selecting frequency will require a zero cross for the meter to read it.
- When in AC mode, cases like a a full wave rectified signal that is unfiltered can not be read.
- When in AC mode, is the input is and AC waveform with a DC bias, the meter may not display the correct value. In my setup I show the meter reading between 4 volts and 42 volts.
- When in DC mode, if the the input is an AC waveform with a DC bias, the meter will not display the correct value.
- In frequency mode, the meter appears to be susceptible to 3KHz and will display low battery.
- With a 180MHz 20dBm signal (roughly 3V), the meter will display more than 50 volts.
- Why do they put the vias in the rotary switch pads?
- The mA lead was not soldered. There were no signs that the solder had wicked to the terminal.
- The stupid little piezo grill starter killed it. The only meters that are damaged by that are UNI-Ts and the lowest of the low. If the gun had killed it, I may have been alright with it but no, its the test that hardly does anything.
Also, I have updated the spreadsheet to include this meter.
...
- I'm not even sure what to say about the glowing small fuse. Well, it was a cheap unfilled ceramic body. The type Fungus does not believe exist. :-DD
Thanks, Joe. You've developed quite the suite of functionality tests. Great job catching several issues that, until your video, I hadn't seen anyone else mention about this DMM.
:-DD :-DD I couldn't let you sit on the sidelines....I believe! \$\Omega\$
- I'm not even sure what to say about the glowing small fuse. Well, it was a cheap unfilled ceramic body. The type Fungus does not believe exist. :-DD
I havn't seen a post like this in a while.
The Mertek ended quite soon as many uni-t's, by the ESD. The video was very elaborated and to be honest maybe the expectations were worse, like failing at the rectified 230V on the temperature / mV range.
If are starting and wanna test some circuits to 230V or 110V use back to back transformers to isolate, reduce the amount of energy from the mains. This transformers can be found from older power bricks |O cell phone , game consoles, cordless phones power which didn't use switched power supplies.
I havn't seen a post like this in a while.
Hi there.
That gives the clarity of the pulse from the various devices and some sort of levels. I remember this from the uni-t ut-181A , this video that you shared looks like a follow-up . I might be wrong... Is that what you're ESD gun is replicating towards the IEC regarding EMC, but with lower energy?
I'm sure you are correct.I havn't seen a post like this in a while.I wouldn't be surprised that there are actually many more who think that way. They just don't bother to post.
A few people had asked about running a 189. It's already dead and fairly cheap.It will likley go for more than $50 USD, but then I haven't participated in almost 4 years now in Fluke ebay auctions.
A few people had asked about running a 189. Something like this may not be too bad.
You know you increased the perceived value of this meter, right? :-DD:-DD I swear it's not my auction and I have no idea who is selling it. :-DD If it had a buy it now option for $50, I would take it and do what I plan to with it. Then sign it with a grim reaper 14 KV or Bust logo and relist it as genuine Joe Smith artwork for $1 (parts only). :-DD Maybe I could break even. :-DD
why not blow one to hell, then re-list it on EvilBay? >:D
If it has the grim reaper drawn in joeqsmith style...why not blow one to hell, then re-list it on EvilBay? >:D
Will it increase the value? :-DD
To be honest, I don't believe so. I see a lot of car analogies posted that go something like:
"Wait, you just put 2000 volts across a meter that is clearly marked 600volts. That would be like driving your car into a brick wall at 100 MPH and expecting it to be fine. Your stupid." :-DD :-DD
To be honest, I don't believe so. I see a lot of car analogies posted that go something like:I suspect they don't use this analogy for your rotary switch tests...
"Wait, you just put 2000 volts across a meter that is clearly marked 600volts. That would be like driving your car into a brick wall at 100 MPH and expecting it to be fine.
Your stupid." :-DD :-DDI love when people butcher the language when trying to call someone stupid...
:o :o :o
https://articulo.mercadolibre.com.ve/MLV-489152168-multimetro-tester-fluke-189-para-repuesto-_JM
Grill starter? I think it was the grill related to the microhave transformer, a CRT tube or stun gun. Very low energy sources indeed... and precautions.MOT will not net them 20KV. He said it happened at work. I would think fairly low energy as well. Maybe he will respond.
I haven't received too many comments on the switch life cycle testing. The majority have to do with it not representing a real human. Which is very true and I am always reminded of the time I loaned out my CEM meter and the person actually turned the switch past the dead stop. One of this forums member's recently provided me with some pictures of a couple of Keysight meters from where they work. They have a rubber coating on the knob and it has started to come off. They look really bad.
I'm not sure I could come up with a good analogy for the transient tests. I would rather people not try and relate it to something that it's not.
A meter is a final product, a cars engine is a sub component. Of course the meter's front end is made up of subcomponents which really is the area I am interested in. A driver could easily hold the accelerator to the floor with the car out of gear and see what happens. There's no outside test equipment needed. Just the driver. The operator of a meter can't just turn the knob to transient mode and see if their meter self destructs. Instead they need to do things like attempt to directly measure the output voltage of their gas grill ignitor.
I don't know how the switch could be left in that deteriorating state for so long. I'd have removed the rest of the rubberized coating long before it got to looking like that 1251A. ;)
Qasim, as I mentioned, I thought about making a full review when I received the first one. There are several videos on YT showing the 189 and with it being replaced by the 189 II and then the 289, I didn't see much of a point to spending any time on it.
I have two of these so if I make a video showing a junk 189 and there is something specific that you wanted to see beyond what I show, I could possibly setup one of these meters for you as long as the test was not destructive. The one my friend gave me was used in more a mechanical environment and the case is a bit rough but the insides are like new. I doubt it ever measured line voltages. The second one is a little newer and is in very good condition.
These seem to be some of the popular videos on the 189.
When I'm critical of the 121GW everyone is telling me I am expecting too much, or I am not using it under the right conditions. So what is a reviewer to do? :-\
They do cycle test indeed on that brymen's.
No one wants even a 8 year old uni-t for free ( 50b). But Fluke 189 looks more modern than it's age and now it is clear where some brands got inspiration maybe. Now everyone is scavaging for old but good models maybe because of historical or reliability.
I've seen the video where you test pocket meters and the uni-t stood better :P What about a lifecycle on that little switch? I've seen a new pocket meter aneng 302 which has EF, true rms on Voltlog channel .. and of course basic input protection...
They do cycle test indeed on that brymen's.Despite your meter is probably a fine meter that does its job well, being manual range takes it back 20 years more (at least) - I have a UT54 that is in the same obsolete boat.
No one wants even a 8 year old uni-t for free ( 50b). But Fluke 189 looks more modern than it's age and now it is clear where some brands got inspiration maybe. Now everyone is scavaging for old but good models maybe because of historical or reliability.
What about doing a robustness test on a fluke tester or voltage detector?
fluke 1651b test meter https://ebay.us/pPhBFu
Keep in mind that i'm not favouring uni-t by any means or have some preference of this brand. and back then it was affordable. I have a pocket meter uni-t 120c and i do believe in it's specs , its price and a hard case.I didn't mean to imply that you were a fanboy; sorry. I just wanted to share the same story of a meter still perfectly usable but totally deprived of value... :)
My manual range 50b had a lot of luck . It is a obsolete model and has been now replaced with a Brymen BM235 , but it is still usable, accurate at least it's digits are better readable than aneng's.
No doubt about the fluke's since they seem to never get too old.They really age very well; since they are very durable, the main caveat is that there are many terribly battered Flukes on eBay.
The breakdown voltage and the high speed pulse may pass through less designed protection and hit the IC even it's low energy, is enought to damage it.
Have you run any of those low end differential probes everyone is raving about through your test. The results might be interesting.For the most part, I've only ran the meters that are on the list. Maybe a few fuses and lightbulbs. If you don't see a video of it, chances are I have not ran it.
KREOSAN use a taser to impose a high voltage transient on 220VAC mains, and an arc starts "somewhere". Once an arc is established, mains high current flows until I think it extinguishs at next zero-cross, if there is no inductance/capacitance/carbon to sustain it.I am not sure what you are asking. When I run these tests, I am not superimposing the transients on the AC mains, so there is no need for the CDN. If you are referring to the stun gun as the transient generator and asking if the meter sees another source. Then sure. The mains. Even with the CDN, it will still see the mains.
Relevance to robustness testing- there's no CDN here so the transient generator's energy alone is not all a multimeter would see? I think the UNI-T UT90A would not have a nice little arc.
Consider making a mains-voltage measurement and a transient starts an arc within the multimeter - either in a controlled place (inside a GDT) or between shoddy clearances.This is not true with every meter I have looked at that used GDTs. The GDTs like the MOVs sit behind a network of PTCs and surge rates resistors. It's not like they would put a GDT or MOV right across the inputs to the meter with nothing to limit the current. Of course, there is one in every crowd. Someone here actually had a meter that was like this! But I doubt you will find a meter like this from a reputable company.
Once an arc starts, the transient dissipates quickly but behind it is more (long term) energy, from mains.
In an arc flash incident, this is what causes the heat, burns, injury.
I realized using only GDT's for multimeter protection, without series MOV's, is actually terribly dangerous.
It can survive transient (only) testing, but surely blow up when mains follows through on the arc.
They are watching and learning, look at the fuses & stuff in the newer meters - better than the 20mm glass crap in the early stuff.
I think uni-t aims for the entry level for newer to electrical / electronics in controlled enviroments, but the uni-t 181A/B it should be beyound that due to it's price range. Ask them for a test :PThe UT181 is categorized by them as "Industrial True RMS Multimeters":
I think uni-t aims for the entry level for newer to electrical / electronics in controlled enviroments, but the uni-t 181A/B it should be beyound that due to it's price range. Ask them for a test :PThe UT181 is categorized by them as "Industrial True RMS Multimeters":
http://www.uni-trend.com/productslist.aspx?IntroCateId=1024&ProductsCateID=1024&BaseInfoCateId=1024&cateid=1024&ViewCateID=1024 (http://www.uni-trend.com/productslist.aspx?IntroCateId=1024&ProductsCateID=1024&BaseInfoCateId=1024&cateid=1024&ViewCateID=1024)
it's possible that if you speak to the right person an UniTrend they may support you with free meters.
it would be worth it to them to both know what needs to be fixed, and to get good reviews to people.
they are watching and learning, look at the fuses & stuff in the newer meters - better than the 20mm glass crap in the early stuff.
I think uni-t aims for the entry level for newer to electrical / electronics in controlled enviroments, but the uni-t 181A/B it should be beyound that due to it's price range. Ask them for a test :PThe UT181 is categorized by them as "Industrial True RMS Multimeters":
The UT181 is categorized by them as "Industrial True RMS Multimeters":
I hope all of the testing I have shown has not caused you to become so cynical. :-DDThe UT181 is categorized by them as "Industrial True RMS Multimeters":
Does anybody still believe them?
Show us the UL certificates, etc.
To be honest i bought one uni-t 204A at a local store to read current from solar panels or for higher loads in AC without breaking circuits.
It has ETL and Intertek logo, a good jaw, 3999 counts, temperature and some accuracy
I hope all of the testing I have shown has not caused you to become so cynical. :-DDThe UT181 is categorized by them as "Industrial True RMS Multimeters":
Does anybody still believe them?
Show us the UL certificates, etc.
To be honest i bought one uni-t 204A at a local store to read current from solar panels or for higher loads in AC without breaking circuits.
It has ETL and Intertek logo, a good jaw, 3999 counts, temperature and some accuracy
do you know what chipset it uses?
we may be able to "improve" the specs with an eeprom hack.
why not blow one to hell, then re-list it on EvilBay? >:D
why not blow one to hell, then re-list it on EvilBay? >:D
"Fluke 189 for sale, barely used"
("accidentally" neglecting to mention that it had been "used" about 5 minutes before Joe's tests blew it to kingdom come) :-DD
Resistors roasting on an open board... ♫The season is coming up.
;D
why not blow one to hell, then re-list it on EvilBay? >:D
"Fluke 189 for sale, barely used"
("accidentally" neglecting to mention that it had been "used" about 5 minutes before Joe's tests blew it to kingdom come) :-DD
"Fluke 189 for sale, calibrated, electrically test pass"
PS.: batteries not included :P
It's very difficult engineering things for transients, as the outcome is destructive - something fails and everybody scratches their heads and guesses what went wrong. It's like an airplane crash.
A Teseq is very expensive. $30K and even more for calibration and upkeep, another $6k for the H/W and F/W upgrades. For something rarely used and seen as a small regulatory hurdle, management doesn't want to put any money into it. Consider selling your transient generator ;)
You do a run and after the explosion, there is no high speed camera footage as to where the breakdown started.
It is quite a clown car for the junior engineers, who are terrified of using the transient generator and later stunned that they have no data or equation to reconsider.
Months go by and the product is late to market, pressure is on. The product has no budget dollars or room for bigger parts and clearances. I could go on and on.
It's mostly a problem of engineers not understanding the safety standards, the high costs with consulting UL/CSA over $400/hr, and the high costs of the test equipment, all to meet a few paragraphs in a safety standard- as the boss sees it.
That's a good start with MOT since there is scavanging components in big scale and buying cheap meters is a good mix for testing it's robustness as almost one time operation.
That's a good start with MOT since there is scavanging components in big scale and buying cheap meters is a good mix for testing it's robustness as almost one time operation.
Well there is always the good old cell phone charger bricks with 6VA transformers 230V / 6V in back to back configuration or a brand new 12VA 230V / 12V for the newer to start on higher voltages :P
Battery operated? A flyswatter for example
Wow... If the fault description is accurate with what actually happened in this thread (https://www.eevblog.com/forum/repair/ut71e-dead-or-something-else!/msg1776719/?topicseen#msg1776719), I propose to add a new test to your mix: EPV (Extremely Puny Voltage) breakdown test.
Actually, you are correct; I read as being applied on the input, but it was a problem with VCC. That would certainly damage things.Wow... If the fault description is accurate with what actually happened in this thread (https://www.eevblog.com/forum/repair/ut71e-dead-or-something-else!/msg1776719/?topicseen#msg1776719), I propose to add a new test to your mix: EPV (Extremely Puny Voltage) breakdown test.
Keep in mind that's a boost converter that they are using in place of the standard batteries. The battery input on any handheld may not be protected that well. At least, that is what I understood them to be doing when it was damaged.
Hammer vs the Fluke 189. Hammer wins.What the...?!?
It was way beyond wet sanding. :-DD
A bit late, but I can say, every Meterman PM55 or Amprobe PM55A I have has failed.Amprobe PM55A is a Brymen BM27s rebadged.
A bit late, but I can say, every Meterman PM55 or Amprobe PM55A I have has failed.Amprobe PM55A is a Brymen BM27s rebadged.
So you are reporting that these ALL fail? And after you replace the CR2032 battery, it still doesn't work?
Have you tried checking that the CR 2032 battery is giving its full rated voltage? I ordered 10 CR 2032 batteries on ebay and all were giving less that 3 volts, half were completely dead.
Have you tried checking that the CR 2032 battery is giving its full rated voltage?Of course I checked this...otherwise I would not be posting. The replacement batteries have all been fine, showing correct voltage with a resistor load, the screen on the meter has sharp contrast and the low battery indicator is not lit.
Are you doing harsh work with these meters or is this some unknown weakness they have?If I was I would have mentioned it. As I said, my replacement was used twice to measure a simple 5VDC circuit. Between the first and second time - as in, before it was used the second time, it failed. The other meters are also not abused in any way, usually used for low voltage DC circuits and simple tests.
You could try go up to 3.3V for power to see if it's a battery issue. But the defunct ranges seem to point out the mux, as a guess.I'm not thinking it's ESD though it could be possible. I noticed this when my meter crapped out after it had a low battery. I ordered a replacement, and my friend said the same thing. I checked my old PM55 which worked last time, and sure enough, same thing. My replacement PM55A showed good voltage on battery, but next time I went to use it, low battery...checked ohms range, sure enough, same fault. Replaced battery with fresh, tested cell, fault still exists.
I checked and the Brymen 27s has legit 61010 UL certification, so it should not be fragile for ESD.
Unless the plastic shield inadvertently allows arcs between internal nodes on the PCB...
A bit late, but I can say, every Meterman PM55 or Amprobe PM55A I have has failed.I read through your posts. First, I am not understanding why you would have posted in this thread of all places vs starting a new one. There is even a repair section that had you used, may have brought more attention/help. Is there some reason you keep buying the same meter with the same problem? There is a word for that. Then again, I have bought more than one of the same meter just to damage them so, welcome to the the club.
What happens:
- Auto mode freaks out and doesn't work (a short shows an unstable high resistance for example)
- Short detect mode shows shorted
- EF (power stick) mode works
- I can't remember what Low-Z volts does
- Hi-Z voltage works
- Diode mode acts like a short
- High ohms varies from not working to usually sounding the "shorted" beeper; IIRC high ohms will not give a stable reading
- Haven't tested current
What causes this?
The only similar thing I could find was a dying battery.
I purchased a new unit after my PM55A had failed, only to find a PM55 I gave to a friend also failed. I tested a PM55 I had and it too had failed. The replacement? Well, it tested good (testing 5V in auto mode, and shorting probes, that's it...); after a month when I went to use it to test a low voltage DC circuit again, it showed low battery ... and sure enough it failed too.
I'd like to fix them but have no idea where to start or what could have failed.
I read through your posts. First, I am not understanding why you would have posted in this thread of all places vs starting a new one. There is even a repair section that had you used, may have brought more attention/help.Maybe I should? I don't have much time to go over repair on this right now, but plan to post when I do have time, and wanted to make mention where it may be noticed. If this thing fails so easily it may be worth testing, especially if it ends up the failure was ESD induced. Maybe someone is willing to do some tests if they have one that hasn't yet died - that's why I posted here for now. Still maybe not relevant enough, I don't know.
Is there some reason you keep buying the same meter with the same problem?Because I was not aware of the problem when I ordered my replacement.
There is a word for that.Right.
Then again, I have bought more than one of the same meter just to damage them so, welcome to the the club.I bought these to use them. Before they failed, I quite liked them.
Have you tried to contact Brymen directly about what you are seeing? If so, what was their response? What about contacting AMPROBE or the distributor you procured them from?Until this latest one, all were out of warranty - Meterman has long since been bought out and Amprobe only has short warranties. I've reached out to Amprobe with no response so I will try again. Ultimately they won't be interested in telling me what the fault is anyway, thus posting here. But not in a good enough way / its own thread I guess. And if they repair it, I don't know that it won't fail again.
A bit late, but I can say, every Meterman PM55 or Amprobe PM55A I have has failed.
What happens:
- Auto mode freaks out and doesn't work (a short shows an unstable high resistance for example)
- Short detect mode shows shorted
- EF (power stick) mode works
- I can't remember what Low-Z volts does
- Hi-Z voltage works
- Diode mode acts like a short
- High ohms varies from not working to usually sounding the "shorted" beeper; IIRC high ohms will not give a stable reading
- Haven't tested current
What causes this?
The only similar thing I could find was a dying battery.
I purchased a new unit after my PM55A had failed, only to find a PM55 I gave to a friend also failed. I tested a PM55 I had and it too had failed. The replacement? Well, it tested good (testing 5V in auto mode, and shorting probes, that's it...); after a month when I went to use it to test a low voltage DC circuit again, it showed low battery ... and sure enough it failed too.
I'd like to fix them but have no idea where to start or what could have failed.
> Is there some reason you keep buying the same meter with the same problem?
I think Joe is doing a great work we are or will apprciate. See 87V two tests - two results ...
For sceptics - see autopsy of FK87V. Joe tests are very delicate I would say.
Unfortunately not mine, no idea how this has happened. Anyway prvoked my head to some questions:That's too bad. Knowing about the fuses, suggests you may have met the owner.
- Majority of damage is caused by this fused resistor, it fired PCB, internal plastic protection and even the case. Hmm... this looks like this resistor was too slow to cut connection and made huge explosion and fire. Shuould fused resisitor really explode? Is plastic protection a correct protection from fire?
- PTC was compeltely melted and changed to cloud of smoke. Maybe it shuld be heatshrinked to react faster on overrload (heat cumuates faster when PTC is shrinked?)
- MOVs exploded, but PCB trace to MOVs surrived intact, hmmm ... why?Higher resistance, more power dissipated?
- None of fuses exploded or broke connection, hmm ...all were just fine. No they were not repalced after damage, all were nicely smoked.Why would the fuses be effected. It's obvious that what ever happened, it was on the voltage circuit of the meter, not the current.
Wow that is a toasted meter .
Did some put DC voltage , MOT on that meter? Maybe a higher spike. this looks like a result of the half cycle simulator but with even more energy.
i have seen a similar chared mess in a cheaper meter once.
some idiot thought it would be a good idea to diagnose an engine problem by metering the voltage at the spark plugs! :palm:
i laughed my ass off when he told me how he killed his meter. :-DD
constant stream of high current sparks from an oil-cooled transformer can do a lot of damage.Agree that any transformer that can put out high voltage and high current could do a lot of damage but my ignition coils don't put out a lot of current. I could try to burn a meter down with one.
how are you driving the coil?MSD racing ignition systems provide far more power than anything from 'consumer' automotive manufacturers.
modern cars use capacitive discharge to give the coil a good kick.
Agree that any transformer that can put out high voltage and high current could do a lot of damage but my ignition coils don't put out a lot of current. I could try to burn a meter down with one.
Agree that any transformer that can put out high voltage and high current could do a lot of damage but my ignition coils don't put out a lot of current. I could try to burn a meter down with one.
Clearly we need to see a meter hooked up to the ~10 kV circuit on the high side of a mains distribution transformer. Though it would have to be a disposable meter as I think it would be completely vaporized in a fireball of epic proportions...
"systems", yes.how are you driving the coil?MSD racing ignition systems provide far more power than anything from 'consumer' automotive manufacturers.
modern cars use capacitive discharge to give the coil a good kick.
Joe knows and so do I. The last MSD CD drive unit I scoped was ~400V but as it was a bit older so nowhere near the Joules they make these days. Something like Methanol of top fuel with a bucket load of boost up its arse is pretty hard to light."systems", yes.how are you driving the coil?MSD racing ignition systems provide far more power than anything from 'consumer' automotive manufacturers.
modern cars use capacitive discharge to give the coil a good kick.
not just the coil - it's all about the drive circuit.
Clearly we need to see a meter hooked up to the ~10 kV circuit on the high side of a mains distribution transformer. Though it would have to be a disposable meter as I think it would be completely vaporized in a fireball of epic proportions...
Once the compression ratio nears 200 PSI and flooded with methanol things get interesting. The only way we could confirm a dodgy ignition system was to scope its outputs into the coil packs. We had some strong clues from the logging to work with and we could see strong correlations between boost, RPM, EGT's and the TPS. My mate just wanted to biff the module as the coil packs had already been swapped out but the flat spots at high motor stress still remained. This was a 13B so there were only two channels of leading and trailing but the leading set have the most influence on engine performance so it could be managed with just a 2ch scope and was an easy find with one channel being ~100V down so insufficient puff to light the plugs at full boost.
Even with 30 PSIG of intake pressure, the gasoline will ignite fairly easily. Compare my MC-4 with a magneto. I wonder how many HP it takes...
That is the result of following the design recommendations from the datasheets only or had a extra touch?
That will nuke a DMM out of orbit for sure... That is required for superbikes? That will ignite wihout any flaws and a lot of HP.
We had some strong clues from the logging to work with and we could see strong correlations between boost, RPM, EGT's and the TPS.
:)We had some strong clues from the logging to work with and we could see strong correlations between boost, RPM, EGT's and the TPS.
Collecting data is part of the fun.. :-DD
Lloooolll here a idiot means a person who has ideas and the ideia was correcting the sentence :PNot so much for the little guy as passes are so short so that all the data is logged and downloaded after a run.
I comment about the special touch because the videos on the uni-t 61e and uni-t 181A that became more robust with your magic :P.
No wonder how the drag racing has that "violent" startup. They almost could fly off the road.
There must be some complex telemetry regarding the engine and it's different stages waiting to be processed . :-DMM
Guys here in NZ log EGT's only so not to turn their 'investment' into a grenade ! :-DDThe two main things I learned the most about from logging was tuning the clutch and keeping things lubricated. AFR maybe next.:)We had some strong clues from the logging to work with and we could see strong correlations between boost, RPM, EGT's and the TPS.
Collecting data is part of the fun.. :-DD
Only when you know how to interpret it and act on the info gained ! ;)
The stresses are phenomenal ...
...addictive if you like. :)
Lloooolll here a idiot means a person who has ideas and the ideia was correcting the sentence :PI didn't do much transient testing with this particular meter as I knew it would not hold up very well. It's really designed for low voltage automotive use but it could not even handle that environment. No doubt I could improve this meter but my goal was to just understand why it was so sensitive and would reset, then correct it.
I comment about the special touch because the videos on the uni-t 61e and uni-t 181A that became more robust with your magic :P.
Now I had two dead meters. Two dead meters that cost me about $1000.
Clearly we need to see a meter hooked up to the ~10 kV circuit on the high side of a mains distribution transformer. Though it would have to be a disposable meter as I think it would be completely vaporized in a fireball of epic proportions...
What is the point here, of course the meter burns up and so does the person near it.
People have been killed connecting a Fluke 87 to 2.3kV MCC. Look at the Eddie Adams' Arc Flash Fatality Video.
You couldn't get your fill on YT? There are so many videos of humans, monkeys, birds, snow ... getting across high voltage lines. There were some pretty good educational videos put out by on of the power companies. They had a portable transmission line that they would use for demonstrations.Clearly we need to see a meter hooked up to the ~10 kV circuit on the high side of a mains distribution transformer. Though it would have to be a disposable meter as I think it would be completely vaporized in a fireball of epic proportions...
What is the point here, of course the meter burns up and so does the person near it.
People have been killed connecting a Fluke 87 to 2.3kV MCC. Look at the Eddie Adams' Arc Flash Fatality Video.
If there is a point, it would be education. Many novices may get the impression that if you generate 30 kV from some kind of ignition transformer you get sparks across a spark gap. This may lead to the (wrong) deduction that a few tens of kilovolts produces sparks. Therefore if you hold something close to a transmission line carrying 10 kV or so then a few sparks will jump across the gap when you get close enough. I don't think I've seen a video that shows what actually happens in this case, when the source of high voltage has no current limit and near zero source impedance.
You can get sparks easly on static discharges on you're car, on a shopping cart or even with two tiny 3,45VA back to back transformers that can be found on older cordless phones or cell phones ( e.g. nokia 5110 chargers) and i found that 6VA can do a good job in taking out a triac silently by the worst way without tripping the multimeter and this is low power 230V isolated, so imagine novices using HV power sources and their meters ...Imagine having a document of how every novice has damaged a meter. :-DD I will be the first to admit, I damaged my poor analog Radio Shack meter several times doing all sorts of stupid things to it. :-DD
About the meters the Brymen, Fluke , Amprobe for example they make for electricians , so they have the experience and hard time on how to build a multimeter. Try the 121GW and the Brymen BM235 EEVdition :P
One thing it would be good is to show some transients that can appear on the 230Vac line to demonstrate what multimeters are dealing in the field .
This guy also experiments with various power line equipment. Here he shows a cheap meter connected to one.
https://www.youtube.com/watch?v=8nCjvNBs150 (https://www.youtube.com/watch?v=8nCjvNBs150)
This is good as my old rebranded mastech that blowed in my hand while reading the mains in AC voltage...
Brand new Brymen / AMPROBE arrived.
Brand new Brymen / AMPROBE arrived.
This is the one that is reported to fail without apparent cause after a certain amount of time?
Hi!
IMHO it is a sort of populism or show
No reason to destroy gear :palm:I have talked about the reasons why I run these tests. It does not mean that you personally will find any value in the data. That's not one of my goals.
See hysteric tread here https://www.eevblog.com/forum/testgear/dangerous-multimeter-mastech-m890g-m890g2-(aka-dc-electronics-dc03)/ (https://www.eevblog.com/forum/testgear/dangerous-multimeter-mastech-m890g-m890g2-(aka-dc-electronics-dc03)/)I have not had a low end meter survive nearly this long. I have a Mastech that has various problems. I'm on my third one now in the last 10 years or so.
NO PROBLEM with meter but topicstarter is angry!!! :-DD
I also use some DMM for about 18 years. Yes, it is not masterpiece - you got what you pay for. But it WORKS anyway.
I believe that in that videos where Dave selected the best pocket meter of price range didn't include the amprobe pm55 and voltlog it had an aneng, mastech and the uni-t 120c. In that case can you put the aneng like meter or fluke 101 ?
Sorry to be persistent but it looks to me a little bigger in height than the ones that have being tested.
Looks like True stopped posting.001 as well. ;D
A visual comparisson always helps more. I was suggesting putting side by side the amprobe and fluke 101.
Looks like True stopped posting.001 as well. ;D
Joe, one interesting meter that you may consider testing in the future is the nice PM300 from Sanwa (https://www.eevblog.com/product/pm300/); it is rated for CATIV 300V / CAT III 600V and is quite well built. It is protected by a GDT and a Varistor on a string of resistors.
Just a hunch but I suspect so, given that Sanwa is a very reputable japanese brand that would not lie about CAT ratings.Looks like True stopped posting.001 as well. ;D
Joe, one interesting meter that you may consider testing in the future is the nice PM300 from Sanwa (https://www.eevblog.com/product/pm300/); it is rated for CATIV 300V / CAT III 600V and is quite well built. It is protected by a GDT and a Varistor on a string of resistors.
Think the SANWA would survive to higher levels than this little Brymen? Did Dave do anything to it electrically in his reviews?
Just a hunch but I suspect so, given that Sanwa is a very reputable japanese brand that would not lie about CAT ratings.Looks like True stopped posting.001 as well. ;D
Joe, one interesting meter that you may consider testing in the future is the nice PM300 from Sanwa (https://www.eevblog.com/product/pm300/); it is rated for CATIV 300V / CAT III 600V and is quite well built. It is protected by a GDT and a Varistor on a string of resistors.
Think the SANWA would survive to higher levels than this little Brymen? Did Dave do anything to it electrically in his reviews?
Dave did not put it through its paces, though.
I found no evidence the Sanwa PM300 has 61010 certification. I thought the manual says "designed to" or some other ballyhoo.https://overseas.sanwa-meter.co.jp/items/detail.php?id=405# (https://overseas.sanwa-meter.co.jp/items/detail.php?id=405#)
Safety: IEC 1010-1(EN61010-1)
≦DC・AC 500V: Designed to protection ClassII
requirement of IEC 1010-1, Pollution degree II.
EMC: EN50081-1 (EN55022), EN50082-1 (EN61000-4-2)
EN50082-1 (EN61000-4-3), EN50082-1 (ENV50204)
Only a government-accredited agency can evaluate and certify ("approve") to those safety standards, at least in North America.I am not sure if that changed, but my memory may be failing. A NRTL was usually required for UL or CSA 61010 approvals (other standards may be similar). Regardless, not everyone that sells these products is required to have an agency certification mark - only third party certification testing is necessary and a proper documentation must be available to the regulatory agencies.
No self-declaration is permitted there.
It's a long snakey path to follow safety legislation in any country, who is the "authority having jurisdiction", who makes it law that products have approvals.Precisely. It is quite hard to follow every single country out there. That is why companies tend to defer to third parties with Notified Bodies and certain places allow Harmonized standards. It tends to ease things across borders.
The liability for a product failing a safety claim is what keeps most companies from selling gear with fake approvals. I see a few Japanese companies with no formal safety approvals, only claims to meet x standard.Yes, but it is all a CYA operation. If the company stands behind its own certification procedure, documentation and manufacturing control, the liability is entirely owned by them - otherwise, pass the baton to the third party. :)
Wow, someone still has an FTP site. :-DD Sorry but I can't get to it. It won't answer a ping and FTP will timeout. If you downloaded it and feel it could be of interest, just upload it on this site or put it on Googledocs. You could also just describe the test/s you would like to see ran.I put the link directly, as the forum software was inserting bogus http:// stuff at the beginning of the link (it was also surprised about the fact a FTP site existed :D )
Google shows the title as:
"PRODUCT SAFETY: Expanding Markets Mean ... - National Instruments"
North America. – National standards and laws (OSHA). – NRTL certifications, descriptive reports and N.A. Marks (UL/CSA). – UL/CSA standards similar to IEC
The proof is the product having a Certification Agency's sticker with logo and file number, or that in the owner's manual.That is where you are getting confused: the proof is not having a listing on a site but instead a statement or a test report that says so. You could potentially consult with them and obtain the latest test reports or statements of compliance (these do not need to be readily downloadable). The listing and agency mark is a product from one of these cert agencies and not a requirement enforced by regulatory agencies to have your product available for sale. Sure, you can make the case that having your product listed will help boost sales, especially in this market, but a company or a product that is not listed is not necessarily untested and does not necessarily fail to meet the regulation (UL/EN/CSA 61010 in this case).
UL Certifications Directory (http://database.ul.com/cgi-bin/XYV/cgifind/LISEXT/1FRAME/srchres.html)
Intertek Product Directories (http://www.intertek.com/directories/)
These directories list Brymen, Uni-Trend, Fluke, Mastech, Flir, Keithley, Klein, Keysight etc. multimeter safety certifications giving proof the product was tested and passed.
My position is the Sanwa multimeters are high quality builds but unknown as far as safety, misleading in their 61010 claims. I'd want to know there are no blatent design/assembly blunders making a clearance violation allowing unexpected arcing, for example.That is a fair assessment. Until you see the test document or declaration in front of you, you can't be sure.
And if you think the harbor freight meter is bad , then check this:
https://youtu.be/R693vS09hoo
Lucky one on the mains :P
"... a company or a product that is not listed is not necessarily untested and does not necessarily fail to meet the regulation (UL/EN/CSA 61010 in this case).
That is fine. It is your opinion. It doesn't mean it is enforceable/applicable/true for all scenarios/countries/etc."... a company or a product that is not listed is not necessarily untested and does not necessarily fail to meet the regulation (UL/EN/CSA 61010 in this case).
Unless I'm misunderstanding you, I don't agree - ma and pa can't test compliance to a safety standard in their garage, write up a report and say it's all good. Too much chance of corruption and mistakes.
OSHA list of NRTL's: (https://www.osha.gov/dts/otpca/nrtl/nrtllist.html) (...)Yes, that is correct. We have established that US/Can is different than worldwide. What OSHA says is restricted to US.
Slide 18 for the suggestion of a test... :-DD
Slides 21 ~ 23 as good references when you are analyzing or making modifications on a DMM.
Anyhow, I just thought it was nice how they presented the information. Quite clear in my opinion.
I have a question about a clamp meter Unit 204A that has intertek / ETL logo and a S.N. Number :P
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=503906 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=503906)
From here it looks good but check this on the manual (see attachment) On the temperature sensor 1K resistor in series. You plug the meter into 230V in this mode and its bye bye...
So they may ommit some functions during the certification?
Just a hunch but I suspect so, given that Sanwa is a very reputable japanese brand that would not lie about CAT ratings.Looks like True stopped posting.001 as well. ;D
Joe, one interesting meter that you may consider testing in the future is the nice PM300 from Sanwa (https://www.eevblog.com/product/pm300/); it is rated for CATIV 300V / CAT III 600V and is quite well built. It is protected by a GDT and a Varistor on a string of resistors.
Think the SANWA would survive to higher levels than this little Brymen? Did Dave do anything to it electrically in his reviews?
Dave did not put it through its paces, though.
I purchased a new unit after my PM55A had failed, only to find a PM55 I gave to a friend also failed. I tested a PM55 I had and it too had failed. The replacement? Well, it tested good (testing 5V in auto mode, and shorting probes, that's it...); after a month when I went to use it to test a low voltage DC circuit again, it showed low battery ... and sure enough it failed too.
Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.
Joe, something you might want to look into with the bigger Brymens and maybe other meters too:
Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.
Not sure what you've got to replicate RF keying or if you even want to give yourself a slight RF fry up. :-\
I know and watched all you did with the Gossen to get it immune to the near field and magnetiser sensitivity.Joe, something you might want to look into with the bigger Brymens and maybe other meters too:
Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.
Not sure what you've got to replicate RF keying or if you even want to give yourself a slight RF fry up. :-\
What's this about? I do normally sweep them to see if there are areas they are sensitive at. Post a link or details about exactly what they are doing, their test setup, modulation....
I played around with a few of my meters once I picked up that Gossen at 10V/m, swept to a GHz.
https://youtu.be/wYuzFtoHMqg?list=PLZSS2ajxhiQBTCU8Mq_i9jidT024A0dV6&t=840 (https://youtu.be/wYuzFtoHMqg?list=PLZSS2ajxhiQBTCU8Mq_i9jidT024A0dV6&t=840)
If you feel the SANWA can survive to even higher levels than the Brymen, are you thinking it's in Fluke 101/107 territory?I really don't know. I suspect both would be equivalent (I hope I don't eat my hat if you happen to test the PM300 in the future).
What do you feel is a mechanical flaw with the Brymen? There is something I really don't like about the mechanics but I doubt it's the same problem. Because often I run these meters to failure and I try to analyze why they fail, I want to be able to run the PCB open case. The way the LCD, switch and battery are mounted to the case, it would make it difficult to work on. I'm sure we will find out just how difficult.In the original shootout video from Dave, he found out that twisting the Brymen was wreaking all sorts of crap on its screen. But perhaps it was a different model (so many OEMs/rebrands)
Ah, the twist test.
Take your best guess where you feel the Brymen will fail.I forgot about this question. IIRC from your tests, the well built meters tend to have the point of failure around the clamp diodes/transistors. Obviously that may change to the rotary switch due to the sheer space constraints.
I know and watched all you did with the Gossen to get it immune to the near field and magnetiser sensitivity.Joe, something you might want to look into with the bigger Brymens and maybe other meters too:
Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.
Not sure what you've got to replicate RF keying or if you even want to give yourself a slight RF fry up. :-\
What's this about? I do normally sweep them to see if there are areas they are sensitive at. Post a link or details about exactly what they are doing, their test setup, modulation....
I played around with a few of my meters once I picked up that Gossen at 10V/m, swept to a GHz.
https://youtu.be/wYuzFtoHMqg?list=PLZSS2ajxhiQBTCU8Mq_i9jidT024A0dV6&t=840 (https://youtu.be/wYuzFtoHMqg?list=PLZSS2ajxhiQBTCU8Mq_i9jidT024A0dV6&t=840)
You can glean a little more about the circumstances here:
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1898834/#msg1898834 (https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1898834/#msg1898834)
Ah, the twist test.
It beats me how people manage to put their phones in the back pocket of their jeans and then sit on them without breaking them.
When people do that with wallets all their credit cards come out bent.
The uni-t 90A is the one have "fusible" tracks ?
It seems so.
https://youtu.be/aRuI_q_K5RY?t=411
That's a bit odd as that clamp is not normally engaged. Did you attempt to read the resistance of the 220V? :-DD
Actually, even if you did, I would have not expected it to fail like this. All the ANENGs I looked at survived with that full rectified 220VAC line supplied to the meters while in each mode. They actually held up better than many meters I have looked at.
So what exactly did you do that caused this clamp to fail?
Tautech mentioned the RF issue I encountered being analysed in here. Some additional info:
1. PA was open board prototype.
2. BM867S was used to measure current hitting the drain of a FET through a 50uH loaf I nductor. Connected via Pomona banana leads. Mode Amps DC.
3. There was supposed to be a decoupling cap or two on the top end of the inductor. This was missoldered.
4. PA was delivering 25W out at the time.
5. “Mental” was weird readings and eventually it froze and had to be turned off.
6. My BM867S has crashed twice since I got it so this may be a problem with this meter.
7. Issue went away when I fixed decoupling, added Pi network LPF and Hammond enclosure.
I also found the PA was oscillating at around 120MHz as well as 7Mhz. This was resolved with a 10 ohm resistor in series with gate.
I didn’t delve too much further into this as I was more interested in building the PA at the time.
I suspect that there were extremely large voltage spikes (think SMPS) at the top of the inductor here.
Really I think this is a faulty unit at this point based on this behaviour and the other crashes.
Please excuse the horrible typos in the previous post by me - damned iOS!
Thanks for testing this by the way. I'm not sure any further testing would be conclusive.
Out of interest I have another PA prototype in development which should kick out 50W this time. When I get to the same state of the build I will try again and see if I can isolate a cause.
Honestly though I'm not surprised if there are problems in these situations as they are mostly well outside what would be considered normal EMC situations. I certainly am not annoyed by the meter. On that front at least. It has a couple of annoying misfeatures.
The Hioki DT 4252 also has a Gas Discharge Tube and performed really well, with added plastic near fuse holder to prevent arcing if i remember correct.Yes, both that Hioki and the Gossen I have use GDTs and both did very well in my transient tests. Then we have meters like the UNI-T UT181A that have a fair amount of circuitry including MOVs that fail with that gas grill starter. The UNI-T is not a cheap meter and you would think that they would get it right but sadly they don't seem to have a good understanding on what it would take to harden a meter. Odd as there are so many examples out there showing how.
On the Amprobe It was funny to see GDT miniaturized and doing their job. Maybe they were properly tested before going to certification
Well about cheap it depends on which scale / type of the meter fits. The uni-t 181A is very similar to the fluke 287.. and the 287 costs a lot more, it is sluggish on plotting but it meets more safety then. Now the Keysight is not much cheap compared to equivalent meters , lets say fluke 115 / 117, [Edit the poor english, sorry ], the hioki ,brymen BM257s and fails so less value for the money.
The uni-t 181A heavly modified, with the software in labview over bluetooth must be something unique since it hasn't got a program for PC.
Now a different question. Did you perform a transient test after a drop on the aneng's?
From what I understood from your sequence of videos hardening the UT-61E, it seems to me that both MOVs and GDTs are too slow for the spark produced by the igniter, leaving only the fast transistors/diodes and the severe increase in the input series resistance as the only effective lines of defense.
Taking that into consideration, a choice must be made by the manufacturers given the added resistance has negative consequences for the bandwidth.
Am I missing something?
I have no explanation of what the issue is.Gremlins. Certainly Gremlins.
(...)
I will put this one down to quantum bogodynamics as my other half was in last time and isn't this time. She may have high bogon emissions.
Yes, you are missing something!!Uh... What exactly? The speed of the transient? I thought I had it covered on my post...
What does the speed, or better yet, let's say the rise time have to do with it? What was it on the 61E that was damaged and why?Yes, you are missing something!!Uh... What exactly? The speed of the transient? I thought I had it covered on my post...
Just a quick update on my problems with the BM867S. I tried the same set up again and the display was 100% stable this time. I have no explanation of what the issue is. I even set the bench out as close to what I remember I had it set up as and documented in my notebook. Power out was within 5% of original. Frequency spot on.
I will put this one down to quantum bogodynamics as my other half was in last time and isn't this time. She may have high bogon emissions.
Well about cheap it depends on which scale / type of the meter fits. The uni-t 181A is very similar to the fluke 287.. and the 287 costs a lot more, it is sluggish on plotting but it meets more safety then. Now the Keysight is not much cheap compared to equivalent meters , lets say fluke 115 / 117, [Edit the poor english, sorry ], the hioki ,brymen BM257s and fails so less value for the money.
The uni-t 181A heavly modified, with the software in labview over bluetooth must be something unique since it hasn't got a program for PC.
Now a different question. Did you perform a transient test after a drop on the aneng's?
I should have been more clear. I was not inferring anything about the features, quality or value, only the cost. For me, cheap is $50 USD and less. I've stated numerous times that I had never paid more than $50 for a handheld before starting these tests. These cheap meters were never used for anything beyond basic automotive use in the garage or if I needed something avoid risking my bench meters. I have always considered them disposable.
That said, when I started running the first $50 meters it was clear that one company stood out, even at that level.
I would not say my UT181A is heavily modified, at least not compared with that KASUNTEST ZT102 or even that analog meter I tested. Now if we were discussing that UT61E, that's heavily modified! :-DD Possibly the first handheld meter ever with an auto back light control.
If you go back and watch that video where I drop test the ANENG and the KASUNTEST, you will find both were damaged long before they were dropped. I had put them back together to try to get a feel for how they would hold up. I don't think I ever dropped a working one.
Well about cheap it depends on which scale / type of the meter fits. The uni-t 181A is very similar to the fluke 287.. and the 287 costs a lot more, it is sluggish on plotting but it meets more safety then. Now the Keysight is not much cheap compared to equivalent meters , lets say fluke 115 / 117, [Edit the poor english, sorry ], the hioki ,brymen BM257s and fails so less value for the money.
The uni-t 181A heavly modified, with the software in labview over bluetooth must be something unique since it hasn't got a program for PC.
Now a different question. Did you perform a transient test after a drop on the aneng's?
I should have been more clear. I was not inferring anything about the features, quality or value, only the cost. For me, cheap is $50 USD and less. I've stated numerous times that I had never paid more than $50 for a handheld before starting these tests. These cheap meters were never used for anything beyond basic automotive use in the garage or if I needed something avoid risking my bench meters. I have always considered them disposable.
That said, when I started running the first $50 meters it was clear that one company stood out, even at that level.
I would not say my UT181A is heavily modified, at least not compared with that KASUNTEST ZT102 or even that analog meter I tested. Now if we were discussing that UT61E, that's heavily modified! :-DD Possibly the first handheld meter ever with an auto back light control.
If you go back and watch that video where I drop test the ANENG and the KASUNTEST, you will find both were damaged long before they were dropped. I had put them back together to try to get a feel for how they would hold up. I don't think I ever dropped a working one.
Hello And thanks again for the clarification. For 50 "doll" mark it comes to the 101 or the Am510. I believe when you talked about the modifications about the ut61e you also mentioned the uni-t 181A and it sound was more difficult on one of the videos :
https://youtu.be/cMutvk_6xhY?t=2541
The piezzo grill starter may have low energy but it is a ultra fast spike and the clamps must be prepared for it, if any...
My question about the drop is that my aneng has failed during monituring 230V AC isolated, due to droping from my TV stand to the floor (0.5m height) front facing which result in random mode changing / enter CAL mode when wake up from SEL button.
Here are some photos of the pads for the rotary switch with some sort of grease, also one trace in the middle is pretty scuffed. This is one year of use...
Also the lens were scratch from the fall are available.
The spring contacs on the rotary switch are like brand new, without wear.
Thanks for refreshing the memory. That pulse is hard to capture on current measurement.
The ESD gun looks more harmfull than piezzo grill starter since it approaches the IEC test and again uni-t 61e modified passed that test. Maybe uni-t has corrected that in newer DMM's.
However the Amprobe pm55a, which i bet that would fail on that test, it ran without issues and got beyond the 6kv. By the way did you managed to produced the bug reported by True after the video?
About my meter looks like one of my brothers use it to measure the voltage of the flyswatter and it said it was doing OL all the time and switched to other off position while the thing still on and leads plugged :palm: . i. , before i ran the 230V ac test... I thought it was the fall but now i have the oportunity to offer one of my old meters, the uni-t 50b, teach more stuff. All bets are off for now.... :-DD
Yes in most cheap meters its more or less 30 Vrms on the current side. I've removed the Q3 / Q4 and the TVS., plug the batteries, no meter.
Just to be clear: I didn't request Vaseline, that was 001. I just suggested the spark gap test. :D
Simple test: Make a spark gap, put Vaseline on it, see if it stops sparking. :popcorn:
(and if it stops, how much higher do you need to go to get it to spark again?)
Just to be clear: I didn't request Vaseline, that was 001. I just suggested the spark gap test. :D
If that's a concern for you, next time perhaps think more, post less?
So
I want to protect selector from arc at lamels
Is silicone best isolator than air?
If you think there might be an arc then grease isn't the answer (and probably won't help).
Change the operating procedure, wear protective gear, get a better meter if necessary.
I was wrong, it helped. :-//
Now it is using my old uni-t 50b and read the manual before using it. They are the acessible meters.
The one that i've got is the uni-t ut139A , the worst of the 139 line. At least it has ceramic fuses for the claimed voltage, it has enough grip and simple to use. It will be out of reach for modifications.
I've not looked at the 139A. Just in general have not been very impressed with the UNI-T product line. I still like that 210E clamp (as a clamp only). I'm not aware of anyone I know who bought one having any problems with it yet. The 181A could also be a very nice meter with a few changes.
What is "High Voltage" actually?https://en.wikipedia.org/wiki/High_voltage#Definition
Is it 200V, 600V or 1200V? DC or AC? What freq?
What is "High Voltage" actually?https://en.wikipedia.org/wiki/High_voltage#Definition
Is it 200V, 600V or 1200V? DC or AC? What freq?
It's the best lube out there, but very expensive.
High voltage in DMM, would be around what manuals ( Safety Information ) of describe on the first pages to be aware of probe techniques to prevent hazards, starting at 30Vrms or 60Vdc . Tthe meter could have a LED of the HV or starts beeping a lot...
The numerical definition of "high voltage" depends on context.I tend to agree with their opening sentence. In the context of a handheld DMM normal use, I lean more towards what you wrote and the wiki section on safety.
......Krytox GPL 105...................Used in Aerospace and MILSPEC..................
High voltage in DMM, would be around what manuals ( Safety Information ) of describe on the first pages to be aware of probe techniques to prevent hazards, starting at 30Vrms or 60Vdc . Tthe meter could have a LED of the HV or starts beeping a lot...QuoteThe numerical definition of "high voltage" depends on context.I tend to agree with their opening sentence. In the context of a handheld DMM normal use, I lean more towards what you wrote and the wiki section on safety.
When I test meters, I talk about my low voltage transient generator. It's 6KV which may seem like a lot but in the context of the transients I can generate, it falls way short of the 15KV I tested the Fluke 107 at.
It's the best lube out there, but very expensive.Like I haven't heard that one before. :-DD
When I see something hold up as well on that 50,000 cycle life test than the Fluke 17B+'s dry contacts, I will surely let people know. I would rather see a properly designed switch than spend my time searching for the world's best lubrication.
If we are talking about Fluke, I am guessing that the grease is being used as a lubricant and not to increase the breakdown voltage. I assume the meters are designed not to arc by design (creepage, clearance). Again, a GUESS. I am not presenting this as a fact!It's the best lube out there, but very expensive.Like I haven't heard that one before. :-DD
When I see something hold up as well on that 50,000 cycle life test than the Fluke 17B+'s dry contacts, I will surely let people know. I would rather see a properly designed switch than spend my time searching for the world's best lubrication.
Strange, it wasn't dry (on the PCB) for the old 87:
https://www.eevblog.com/forum/beginners/lube-dmm-selector-switch/msg1248833/#msg1248833 (https://www.eevblog.com/forum/beginners/lube-dmm-selector-switch/msg1248833/#msg1248833)
Hey new meters to be put on the run :P Are some anengish types?
Did you ever tester one of the Non-Contact Voltage Pen tester? Some of them claim CAT IV .... CATII .. 1000V or none..
A certain Japanese manufacturer? ;DHey new meters to be put on the run :P Are some anengish types?
This will be a brand I have not looked at yet. There are many reviews and tear downs of it. Lots of positive feedback. Thing is, my transient generators don't seem to care about all of that.
I have one (4€) which shows that my wall mirror does have mains potential in it as does my work desk. :-DD :palm:Free energy!
Well this one doesn't do that and doesn't work well on my sockets . I have to use a UK to EU(Type G to F ??? blob:https://www.dropbox.com/1b062708-409e-4ccc-b9c3-485785168d62 ) adapter to work on the plugs :-DD It doesn't trip with DC voltages... Now its time to perform a test on a Isolated transformer , 220 VAC 6VA .
I would imagine they are common here as well in the electrical world. They would be much safer than jamming metal probes in things. John Ward had made a video titled "Proving Dead - Mains Electricity". May be worth watching. Not being an electrician, I will leave the training videos to much more qualified people.I watched this video when it was out and John got a lot of flak due to his dissing of screwdriver testers. I agree with the criticisms; the contactless testers can be quite unreliable (if not more) than the screwdrivers. I have encountered zillions of scenarios where false negatives were given by the contactless.
Thanks for the enlightment. I'm using this at the sockets, power cords from appliances and a project development..For this usage the contactless should be fine. Just beware if you are trying to probe through very thick or shielded connections - the contactless may not catch the voltage.
I have heard about false positives which for proving live shut off can be inacurate, but has the safety aspect of the non contact.Since you mentioned, all my contactless gadgets (the LVD2, the Keysight U1282A, the Surpeer AV4) flicker/beep when I move them over or towards a metal surface - a disturbance in the magnetic field probably causes an induced current on its sensor.
Well this one doesn't do that and doesn't work well on my sockets . I have to use a UK to EU(Type G to F ??? blob:https://www.dropbox.com/1b062708-409e-4ccc-b9c3-485785168d62 ) adapter to work on the plugs :-DD It doesn't trip with DC voltages... Now its time to perform a test on a Isolated transformer , 220 VAC 6VA .
joeqsmith would have a field day with this meter; starting at about 33:30 I put the non-volt ranges through a ring generator (90VAC, 20Hz, but the load probably took it down to about 40VAC) and the meter goes completely haywire.I have not seen any other reviews for this meter. Someone had pointed it out to me in a YT comment. They had a 3D drawing of the meter and I could see it was similar to other low end meters I have looked at and figured why bother.
Thank you; that is truly an honor to have you watching something from me - I learned so many nuggets from your videos. I would love to have the energy and time to create decent captions, but unfortunately this is a full time job on itself. I could do dubbing as well, but unfortunately this means almost re-doing the video. Oh, well...joeqsmith would have a field day with this meter; starting at about 33:30 I put the non-volt ranges through a ring generator (90VAC, 20Hz, but the load probably took it down to about 40VAC) and the meter goes completely haywire.I have not seen any other reviews for this meter. Someone had pointed it out to me in a YT comment. They had a 3D drawing of the meter and I could see it was similar to other low end meters I have looked at and figured why bother.
I don't know your language but I watched your video anyway. It's funny how the brain will put a story together just based on your voice and gestures. There is not much to these handheld meters which also helps in following along.
Yes, that input trace to what appears to be the ground plane looks bad. The large fuse you show appears to be the same that was in the Meterk. The end caps will just pull off on that one. You should find it is filled. On the Meterk, the smaller fuse was NOT filled. Contrary to what Fungus believes, not all ceramic fuses are filled safety fuses. You would need to pull it apart and have a look. It took a while before I figured out that you were using a telephone ring generator. Google pictures to the rescue. :-DD
In the end, I get the feeling there was not a lot of praise coming from you.
Funny, I wasn't thinking you were trying to damage the meter with the phone ring generator. You could get a piezo grill starter if you wanted to try and zap one. The problem I see is that they are not consistent from unit to unit.Well, a manner of speaking. I wasn't necessarily trying to damage the meter but instead putting to test if their claimed 550V of overvoltage protection was actually true.
Some details about the testing but not much...
https://youtu.be/9kcHAnGOhxo?t=30
A little higher energy test setups than what I use to benchmark the meters. Here they talk about the filler and it being packed. I think there is a bit more to it than what you see posted here. Just add some sand, its free sort of posts....
https://youtu.be/Uj0oHUSSW_8?t=13
Funny, I wasn't thinking you were trying to damage the meter with the phone ring generator. You could get a piezo grill starter if you wanted to try and zap one. The problem I see is that they are not consistent from unit to unit.Well, a manner of speaking. I wasn't necessarily trying to damage the meter but instead putting to test if their claimed 550V of overvoltage protection was actually true.
I think a distinction between the grill starter and the ring generator is that the latter is closer to the scenario where someone has the wrong range - it takes several seconds to realize the meter is under duress of a continuous voltage. The grill starter and all the tests you do are similar to a true transient hitting the equipment completely at random.
I've openend the broken anengish meter and had also some flux residue on the front side:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1924219/#msg1924219 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg1924219/#msg1924219)
Yes it is very good built quality and lots of features if considering the price .
Is it possible to create some sort of capacitive controlled, load to test the breakdown current of the HRC fuses ? That would require to test under the maximum voltage has well... lots of energy envolved.
Nothing anyone would ever attempt at home, we except ProtonicInduction. I think it was in the very last video he made he shows the large capacitor bank that he put together.
He said something bad (and correct) about the mess that immigration services make in the UK, then removed the video and disappeared. He's probably banged up in some dungeon somewhere.
Is Fluke 87V worth buying when compared to Hioki and Keysight??
joeqsmith
Please what was the verdict on your new Fluke 87V ? If I understand right it passed the high voltage test according to CAT rating but there was some wear on the rotary switch?
Is Fluke 87V worth buying when compared to Hioki and Keysight??
Dead camera batteries have prolonged the life of another meter.121GW with the latest mods ? :popcorn:
The choice of meters should provide a clue. Looks about the size of a popular meter.....
Those are some fairly low end meters in that video except for one. Some may say that in the real world, things like this don't matter. I have a much different opinion about such things.
Dead camera batteries have prolonged the life of another meter.This tells me it survived the spark and (perhaps) the "lower" (2kV, 4kV) voltages. Better than a throwaway.
The choice of meters should provide a clue. Looks about the size of a popular meter.....This gives a lot of room for speculation, given you are not saying anything about the actual popularity of the meter (only about its size) - it could be a 121GW, a Surpeer AV4 or even a more obscure brand such as... The one we talked about before.
Did I claim that "all" ceramic fuses are filled or only that I believed the ones in that $14 LIDL meter would be filled?
"High" is a relative term but I thought all ceramic fuses were "HRC" type.
(otherwise they'd use glass, which is cheaper)
Looking at the quality of the printing on this fuse, I doubt it's really by SIBA:
Was going to ask about including the uni-t 210e clamp meter but since it is very modified it can give different results from a non modified as mentioned
what about include on the spreadsheet the claimed battery life on manual for comparisson ?
Battery life for a DMM is a "how long is a piece of string" question ...
Battery life for a DMM is a "how long is a piece of string" question. The power draw depends not only on obvious factors like use of the backlight, but on less obvious factors like use of resistance, capacitance and continuity ranges (where power is expended for the test), compared to voltage measurements which are basically passive. I can see why manufacturers would decline to state an expected battery life. It is going to depend a lot on the usage profile which they have no control over.Except that Keysight advertises this for both their U1272A (https://www.keysight.com/en/pdx-2882338-pn-U1272A/handheld-digital-multimeter-4-digit-ip54?nid=-32044.1242727&cc=US&lc=eng) and U1282A (https://www.keysight.com/en/pdx-2883096-pn-U1282A/handheld-digital-multimeter-4-digit-ip67?cc=US&lc=eng).
300 hours of battery life and Keysight Remote Link Solution enabled (wireless data logging via Bluetooth)
Stay productive with 800 hours of battery life and datalogging via Bluetooth
I was using 1000mA/hr from Wiki (860–1,200 and split the differnce) for AAA Alkalines to get the 312 hrs. Dave was using 770mA/hr.
nice, but dangerous.
it should have had the probe extending from the case,
so you anchor the earth rod, and then probe the fence while ONLY holding the case.
from those images they expect you to hang it on the fence while holding the grounding probe!!
I was using 1000mA/hr from Wiki (860–1,200 and split the differnce) for AAA Alkalines to get the 312 hrs. Dave was using 770mA/hr.
Sorry to be pedantic, but the unit is mAh (milliampere-hour) not mA/hr.
Also I spotted mH/hr (millihenries per hour?) as the column header on your chart. I admit that made me LOL a little... >:D
Wow the flashlight must be super bright and efficientIt's actually very dim and not very efficient at all. The key was testing the stimulus's current limit. Many people want to show lighting an LED as part of their meter reviews. The custom meter can push about 500mA at more than 20 volts. More than enough to test my HV diodes and power any handheld meter I have seen to date but not enough to power my flashlight.
Model | Pack Description | mAh | NomCur | Backlight | MaxFunc | Cutoff | Nominal | Min |
Keysight U1273A | 4X AAA LR03 | 1000 | 30mA | N/A | 34mA | 4.2V | 33.33h | 29.41h |
Brymen BM857 | 1X 9V 6LR61 | 550 | 5.2mA | 42mA | 5.6mA | 5.8V | 105.8h | 98.20h |
Fluke 8060A | 1X 9V 6LR61 | 550 | 4.0mA | N/A | 4.6mA | 3.9V | 137.5h | 119.6h |
Sanwa PM300 | 1X 3V CR2032 | 235 | 1.4mA | N/A | 2.0mA | 1.7V | 167.8h | 117.5h |
Uni-T UT61E | 1X 9V 6LR61 | 550 | 3.2mA | N/A | 5.4mA | 1.6V | 171.9h | 101.9h |
Surpeer AV4 | 1X 9V 6LR61 | 550 | 2.8mA | 31mA | 5.2mA | 3.1V | 196.4h | 105.8h |
Uni-T UT136C | 1X 9V 6LR61 | 550 | 1.8mA | N/A | 2.9mA | 2.3V | 305.6h | 189.7h |
Keysight U1282A | 4X AA LR06 | 2000 | 5.3mA | 38mA | 7.1mA | 3.9V | 377.4h | 281.7h |
Mestek DM91A | 2X AAA LR03 | 100 | 1.7mA | 3.7mA | 3.2mA | 2.2V | 588.2h | 270.2h |
Fluke 27/FM | 1X 9V 6LR61 | 550 | 0.7mA | N/A | 1.7mA | 3.6V | 785.7h | 323.5h |
Uni-T UT139C | 2X AA LR06 | 2000 | 1.7mA | 10.5mA | 2.4mA | 2.1V | 1176h | 833.3h |
Mastech MAS830L | 1X 9V 6LR61 | 550 | 0.3mA | 30mA | 1.9mA | 4.4V | 1833h | 289.5h |
Very nice work. I am surprised that Keysight would make something with even lower life than the UNI-T. Then again, who puts glass filled plastic in their detent springs.Thanks. The U1273A is on par with the other meters if the backlight was constantly on, which is the premise of the OLED display. In my regular use I don't see it being a terrible user experience, however I am in the US where batteries are dirt cheap when compared to my country of origin.
Minor detail, in my test setup the voltage is read across the meter. Basically I did not want my shunt to come into play.The E36312A has 4-wire mode, but I couldn't be bothered. I may re-run and see if there is any influence.
I am not sure how to deal with the cutoff. Some meters' like the BM869s will run way down below the battery warning and audio alarm but it can also throw up some bad data.I am not either. The discharge rate is very non-linear; a battery drained to the cutoff level of an UT61E is quite unrealistic for practical purposes, given the meter beeps at power up and severely drops the voltage of such discharged battery.
Type Brand Cutoff (V)
----------- -------------- -------------
9V 9F22 Duracell Ultra 7.0
8.4V 9F22 Tronic 220mAh 5.8
8.4V 9F22 fullwat 260mAh 4.7
CurrMin: 1mA
CurrMax : 10mA
Hi sorry to ask again this, but do you tested with NIMH cells and had any different cut-off voltage? The uni-t 204A has different cut-off for the NIMH batteries and i've tried another brand.
So cutoff:Code: [Select]
Type Brand Cutoff (V)
----------- -------------- -------------
9V 9F22 Duracell Ultra 7.0
8.4V 9F22 Tronic 220mAh 5.8
8.4V 9F22 fullwat 260mAh 4.7
CurrMin: 1mA
CurrMax : 10mA
I've replaced alkalines for nihm on the BM235 and unit 139A to check cutoff voltage has well, but i believe had that on the aneng meter and the cut-off was always the same for alkaline or nimh as an example of consistency on battery cutoff for AAA or AA batteries.
Sorry for the lack of the details. After the unit shutdown due to lack of "juice" when turned on, a few minutes of use, took the battery out and measured with another meters , the uni-t ut50b and the ut120c, in volts mode. Also let the batteries settle down for 10 minutes and still measured the same voltage, same meters.
This experience is a bit old so didn't follow the same guidelines, because of the issue of draining to quickly the 9V alkaline batteries in Amps with clamp meter... and opt for NIMH batteries since buying alkaline would become expensive alternative
Oppsss i thought bad since the meter shuts down after low battery it becomes completly open to the battery. However the 7V cut off from the alkaline battery measured is similar with most of the 9V battery operated uni-t meters for example the uni-t 50b , using the same battery. It is on the NIMH and this meter that cut-off is different but again not the best procedure to measure voltage with real load.
What i'm trying to do is if this meter has an issue with alkaline batteries since it behaves weird after a long period of usage , when is awaken. It doesn't happen with NIMH. Problem is it worth time investing since it is a cheapo meter?
Hi there
Thanks for the information on the video.
Tested some and uni-t's before buying one... they would turn off by lack of juice in the battery and the its voltage would be around 7V ( ut58... ut50... ut200 series.. ut33 ) with alkaline battery duracell ultra... The usual was taking off the battery and put another one... and measure the old one . The thing was when i purchased the ut204A i was testing some current measuements with sotck battery and it depleted the battery to nothing in 3 hours... it wouldn't turn on where the uni-t 50b was for 3 weeks with the same battery .. and let it run till it drained... measured 7V.
So i decided to buy an duracell for the clamp and it didn't last long enought at least when using the clamp for measuring current, same 7V measurement. goes to ut50b lasts 3 weeks.. then decided to try some nimh batteries and they pretty last longer than the alkaline batteries, different voltage when meter shut down due to lack of juice... This clamp meter also has some "features" like it doesn't sleep always after the 15 minutes.
Sorry again for pulled down the battery as soon as the meter powered off on its own on low voltage till i couldn't turn on again. Temperature is around 16ºC to 20ºC, humidity up to 70% .
This way... meter powers down, open the case, take out the battery and measure voltage with another meter...Should i measure when it is still on the meter even if is supposelly powered off? I can re-run this with the 204A because it can be turned to always on...and draws 1mA in Vac mode.
This way... meter powers down, open the case, take out the battery and measure voltage with another meter...Should i measure when it is still on the meter even if is supposelly powered off? I can re-run this with the 204A because it can be turned to always on...and draws 1mA in Vac mode.
Broadly speaking, you need to know that NiMH fully drained cells "rebound" when you take the load off them. For example, a completely drained NiMH cell may have an open circuit voltage of ~1.2 V. You can put a small load on it and the voltage will drop down to 0.5 V or lower. Take the load off the cell and the voltage will rapidly rise up towards 1.2 V again. The best way to see this happening is to have the cell attached to the voltmeter when you do this experiment.
Thanks again and i've yet tested with another battery operated device, which gave similar result ( less voltage drop) as you mentioned:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2102320/#msg2102320 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2102320/#msg2102320)
Alkaline cells don't behave the same way. They have a very small rebound or recovery, but it is much less pronounced.
I assume you own all of them that use 9V batteries and tested them to make a statement like that. If you watched that short video, you would have seen how low my UT61E ran. rsjsouza also tested their UT61E and posted the results. I also posted data for the UT90.
Starting to work on a new video but the German's are getting me down. But if you like seeing old meters, stay tuned..Oh, no! What did Gossen do this time?!? Did they set radiowave or magnetic weapons around your house to make all meters go wild?
Starting to work on a new video but the German's are getting me down. But if you like seeing old meters, stay tuned..
a real one - looks similar
(https://static.rapidonline.com/catalogueimages/product/s26-5864p01wl.jpg)
No comment on the third one I posted?
i know there was a vid by "voltlog" testing meter fuses from another company that used test currents and timed the speed it tripped.
It appears it came with the the Keysight meter.
I bought the Keysight meter from Keysight, brand new. Yes I unboxed it and proceeded to test it to failure. Very few meters I have looked at came with SIBA branded fuses. Most that did, used the small body style. The Keysight meter I bought did have a 10A large body and I had pulled the fuses when I scrapped the meter. The pulled fuses get tossed into a bag. There is only one 10A SIBA fuse in the bag. But, I've ran many meters over the last couple of years and it's possible there was some other meter that came with SIBA branded fuses that I scrapped. So I use the word appears because there is a chance that it came from something else. I'm not sure what I would have done with the fuse from the Keysight though.It appears it came with the the Keysight meter.
What do you mean by "appears"? Did you personally unbox a new/sealed Keysight meter and remove that fuse from it?
i dont think breaking them will tell you much, even if they are fake they can still be sand-filled.If you take the time to watch those videos you linked and read the comments, you will find he based those tests off of mine. He had some problems with the first setup and you will see where I posted some details to try and help him sort it out.
i know there was a vid by "voltlog" testing meter fuses from another company that used test currents and timed the speed it tripped.
No comment on the third one I posted?
I'm not sure about that one. On the one hand I don't see why SIBA would have two types of markings but on the other I know that when you make a comment like that it's a trap.
There's a distinct lack of pictures of fuses on SIBA's web site to compare anything with. :-//
I bought the Keysight meter from Keysight, brand new. Yes I unboxed it and proceeded to test it to failure. Very few meters I have looked at came with SIBA branded fuses. Most that did, used the small body style. The Keysight meter I bought did have a 10A large body and I had pulled the fuses when I scrapped the meter. The pulled fuses get tossed into a bag. There is only one 10A SIBA fuse in the bag. But, I've ran many meters over the last couple of years and it's possible there was some other meter that came with SIBA branded fuses that I scrapped. So I use the word appears because there is a chance that it came from something else. I'm not sure what I would have done with the fuse from the Keysight though.It appears it came with the the Keysight meter.
What do you mean by "appears"? Did you personally unbox a new/sealed Keysight meter and remove that fuse from it?
I bought the Keysight meter from Keysight, brand new. Yes I unboxed it and proceeded to test it to failure. Very few meters I have looked at came with SIBA branded fuses. Most that did, used the small body style. The Keysight meter I bought did have a 10A large body and I had pulled the fuses when I scrapped the meter. The pulled fuses get tossed into a bag. There is only one 10A SIBA fuse in the bag. But, I've ran many meters over the last couple of years and it's possible there was some other meter that came with SIBA branded fuses that I scrapped. So I use the word appears because there is a chance that it came from something else. I'm not sure what I would have done with the fuse from the Keysight though.It appears it came with the the Keysight meter.
What do you mean by "appears"? Did you personally unbox a new/sealed Keysight meter and remove that fuse from it?
I had made a series of videos where I modified a UT61E. One of the things I had done was to replace the small fuse with the larger one using this SIBA fuse. However, later changed out the shunt to allow using the meter at 20A and replaced the 10A fuse and back into the bag it went. I can't seem to find any other videos showing the 10A fuse and am fairly confident of it's history.
https://youtu.be/d6LTsaOqk30?list=PLZSS2ajxhiQDrk4o1Y45auwK7LomjnNBU&t=274
No comment on the third one I posted?
I'm not sure about that one. On the one hand I don't see why SIBA would have two types of markings but on the other I know that when you make a comment like that it's a trap.
There's a distinct lack of pictures of fuses on SIBA's web site to compare anything with. :-//
Here are the original SIBA HRC 10kA fuses that came with my U1273A purchased new.
The printing is radically different between them.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=656295;image)
At home I will check the Fluke ones I got many years ago (11A and 440/1000). I wonder if their printing is equally uneven.
dont Fluke use LittleFuse? i think LittleFuse use printed labels stuck to the fuse.
Looking at photos of the new ones I have looked at, the larger style fuse appears to be Mexican made Bussman's with a printed label and woven tube. Some of the very old Flukes I've looked at had USA made Cooper Bussman Limitron's in them. These also have a printed label and woven tube.At home I will check the Fluke ones I got many years ago (11A and 440/1000). I wonder if their printing is equally uneven.
dont Fluke use LittleFuse? i think LittleFuse use printed labels stuck to the fuse.
Yes, that is the 44/100 I have here (the 11A is gone)Looking at photos of the new ones I have looked at, the larger style fuse appears to be Mexican made Bussman's with a printed label and woven tube. Some of the very old Flukes I've looked at had USA made Cooper Bussman Limitron's in them. These also have a printed label and woven tube.At home I will check the Fluke ones I got many years ago (11A and 440/1000). I wonder if their printing is equally uneven.
dont Fluke use LittleFuse? i think LittleFuse use printed labels stuck to the fuse.
One thing I never understood is how they get away with putting a fuse only rated for 10KA in a CAT III and up meter? I don't know of many fast blow fuses besides these from SIBA that are rated to 30KA.
I was going to say that there's a video of a guy at fluke connecting a meter to 660V and twisting the selector dial back and forth, but AFAICT it's a meter with no current ranges:
I was going to say that there's a video of a guy at fluke connecting a meter to 660V and twisting the selector dial back and forth, but AFAICT it's a meter with no current ranges:
:-DD :-DD
I watched that AEV (AVE?) video where he looks at the non-contact Fluke fork and rants about how bad it is for an hour while trying to use a current monitor with it. Lots of drama and just stupid. Then I see him post about a cheap meter and compares it with a Fluke. No big deal but he is talking about how safe the Fluke is, all the while with some fuse that he pulled from the local hardware store stuck in it. If you are going to promote safety, seems like you would at least use a fuse rated for the AC/DC voltages and proper break currents.... |O
I make mistakes in pretty much every video I put out but IMO these go beyond a simple mistake.
Also, curious what would happen if this blew the supply company's service fuse? What would they charge to come out and fix it? And would they ask how it got blown?It's pretty common here. You can buy a 63A fuse and install it by yourself if you dare. Fuse box doesn't have any precinct. Just a plastic lever inside.
I was hoping to finish up my testing this weekend for the new meter but ran into a minor setback. Parts are on order and should make it in next week.
I was hoping to finish up my testing this weekend for the new meter but ran into a minor setback. Parts are on order and should make it in next week.
It died much too early?
you don't want me to spoil it for you, do you?
At least we agree on the correct choice of calculator. :)
Edit: Real SIBA fuses? The printing on them looked nice in the video, maybe some closeup images.
(or ware those the fuses you posted the other day?)
Hey seems that the DMM have some similar cousins,.. Kyoritsu KEW 1062 :
https://www.kew-ltd.co.jp/en/products/detail/00976/ (https://www.kew-ltd.co.jp/en/products/detail/00976/)
Copy cat?
What's that capacitor doing there?
What's that capacitor doing there?
I believed is being measured by the meter, a 25uF part, before it gets totally assembled , clean and dry. This way you wont get more surprises to avoid further taking apart
After several of hours of tracing all these analog switches and multiplexers, I now know way more than anyone should ever have to about the TY720.I feel your pain. I started to extract the schematics of the Surpeer AV4 and suddenly the same thought came to my mind. I then closed everything and sold it for the same price I paid (with all the proper disclaimers, of course).
After several of hours of tracing all these analog switches and multiplexers, I now know way more than anyone should ever have to about the TY720.I feel your pain. I started to extract the schematics of the Surpeer AV4 and suddenly the same thought came to my mind. I then closed everything and sold it for the same price I paid (with all the proper disclaimers, of course).
Did you also touched some solder joints? they look very shinny.When it was all said and done, I had removed and reattached 13 ICs and several other parts. I did blend in some 60/40 on the tabs for the shield to lower the temp. The rest, I just added flux and reflowed the parts. My PACE tweezers and heat gun were getting a work out.
Watched the video but you only touched on the real issue... it was a fuse, but it wassn't one of the two main fuses? Or was it? You have us all in suspense :-DMM ???
The meter did have what appeared to be a defective SIBA branded fuse that I replaced early on. I don't feed the transients into the current inputs of the meter so no, the damage to the capacitance mode had nothing to do with my changing out that fuse. That was a completely separate problem.
Normally on the better class of meters, the high speed clamps will fail and save the down stream components. On the low end meters, normally something else in front of the clamp (normally the PTC) will brake down and it's game over. In this case, the entire front end checked out. This may be a first. It also tells me that the meter could use some improvements. It has enough other problems that it's hardly worth spending more time on though.
Here is another Japanese meter that may look interesting:
https://overseas.sanwa-meter.co.jp/items/detail.php?id=13 (https://overseas.sanwa-meter.co.jp/items/detail.php?id=13)
It has nano siemens at least :P but the contrast seems a little dim from the catalog and pictures.
[Edit]
Not a newer model for sure.... it has been reviewed and digits are more slim but not too dimmed . Capacitance reading is quite fast
I think that one is based on Brymen BM867. It even uses same pc cableHey you're right, layout is nearly identical, except Sanwa PC7000 has a temperature setting on the rotary.
.
Spotted in another thread:
A poor little Brymen being asked to check the EHT voltage in a Tek CRO. :scared:
Only a couple of times its rated voltage. :-DD
Recommended, NO. Impressive YES !
I sense that Kyoritsu/Yokogawa designed that meter to be built with low cost parts and low-cost labor (Thailand) to maximize profit.
AFAIK Hioki is the only Japanese brand that still make their meters in Japan with their own ICs. Hioki LCDs seem to have the best readability from extreme vertical angles (from below and above).
I sense that Kyoritsu/Yokogawa designed that meter to be built with low cost parts and low-cost labor (Thailand) to maximize profit.
AFAIK Hioki is the only Japanese brand that still make their meters in Japan with their own ICs. Hioki LCDs seem to have the best readability from extreme vertical angles (from below and above).
I doubt there is much labor in these meters once the the line is setup. They may have just wanted a design they could maintain. Akira Tsukamoto would need to chime in.
Personally, the display that for me has been the most memorable is the UNI-T UT181A. That color just pops. The worst display I have seen was by far my old Fluke 97 scope meter.
The newer meters with TFT or OLED displays look phenomenal compared to the standard LCD... I also like what Aneng did with their Q1, with reverse backlit LCD. I know Dave doesn't like it but I sure do.
The newer meters with TFT or OLED displays look phenomenal compared to the standard LCD... I also like what Aneng did with their Q1, with reverse backlit LCD. I know Dave doesn't like it but I sure do.
The newer meters with TFT or OLED displays look phenomenal compared to the standard LCD... I also like what Aneng did with their Q1, with reverse backlit LCD. I know Dave doesn't like it but I sure do.
You must hate batteries.
Thanks a lot for the syncing ,no need to explain more ... i perceived wrongly "have" from "haven't" on the Yokogawa update video and kept the wrong idea all the way over and over, :palm:
Thanks a lot for the syncing ,no need to explain more ... i perceived wrongly "have" from "haven't" on the Yokogawa update video and kept the wrong idea all the way over and over, :palm:
You may have indeed misunderstood and had the wrong ideas but I have no clue where you came up with that 1.5X factor or what you were showing with that stop watch. It was pretty obvious the settling times were not effected as I had explained.
Since i got confused i may crystallized the idea and tried between the two videos find the difference. The start point is the same but stop is wrong because stopped when you started talked about the values and that made the difference. Yeah insisted in the wrong ideia.... blinding the obvious... |O
If that's the expire date then expect the worse :P They all may leak... at least its written on the back of the casing. The OLED in the Q1 doesn't seem quite good compared to an 8008, doesn't mean that other OLED based meters are worse for example the Agilent / Keysight U1253A looks very nice... but remember power hungry display :PMalagas, just keep in mind the Q1 is not OLED but instead a reverse plain LCD.
Oppss it's even worse??? I thought it was an OLED LCD :P 5 years is a young meter as long as you don't expose much heat, it will last more years. Currently working with two U1251 A /B models at work and one (A) of them has the plastic of the rotary switch ripped off ( maybe too exposure to sunlight).Sunlight and heat destroy anything. Last summer I was fixing my pool equipment and my trusty Fluke 27/FM was under the sunlight for about 15min or so. It was facing down when I was not using it, so the LCD wouldn't become dark but, even still, its display became faded. It only came back to normal when I reseated and cleaned the zebra strips.
One thing i've noticed at home during some experiments with electronics using AC 230V with isolation transformer, the meters BM235 e UT139A measuring V / A ( vice-versa) of the circuit. would display OL when mangled the contacts from old plugs. it does create arcs and maybe AC transients in lower energy (about 6VA ) and trigger the OL situation on the meter. It doesn't matter if i swap the meters for A and other for V . To disable the OL of course it is required to turn off. the units.I suspect the arcs may be shooting the voltage to very high levels. That or the meters are susceptible to high frequency transients.
I didn't repeat the experience to avoid any potential damage to meter or DUT or even me and used better plugs.
is this some sort of protection implemented on the meters?
Oppss it's even worse??? I thought it was an OLED LCD :P 5 years is a young meter as long as you don't expose much heat, it will last more years. Currently working with two U1251 A /B models at work and one (A) of them has the plastic of the rotary switch ripped off ( maybe too exposure to sunlight).Sunlight and heat destroy anything. Last summer I was fixing my pool equipment and my trusty Fluke 27/FM was under the sunlight for about 15min or so. It was facing down when I was not using it, so the LCD wouldn't become dark but, even still, its display became faded. It only came back to normal when I reseated and cleaned the zebra strips.One thing i've noticed at home during some experiments with electronics using AC 230V with isolation transformer, the meters BM235 e UT139A measuring V / A ( vice-versa) of the circuit. would display OL when mangled the contacts from old plugs. it does create arcs and maybe AC transients in lower energy (about 6VA ) and trigger the OL situation on the meter. It doesn't matter if i swap the meters for A and other for V . To disable the OL of course it is required to turn off. the units.I suspect the arcs may be shooting the voltage to very high levels. That or the meters are susceptible to high frequency transients.
I didn't repeat the experience to avoid any potential damage to meter or DUT or even me and used better plugs.
is this some sort of protection implemented on the meters?
Some meters, even from reputable manufacturers such as HPAK, showed this behaviour. The major issue is that there are usually several tradeoffs when designing the input section of a multimeter: safety level, noise/sensitivity, bandwidth...
This is only solved by a very good and well tested design.
I have a Brymen BT-75 voltage tester. It works great. It will auto switch on when you connect tips for continuity test. It will actually auto switch on when you probe few hundred kiloohms.
It has dark case. I left it in the sun last summer. The PTC based low Z circuit in front end heated enough for it to start leaking enough to switch on tester just laying there in the sun.. Still works normally but kept switching on by itself.. So back in the toolbox it went..
Sun is strong here...
Spotted in another thread:
A poor little Brymen being asked to check the EHT voltage in a Tek CRO. :scared:
Only a couple of times its rated voltage. :-DD
Recommended, NO. Impressive YES !
:-DD :-DD :-DD I continue to abuse the little pocket Brymen that member True posted about. After everything I have done to this meter, it would be fun to take Dave's SANWA and have my own shoot out. A badly abused Brymen vs a brand new Sanwa. :box:
Original poster of the BM22s torture. It got up to around 2Kv then made some unpleasant noises, i assume the spark gaps going in it. I let it go for a few seconds. No measurement problems or damage afterwards I could identify.
Also indeed recommended no, but I didn't fancy putting the 87V near that one and the proper 40Kv probe was buried in the back of the junk cupboard somewhere. Seeing as I have five of these BM22's now (I get them free every time I buy something Rigol) I figured I'd see what it was capable of.
Incidentally no I wasn't in contact with the device while testing. That would be insane. I actually soldered the probe tips to the HT parts of the board and powered up remotely.
They are very handy little meters. I pop one in my pocket every time I go to a hamfest to test things before I buy.
I think it’s more I’d cry if I blew up the 87V. If the BM22s blew up I’d throw it in the bin and get another one out :-DDYour post is a testament to Brymen's robustness.
Joe, you'd give Dave recursive nightmares about spitting on contacts.. then again, he's a rock that probably sleeps like one :-DD
Engineers are incredibly easy to shut up, they deal in facts, just show them concrete data and it's done.
If you don't have concrete data to show your device works and/or is practical, then it's not unexpected for people to call you things when you work in this sort of field. Because there are countless crackpots and tesla-nuts out there, the internet is filled with them, and many startup companies have stolen a lot of peoples money. People have good reasons to be very skeptical.
I think it’s more I’d cry if I blew up the 87V. If the BM22s blew up I’d throw it in the bin and get another one out :-DDYour post is a testament to Brymen's robustness.
I keep my first LeCroy DSO for that same reason. When it comes to the handhelds, I have no problems abusing them for the benefit of others. It's really their main purpose. I had ran a long term high voltage test on the 87V to show the effects on the MOVs. I didn't take it up to the same voltage level you have.
https://youtu.be/dQPcAs0EEqY
I think it’s more I’d cry if I blew up the 87V. If the BM22s blew up I’d throw it in the bin and get another one out :-DD
I think it’s more I’d cry if I blew up the 87V. If the BM22s blew up I’d throw it in the bin and get another one out :-DDYour post is a testament to Brymen's robustness.
I keep my first LeCroy DSO for that same reason. When it comes to the handhelds, I have no problems abusing them for the benefit of others. It's really their main purpose. I had ran a long term high voltage test on the 87V to show the effects on the MOVs. I didn't take it up to the same voltage level you have.
WRT the 87V, I tend to treat the HRC fuse, MOVs etc as "last resort". That's what will stop you getting toasted on a transient or a stupid error. For daily use I expect them to work ONCE to save my butt. That's worth a new meter. New me is not an option. I don't care if they survive or not.
In the past, I have had to test some of my designs for vibration. These were typically larger/heavier than a handheld meter and I would suggest a more harsh environment than a typical meter would ever see. I am thinking I may try to come up with some sort of simple test jig to run a few meters on and may start with this little pocket meter. I suspect mostly they see the drop or maybe low frequency low displacement. I have not found any standards yet that companies have followed.
Some of those standard's may be listed in the PDF here: http://www.sci-lab.com/2743-01.pdf (http://www.sci-lab.com/2743-01.pdf)In the past, I have had to test some of my designs for vibration. These were typically larger/heavier than a handheld meter and I would suggest a more harsh environment than a typical meter would ever see. I am thinking I may try to come up with some sort of simple test jig to run a few meters on and may start with this little pocket meter. I suspect mostly they see the drop or maybe low frequency low displacement. I have not found any standards yet that companies have followed.
There are vibration standards for both ground (truck/rail) and air transport (the transportation of the product is a necessity and known quantity, unlike end-user requirements). I used to test gear against this with custom jigs, but it was a long time ago so don't recall the standards off-hand.
I used to work for a company that had a magnesium table for vibration testing (http://www.sci-lab.com/SLvibration.php). I guess that's gotta be the duck's gut's for stress, but how do you plan to integrate this into your already detailed scope of tests?We had similar tables, some that were the floor of the environmental chambers. It's a bit overkill for the home lab. :-DD
For those vivration tests, I would love to see how Fluke tests a meter such as the 28 II EX - I heard it is potted inside.
I can see the posts now, "I've owned that meter for 10 years and its never had a problem. " :-DD :-DDYes, I think this is a great exercise but, differently than your rotary test or even the transients, it is much harder to translate a constant vibration pattern to a real world scenario. A constant vibration table seems closer to leaving the meter on top of a car's engine or the washing machine in a cycle spin, but it can barely translate to the G forces subjected by falls, for example.
I can see the posts now, "I've owned that meter for 10 years and its never had a problem. " :-DD :-DDYes, I think this is a great exercise but, differently than your rotary test or even the transients, it is much harder to translate a constant vibration pattern to a real world scenario. A constant vibration table seems closer to leaving the meter on top of a car's engine or the washing machine in a cycle spin, but it can barely translate to the G forces subjected by falls, for example.
However, we do what we got to do.
I can see the posts now, "I've owned that meter for 10 years and its never had a problem. " :-DD :-DD
It will of course be very interesting to see vibration tests on different multimeters and especially Flukes. Because they have removed the "Vibration" and "Shock" heads from the specifications of their multimeters in current revisions. Either they feel no more confident or the requirements have gone more stringent.From the Fluke 189 manual:
It is required to do a pause between frequency ranges while testing?Like the transient testing, I am loosely using the standards as a guide. I provided a link to the standard if you would like to read it. I suggest section 4.5.5.3.2. At this time, I plan to run a linear sweep that follows that profile. Maybe run 3 cycles, up and down, half hour per cycle. I have no plans to search for resonance. I'll just let it run and do a before and after functional test and inspection. I am also thinking to just run it in the one axis, backside down, rather than to look at all three. It's all up in the air for now until I actually try running a few meters.
Thanks for the info related to the standard and the go to. Hope the needle of that Multimeter survives :PIt was a fairly inexpensive meter and has a bit of weight to it compared with the pocket meter.
This reminds me of the first meter I blew up. A Micronta 212. I might buy one off ebay if I see one cheap to see if I can recreate that moment on video. The entire meter front filled up with smoke and the needle fell off after leaving it on the 15V DC range and poking a 300V AC HT secondary on a valve radio transformer. :-DDThis could be the victim.. >:D https://www.ebay.co.uk/itm/Radio-Shack-Micronta-22-212-multimeter-works/123706889646 (https://www.ebay.co.uk/itm/Radio-Shack-Micronta-22-212-multimeter-works/123706889646)
***Joe, I added the high resolution photos on the video's description, including the rotary switch.
Watched his last video. Would have liked to have seen the PCB removed so we could see the switch contacts. I suspect it just uses the single PTC and some transistors for the clamp. Maybe a TVS in there. I doubt it would do very well in my transient testing.
Joe, I added the high resolution photos on the video's description, including the rotary switch.Thanks for adding them. Looks like the same old problems we have come to expect. The UT139C didn't make it as far in the transient tests as the Amprobe AM510, which is a bit strange as both are UNI-T products. Still, it's more robust than most of their products and AT LEAST it survived that little grill starter that seems to be famous for damaging them. The difference I see between the 139C and the 510 is that I damaged two 139Cs that could not be repaired. In the case of the 510, I was able to repair it. One goes to the recycle, the other lives to run another test.
As you imagined, it is an ordinary meter in terms of safety and rotary switch design.
The UT139C that I am still editing is much more promising. I know you tested it up to 5.1kV, which to me is quite impressive (similar to the much more expensive Keysight U1231A)
Does it ever become stable? Those are some big jumps.
The leads will add capacitance. Seen some that will read zero with the leads installed, like that Yokogawa for example. Just depends on the meter.
Quite interesting. I don't know the AM510, but the UT139C I have is an off-brand and seems to have a much heftier protection when compared to the Surpeer, the Mestek and my chinese-targeted UT-61E (the one with the PCB that looks like suitable for TÜV mark but has gobs of unpopulated MOVs and PTCs).Joe, I added the high resolution photos on the video's description, including the rotary switch.Thanks for adding them. Looks like the same old problems we have come to expect. The UT139C didn't make it as far in the transient tests as the Amprobe AM510, which is a bit strange as both are UNI-T products. Still, it's more robust than most of their products and AT LEAST it survived that little grill starter that seems to be famous for damaging them. The difference I see between the 139C and the 510 is that I damaged two 139Cs that could not be repaired. In the case of the 510, I was able to repair it. One goes to the recycle, the other lives to run another test.
As you imagined, it is an ordinary meter in terms of safety and rotary switch design.
The UT139C that I am still editing is much more promising. I know you tested it up to 5.1kV, which to me is quite impressive (similar to the much more expensive Keysight U1231A)
Yet another edit to my table at:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013)
Added the Mestek DM91A and the UT139C.
The UT139C comes really close to the ICL7106. Interestingly, the backlight of these two is really low power.
This is mentioned at the bottom of the tableYet another edit to my table at:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013)
Added the Mestek DM91A and the UT139C.
The UT139C comes really close to the ICL7106. Interestingly, the backlight of these two is really low power.
Curious how nom. current was measured, as I noticed current draw varies by what measurement setting the multimeters is in, with highest draw usually happening in resistance, diode test or continuity modes.
Yet another edit to my table at:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013)
Added the Mestek DM91A and the UT139C.
The UT139C comes really close to the ICL7106. Interestingly, the backlight of these two is really low power.
IMO, non-autoranger's need separate power switches. On the 133A, common functions are 4-6 clicks away from OFF.. FAIL!!
There is another alternative to Mestek DM91A but with less resolution counts ( 6000) , the Uni-t 133A which is a compact true-rms meter witn NCV:What attracted me to the DM91A and made me call it "Aneng killer" was the price/feature ratio: at a sale on the Banggood site, it was US$16.00 with free shipping, which was less than the Aneng 8008/8009 and much better featured. However, we don't know how this trend will go, as the Anengs were also much less expensive than their current price when they were released (IIRC).
http://www.uni-trend.com/index.php?m=content&c=index&a=show&catid=172&id=192 (http://www.uni-trend.com/index.php?m=content&c=index&a=show&catid=172&id=192)
It costs around 30E on local market with shipping + 2Y waranty and should be cheaper on other market platforrms
Stupid Uni-T does no favours in completely confusing their product families.IMO, non-autoranger's need separate power switches. On the 133A, common functions are 4-6 clicks away from OFF.. FAIL!!That's the model 133B you're refering, the 133A is automatic.
Stupid Uni-T does no favours in completely confusing their product families.
How is anybody supposed to buy a Uni-T if they know that there's two or three identical-looking variants out there but some don't have any input protection inside?I agree, but I can tell the wide variance of quality and assembly across the Anengs, Mastechs, etc does not leave much to desire. Well, perhaps you could make the case these brands still actually mount the parts on the board, regardless of the Shenzhen sale of the week.
The uni-t 136C looks like a compact multimeter , two off positions , simple switch ( not like the 133A here HZ in the mV, bugger ), there is some space that could fit more protection . One of the fuse is glass and other is ceramic on the older picture, which may lead that the original has been tested :P (just kidding) A little bit of flux residue is also present, near the push buttons. Nice digits (Edit)IIRC I had blown one of the fuses and grabbed whatever I had on hand.
Correct if im wrong but Most of the new meters beep on anything , eg rotary switch, buttons, power going off, they should have an option to mute beep except on continuity .Most of the chinese ones, at least. The Brymens and the Flukes and Keysights are quite silent, depending on the model. All of them beep when entering auto power off and the Keysight U1281A/U1282A have two settings for beeps: beep for everything or beep only for continuity/input alert/NCV.
The Mestek it is a good alternative, looses the splitted jack for the mA , but at least NCV has the antena functional and visible, has well other functions.That is what is so hard about the Mestek: if it had better input protection, it would be a great all around meter for small jobs around the house:
The Mestek it is a good alternative, looses the splitted jack for the mA , but at least NCV has the antena functional and visible, has well other functions.That is what is so hard about the Mestek: if it had better input protection, it would be a great all around meter for small jobs around the house:
- The NCV is really good, with the proper sensitivity to identify which side of the romex cable is carrying the live
- The capacitance is reasonable for HVAC systems
- The flashlight saved me from a few bad scenarios
- The 1.5V and 9V battery testers are quite handy
Fungus, using the meter I can tell it is slow only on continuity - the rest is quite on par with meters of the same class.The Mestek it is a good alternative, looses the splitted jack for the mA , but at least NCV has the antena functional and visible, has well other functions.That is what is so hard about the Mestek: if it had better input protection, it would be a great all around meter for small jobs around the house:
- The NCV is really good, with the proper sensitivity to identify which side of the romex cable is carrying the live
- The capacitance is reasonable for HVAC systems
- The flashlight saved me from a few bad scenarios
- The 1.5V and 9V battery testers are quite handy
Downsides:
* Basic accuracy isn't very good (0.7% DC voltage)
* It's a bit slow at everything (eg. continuity tester is awful, it takes ~3s to measure a 100 Ohm resistor)
* If you're not interested in AC mains the the first two stops on the selector will annoy you every time you have to click past them.
* It's not small
As for the beeping the U1282A if not turned off its a bit anoying at work :P The U1252A/B are definitly more silent and quite good to work. Brymen doesn't beep as much but has a loud beep :P Fluke its tolerableMy U1282A is beeps hysterically when the switch range goes to the µA/mA/A ranges, with or without probes connected anywhere on the meter. Does yours do that as well? It is quite an annoying behaviour.
I'm pretty sure the design is modeled on the "Transformers" movie franchise.
Found a rather comical DMM testing guy (https://youtu.be/V-vBcCKk2NI?t=418) on YT this evening.. he says he's got a bunch of items on order for new reviews, so I subscribed for the variety. I was also surprised the 10,000 count Mestek DM91a (https://www.ebay.com/itm/MESTEK-DM91A-Handheld-LCD-Digital-Multimeter-9999-Counts-Manual-Ranging-Tool/253970570733) can sell for just $16.51 on flea-bay.
I said he was comical.. ??? but obviously not at your level. IMO I like it when someone else (not me) shells-out coin for these iffy DMM's to give me PCB shots so I can make my own judgments. Now an old pro wouldn't be jealous, would you? :-DDI think he said he was in IT and they used that meter for service work, some story like that.
Correlation: He spends $$, we see the guts in what we shouldn't buy in the first place. I don't recall anything about 10,000 switch cycles.. if I saw his comments prior, I obviously didn't think it was worth remembering.. some things aren't ;)
Here you go!! I have started a new poll where you have a chance to voice your opinion about continuing these tests.
You may enjoy watching the next video. You're big on the drop and vibration tests. I plan to use that poor man's vibration table as part of my testing. I'm sure those speakers were not designed for what I am doing with them....Here you go!! I have started a new poll where you have a chance to voice your opinion about continuing these tests.
Zap 'em! Grind 'em! Lick 'em to death!
I plan to use that poor man's vibration table as part of my testing. I'm sure those speakers were not designed for what I am doing with them....
Not all meters were completly destroyed but yeah damaged by the tests and the very good part (Edit terrible english sorry ) was they where able to be repaired which all bonds to all work one here. There's also the third option. Take to an ESD or IEC certification lab for testing :PA very low percentage of the meters I have looked at were able to be repaired. Most go to the recycle bins. That's one of the main differences I see with these low end meters, they are disposable. I may damage the higher end meters but they have normally paid enough attention to the details to where the controller IC is not damaged and I have been able to repair them. Maybe 30%.
I plan to use that poor man's vibration table as part of my testing. I'm sure those speakers were not designed for what I am doing with them....
Ever heard of buttkicker transducers? Might be just the ticket if those speakers aren't sufficient... thebuttkicker.com
To rent time at a lab and have a product certified I would imagine is in the order of $20,000 or so USD. I really don't see that as being an option. Even if we didn't certify them, the rental costs would far exceed what I would be willing to spend. The we have the problem that I am not really interested in seeing the meters pass their safety standards or not. A lab like this will have generators specifically for running the IEC standards which is not at all what I have been showing.
This is normally preceded by a viewers comment about how I have shown how safe or unsafe a meter is, which obviously I don't.
To rent time at a lab and have a product certified I would imagine is in the order of $20,000 or so USD. I really don't see that as being an option. Even if we didn't certify them, the rental costs would far exceed what I would be willing to spend. The we have the problem that I am not really interested in seeing the meters pass their safety standards or not. A lab like this will have generators specifically for running the IEC standards which is not at all what I have been showing.
Opps i should clarify that the option was intended to the viewers , not for you to check, since you mentioned something about this matter in one or more the videos as a sugestion.
You like the meters that share the current with the voltage?I don't but $20 is small change. It's almost a pocket meter, IMO.
I best not shake my Mastech meter then. I think it has more pots than any of my working handheld meters.
I best not shake my Mastech meter then. I think it has more pots than any of my working handheld meters.
Please do include at least one multimeter of your choice with pots for calibration.
Does the masteech has many pots as this ut204A?It appears so.
What I saw on UT70C is that trimpot has too much of the adjustment range. Replacing it with combination of fixed resistors and much smaller trimpot would make much more stable in that regard.I have seen others post that as well. The two UT61E's I looked at, came with 2K trimmers. When I measured them, they were both set below 1K. So I replaced mine with a 1K. I was only looking to improve the temperature drift, which this change did nothing to help.
I have a few meters that have not gone to the recycle yet that I could strip the pots from to run a test like this.
Most of the meters I look at now do not have trimmers.Not for calibration, but they still might have frequency response trim in AC path..
At local market it currently selled the MS8229 which has luxometer, soundmeter, termometer , humidity. What about measuring sound dB with MS8229 off the vibration plate?Sells for about $50 USD. I am not sure what you are asking. Do you want to know the sound level of the plate? If so, do you just want the peak dBm and what frequency? Keep in mind that I have no way to know if the the meter is in calibration. It would be some relative number. Not sure how it would relate to anything.
Joe, interesting tests, but when you mentioned "Mother Nature" I thought you would also go the other side of 0°C. I was thinking the chances of survivability of a DMM on a cold weather are much higher than on sunny hot weather. The obvious first casualty would be the LCD, thus it would have to be protected from direct sunlight. I imagine the second casualty would be the plastic enclosure, which depending on the material it will be affected by the UV.
Summer is coming and maybe I get one of these and try to do a test here. With the temperatures we can reach here in Texas (sometimes we get +40°C in the shade), I suspect the little Brymen/Amprobe would not fare as well. I could also leave it in the attic, where temps easily reach +45°C (maybe more).
Oh well... thanks again for the video and keep on burning them!
Yes, the wide variance in temperature would have a very extreme effect as well. However, I have no idea what would be the survivability rate of a meter inside a car during summer - in the worst days it can reach 55°C.Joe, interesting tests, but when you mentioned "Mother Nature" I thought you would also go the other side of 0°C. I was thinking the chances of survivability of a DMM on a cold weather are much higher than on sunny hot weather. The obvious first casualty would be the LCD, thus it would have to be protected from direct sunlight. I imagine the second casualty would be the plastic enclosure, which depending on the material it will be affected by the UV.
Summer is coming and maybe I get one of these and try to do a test here. With the temperatures we can reach here in Texas (sometimes we get +40°C in the shade), I suspect the little Brymen/Amprobe would not fare as well. I could also leave it in the attic, where temps easily reach +45°C (maybe more).
Oh well... thanks again for the video and keep on burning them!
It doesn't get very warm here during the Fall to Spring months. Having it sit in the car during the mid Winter months, the meter goes from a very cold temp to toasty and back to cold in a short time.
My cars and bikes use LCDs in their instrument clusters. The bikes have a back cluster. The cars will sit in the sun with their windows up. I have not seen an LCD fail in these conditions.Yes, I haven't either in my car and its LCD clusters, but none of them are in direct sunlight exposure. Leaving my ancient Fluke 27 or any other more modern meter facing the sun starts with a rainbow effect and culminating with a complete blackout.
It would be interesting to have someone else try and replicate True's findings. The claim was five of these all failing the same? I would have expected that after everything I have exposed this one to that it would have been damaged. True and his friend must have some magic combination.I kinda lost interest after he/she stopped responding. To our benefit, you kept pushing and came with a very interesting series of tests after that.
As commented this was cryogenics for multimeters :P Currently have a TI 89 which had some corrusion, got cleaned with flux, new solder joints, powered up with 4xAAA no backup working, oven and 1 week on inside the car on summer for reflow :P, i believe 3 years ago. It is still working except for the backup battery. IMother nature took care of if. :PSorry. I don't understand your vibration sound test. I assume you are planning to make a stirring system but I am guessing where I am used to seeing a rotating part, you plan to do something that will viberate. I am not sure how MEMS technology fits in but guessing you plan to use the microphone to measure the sound level. You will need to know displacement at that frequency. Then somehow you will use this to compare against some other vibration system?
About the vibration tests, planing to do a simple stir starter using a microphone instead of mems to check frequency peak only, eg using audacity or sox,
About battery testing :P here's a hint as attachment for creating dummy's
The picture appears like you are attempting to mold some pawn chess pieces. Are you suggesting I make a mold to produce some dummy batteries? If so, it may be easier for me to turn a few parts on a lathe.
About the mold it's a thing about a post when i told was gonna perform some battery measurements on multimeters and publish the results. Tried first atempt with aligator clips but they pose lots of losses. , so decided to use a mold recreating shapes made of hot glue (chess pieces), to plan in the future make batery with glued contacts and proper wire to mate the DMM.
About the mold it's a thing about a post when i told was gonna perform some battery measurements on multimeters and publish the results. Tried first atempt with aligator clips but they pose lots of losses. , so decided to use a mold recreating shapes made of hot glue (chess pieces), to plan in the future make batery with glued contacts and proper wire to mate the DMM.
Your DMMs must draw a lot of current for you to measure lots of drop with an alligator clip.
What does your liquid shaker system have to do with meter testing?
About the mold it's a thing about a post when i told was gonna perform some battery measurements on multimeters and publish the results. Tried first atempt with aligator clips but they pose lots of losses. , so decided to use a mold recreating shapes made of hot glue (chess pieces), to plan in the future make batery with glued contacts and proper wire to mate the DMM.
Your DMMs must draw a lot of current for you to measure lots of drop with an alligator clip.
What does your liquid shaker system have to do with meter testing?
The DMM used in question was the ut204A clamp meter which draws 7.91mA in clamp meter mode DC current, and a voltage drop from 9.25V to 9.15V is presentented between battery and terminals using that piece of crap aligator clips , very thin wires :(
As said was reusing the idea of a speaker for another project , forgot to mention that is not directly related to meters. :P
a voltage drop from 9.25V to 9.15V is presentented between battery and terminals using that piece of crap aligator clips , very thin wires :(
Malagas, the super cheap alligator clip sets similar to the one on your photo are very low quality. I have some others that have been resisting quite well the test of time.
It is entirely related to the quality of yhr plastics and, obviously, the assembly. Most of them are just badly crimped - I usually solder them after the purchase.
This reminds me of the first meter I blew up. A Micronta 212. I might buy one off ebay if I see one cheap to see if I can recreate that moment on video. The entire meter front filled up with smoke and the needle fell off after leaving it on the 15V DC range and poking a 300V AC HT secondary on a valve radio transformer. :-DD
To celebrate Andy's return, finally a video that has nothing to do with handheld multimeters.
is that me going insane again or did i see at 00:30 a HP band on the monitor? it is an external monitor to the lecroy 8500A or ethernet / USB connection on Desktop PC? By the way this model is easy to use as its predecessors?
Check out Flexible 360° Clip Mobile Cell Phone Holder Lazy Bed Desktop Bracket Mount Stand
https://ebay.us/UvAwdP
Looks like they are selling some UNI-T products now as well. That's a large markup.That IS some serious markup! For us that are "in the know", that would get two 101's before any of the foreign policy taxes taxes kick in.
https://www.harborfreight.com/professional-commercial-and-residential-multimeter-64021.html (https://www.harborfreight.com/professional-commercial-and-residential-multimeter-64021.html)
And what about screw pole testers with CAT II. Good for discharging bug zappers. capacitors, pry boxes, and open the mini rotary tool brush compartiment :P
Hi Joe
strange protections...
So we endure another cheap DMM video.. I've already been raked and baked :palm: so I'll just sit back to watch the fireworks..
*edit - wow! that fuse lit pretty fast. Joe beat me to the punch!
Hi Joe
strange protections...
I want to apologize to anyone who made the mistake of clicking on that link. Sadly, I can't control what people post in this thread. Maybe I can have Dave lock it as I doubt I will do very many more tests on handhelds.
I did however finally run the test for Mr Fungus.
https://www.youtube.com/watch?v=Bar4VLt9KFM (https://www.youtube.com/watch?v=Bar4VLt9KFM)
Instead of locking the whole thing, why not delete the off topic post instead?Hi Joe
strange protections...
I want to apologize to anyone who made the mistake of clicking on that link. Sadly, I can't control what people post in this thread. Maybe I can have Dave lock it as I doubt I will do very many more tests on handhelds.
Joe, Dave might be able to offer you the ability to lock your own thread.
One I started in the Supporters Lounge had a lock that i could apply should the thread get out of hand however i never used it for fear that I couldn't unlock it.
I suggest you discuss this option with Dave.
Instead of locking the whole thing, why not delete the off topic post instead?
Some lack of participation may be due to the inspiration you've freely given to all, including the feckless copy artist's who don't know their ass from a hole in the ground.. Also the instruments market doesn't seem to be taken seriously now, since the Asian market has been dumping unsafe crap everywhere. I think we're all suffering fatigue with new whiz-bang junk appearing every 90-days, it just doesn't stop. Whatever you decide, you have earned my respect.
Cliff, the channel has been in the decline for several months. It's hard to say if posting my test results had an impact outside of maybe selling a few meters for Brymen. My goals for this were always for my own personal interest, not to sell meters or make any money at it. In that respect, I am happy with the result.
I think you've helped move a few Uni-T's as well.
Anyhow the last few videos felt a little different from all your previous videos, starting with the Mother Nature Takes Her Turn (which was quite long and I didn't really understand this video). One thing I see is that videos featuring popular cheap Chinese meters do well, and anything with Fluke also seem to attract viewers.
I bought a few old Fluke 27/FM's that test out good. Lets just say that 8 good ones and one that doesn't work due to emotional issues from a battery leak is more than I need. Not sure what happened that I got 9 of these as one would have been good, 2 plenty. Classic TEA (test equipment anonymous) screed I suppose. One moment I'm looking at an Ebay sale screen and the next thing I know my fingers are shaking and I needed to buy them....anyway, I see you didn't test any 27/FM's and I have too many. Like to send you one or two to blow up if you haven't folded up your tent and called it a day yet.
About deleting if you want me to delete the things related to my battery tests or the chess pieces, since they are not properly standarized or fully tested please let me now. I'll do and again apologize for poluting this thread. I didn't put enought effort but i'd like to finnish the current measure for the ut204A using the dummy battery and try to learn with mistakes because this particular meter its a battery hogger .
I think people want cheap meter because they miss the bast shield arc events and slow camera :P but could be wrong....
I think you've helped move a few Uni-T's as well.
Anyhow the last few videos felt a little different from all your previous videos, starting with the Mother Nature Takes Her Turn (which was quite long and I didn't really understand this video). One thing I see is that videos featuring popular cheap Chinese meters do well, and anything with Fluke also seem to attract viewers.
The only UNI-T product I have had a use for was the UT210, as a DC current clamp. I'm certain I helped sell a few of these.
Obviously, the lest several videos didn't included new meters. A couple of them have been non DMM related. So I am sure you are not alone in feeling they were a little different from the previous ones.
On the Brymen pocket meter, I let the battery drain down a few times, tossed it outside for the Fall and Winter months, then subjected it to some vibration. You would really have to help me understand what you don't understand, if you want me to help.
I think you've helped move a few Uni-T's as well.
Anyhow the last few videos felt a little different from all your previous videos, starting with the Mother Nature Takes Her Turn (which was quite long and I didn't really understand this video). One thing I see is that videos featuring popular cheap Chinese meters do well, and anything with Fluke also seem to attract viewers.
The only UNI-T product I have had a use for was the UT210, as a DC current clamp. I'm certain I helped sell a few of these.
Obviously, the lest several videos didn't included new meters. A couple of them have been non DMM related. So I am sure you are not alone in feeling they were a little different from the previous ones.
On the Brymen pocket meter, I let the battery drain down a few times, tossed it outside for the Fall and Winter months, then subjected it to some vibration. You would really have to help me understand what you don't understand, if you want me to help.
The issues I had with the video were:
1. You mention in the intro you decided to buy an Amprobe PM55A to see if you can get it to fail in the same manner as an EEVBLOG member who bought a few of these, but don't mention what the failure was... I'm wondering what's the point throughout the video, and eventually I lose interest.
2. The title says Brymen BM27s but why are you testing an Amprobe?
3. You then discharge a battery and subject it to different environmental conditions... ok... but what are we looking for? Still don't understand the failure for which you're testing.
The link to the original video works. The link to True's original posting does not go back to anything related to his post. But the point is, it would be helpful to the viewer if all relevant information could be included within the video, and not have to have the viewer stop the video, go back to review another video or thread, before resuming in order to understand its content. I hope you take this as constructive criticism; I'm not trying to bash your video.The issues I had with the video were:
1. You mention in the intro you decided to buy an Amprobe PM55A to see if you can get it to fail in the same manner as an EEVBLOG member who bought a few of these, but don't mention what the failure was... I'm wondering what's the point throughout the video, and eventually I lose interest.
2. The title says Brymen BM27s but why are you testing an Amprobe?
3. You then discharge a battery and subject it to different environmental conditions... ok... but what are we looking for? Still don't understand the failure for which you're testing.
In the description, there was a link to True's original posts along with the original video. Had you watch the original video or followed the thread point to in the link, you would have known that the Amprobe rebranded this meter and they are one in the same.
Funny, I just watched the first minute and half of this video. I think you lost interest before that. :-DD :-DD
Funny, I just watched the first minute and half of this video. I think you lost interest before that. :-DD :-DDWhat makes you believe that?
2. The title says Brymen BM27s but why are you testing an Amprobe?
First 10 seconds:
Hello again
Some time ago I made a video on this Brymen BM27s pocket meter
This one happens to be sold by Amprobe with the part number PM55A
I assume that the people watching these videos have the ability and desire to learn more about the subject and will do their own research. Not to point out the obvious, but that's actually all this thread has been about, me doing a little research. No one is spoon feeding me this data. I'm sorting out the tests and running them on my own. I'm sure that's a foreign concept to a few people but I image for most people working in the technical sectors, it's a fairly common practice.
A bit late, but I can say, every Meterman PM55 or Amprobe PM55A I have has failed.
What happens:
- Auto mode freaks out and doesn't work (a short shows an unstable high resistance for example)
- Short detect mode shows shorted
- EF (power stick) mode works
- I can't remember what Low-Z volts does
- Hi-Z voltage works
- Diode mode acts like a short
- High ohms varies from not working to usually sounding the "shorted" beeper; IIRC high ohms will not give a stable reading
- Haven't tested current
What causes this?
The only similar thing I could find was a dying battery.
I purchased a new unit after my PM55A had failed, only to find a PM55 I gave to a friend also failed. I tested a PM55 I had and it too had failed. The replacement? Well, it tested good (testing 5V in auto mode, and shorting probes, that's it...); after a month when I went to use it to test a low voltage DC circuit again, it showed low battery ... and sure enough it failed too.
I'd like to fix them but have no idea where to start or what could have failed.
[UPDATE:]
Ok I finally found it buried much earlier in the thread. So... if that video was targeted only for those who have actively been following this thread since at least mid last year, then it would make sense. If you want to target the video to a more general technical audience, then it would have been helpful to maybe list the issues True mentioned in the thread, for which you were testing. I, for one, started watching your videos before I even joined EEVBLOG. Most if not all of them stood on their own, without the viewer having to wade through threads on a forum to understand the point of the video.
I did however finally run the test for Mr Fungus.
I'm guessing they were called diddle sticks long before my time.I know you already did the work, but to go directly to a specific post, right-click on its title and copy the link.
I forgot to add the last "/" to the TOC. It should all work now. Per Windsmurf's comments, obviously the links will only get you to the top of the page. You may need to hunt around a bit from this location to find what you are looking for.
Hi.
Nice work on the static links on the first post. It looks like a history . I have a question. Does it appear always whether the post you're reading? I can only see the links when i hit the print button .
Have also turned off the ad blocker but no effect just to be sure :S I'll attach an example of a print on pdf format so you can see. Again i could be doing something wrong or not seeing properly :P
the document is too big for attachment. here is the doc :
https://drive.google.com/open?id=1nuwirpJ9RUXKu3heGG4KU_P8TOJPNmTg
Enjoy
Also now I wonder what do those specs mean?
Also now I wonder what do those specs mean?
I explain about multimeter specifications here: https://lygte-info.dk/info/DMMTolerances%20UK.html
Usual they are only valid between 18°C to 28°C, for each degree outside you must add some more tolerance.
So, then for the Brymen 869s in the video, specs for the 500.00mV range is:
DC Voltage, 869s, 500.00mV, 5.0000V, 0.02% + 2d
And since this spec is for 50,000 count range, I think I need to drop the last digit from the 500,000 count readings shown in the video (is this correct?).
Since Joe is measuring 1.00mV (assumed), according to the spec, readings should be:
1.00mV x 0.02% = 0.0002mV, and add 2 counts of 0.01mV and you get 0.0202mV, or for the meter 0.02mV.
So to meet specs, the meter needs to show something between 1.020mv and 0.980mV... is this right?
Thanks for the tests provided. Did one of the meters have become drifted after the test, for example the owon B41?
Yes, but again only in a limited temperature range, Joe goes well outside that range.
Thanks for the tests provided. Did one of the meters have become drifted after the test, for example the owon B41?
They all returned to normal after a day.
Yes, but again only in a limited temperature range, Joe goes well outside that range.
Yes I understand that... and yet the meter stayed in-spec regardless of the out-of-spec temperature (and condensation) condition, which is impressive. I wonder if Flukes do as well... I'm guessing probably the industrial ones will (or maybe all?).
Ohh crap was the leads or input jacks ? Or is the default error message for anything bad ?
It did seem to fall out of the 20 count spec for some duration... I'm guessing due to the condensation? I wonder what parts are affected by it... I'm guessing an analog part like the PTC? Or more generally some current leak on the board in the analog input section. I bet some insulating coating on the board can eliminate the condensation effect.
Keep in mind that during the transition, all of the components may not track. That difference can cause a fair amount of error and is why the meter is allowed to stabilize for a half hour. There is a fair amount of air movement but even a half hour may not be enough to some of the meters to settle.
Put two thermometers outside, one in a glass of water the other in open air. One will respond slower. This delay can cause a fair bit of error and again is why I let them settle.
In the mV range the input impedance of a crap meter is a Meg. The PTC is about 1.5K. Say the PTC changes 100%. What's the total error it causes?
Old Fluke 189
So in your opinion, do you think the error is caused more by uneven temperatures of the components, and less by condensation's effects on the board?
When it comes to trying to solve problems, I find my opinions mean very little and data is pretty much everything. :-DD
There are a few easy experiments that could be ran if we needed to sort it out. The UT61E for example, drifted far worse. It may have been the worse I have seen. For less than the price of a coffee, I was able to tame it. Then again, I wasn't considering my time having a cost. If I did, the UT61E I have is worth a bit more than a standard one...
It's good to know that the TOC was a waste of time.
It's good to know that the TOC was a waste of time.
You'd mentioned this in many of your videos (also listed on post #1), so I guess it's an unbending rule ;D.
...A few good articles if you are interested:
http://www.grainger.com/content/safety-digital-multimeter (http://www.grainger.com/content/safety-digital-multimeter)
http://cp.literature.agilent.com/litweb/pdf/5990-4578EN.pdf (http://cp.literature.agilent.com/litweb/pdf/5990-4578EN.pdf)
http://faculty.riohondo.edu/jfrala/fluke_multimeters_-_abcs_of_multimeter_safety_multimeter_safety_and_you_application_note.pdf
(http://faculty.riohondo.edu/jfrala/fluke_multimeters_-_abcs_of_multimeter_safety_multimeter_safety_and_you_application_note.pdf)
Ohh crap was the leads or input jacks ? Or is the default error message for anything bad ?
Leads or Fuse error message pops up if you're not in the amps range dial with a lead in the amps input, or you're in the amps range and you have no lead in the amps input or you have a bad fuse.
I get that when I clean the input jack on my 189 with a Q-tip with too much rubbing alcohol, until it dries out. I think the condensation shorted the amps range input sensor.
Its interesting that the 189 specs have a very wide operating temperature range of -20°C to +55°CC, and even gives you a temperature coefficient for measurement at <18 °C or >28 °C. Such detail is probably one of the reasons Fluke has become a standard in U.S. Industry.
It did seem to fall out of the 20 count spec for some duration... I'm guessing due to the condensation? I wonder what parts are affected by it... I'm guessing an analog part like the PTC? Or more generally some current leak on the board in the analog input section. I bet some insulating coating on the board can eliminate the condensation effect.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=763911;image)
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=763917;image)
...A few good articles if you are interested:
Just FYI the 2nd and 3rd links didn't work for me.
By the way here is an update for the battery testing on the UT204A in the DC 40 Amp's. Now there are not much of losses to care about from the previous experience with garbage crocodile cables :S 0.75m2 + crimped terminals + banana jacks .. 3.333 Ohms between power supply and meter. better measure voltage on input jacks with uni-t 50b ..[EDIT] its 8.97V on input jacks so it is much lower... need more resolution :D but this is an improvement.
Ohh crap was the leads or input jacks ? Or is the default error message for anything bad ?
Leads or Fuse error message pops up if you're not in the amps range dial with a lead in the amps input, or you're in the amps range and you have no lead in the amps input or you have a bad fuse.
I get that when I clean the input jack on my 189 with a Q-tip with too much rubbing alcohol, until it dries out. I think the condensation shorted the amps range input sensor.
Its interesting that the 189 specs have a very wide operating temperature range of -20°C to +55°CC, and even gives you a temperature coefficient for measurement at <18 °C or >28 °C. Such detail is probably one of the reasons Fluke has become a standard in U.S. Industry.
It did seem to fall out of the 20 count spec for some duration... I'm guessing due to the condensation? I wonder what parts are affected by it... I'm guessing an analog part like the PTC? Or more generally some current leak on the board in the analog input section. I bet some insulating coating on the board can eliminate the condensation effect.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=763911;image)
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=763917;image)
One of the interesting things of the manual is there is no mention to water resistance and yes there were water resistant watches back then, but check in the Physical Specifications the humidity ranges , it seems to be high for it's time as i repeated (sorry for this )in a comment on youtube, so probably the meter was ahead of it's time when it was developed / presented.
Check the specs for the first model of the 87V ... they are the same in terms of temperature and humidity ranges
I'm more convinced now that condensation on the board likely made the 189 go out of spec... the "Leads or Fuse error" should only ever occur with the dial in the amps measurement position. Plugging a lead into the amps jack while in the voltage measurement causes a "Leads error" without the "of Fuse," so some kind of current leak around the dial wipers probably occurred.
I doubt I will try and confirm this but if it's true, it's been a long time coming. To be clear, Gossen has never contacted me about this meter beyond the original posts.
If they have changed the design, it's too bad they didn't send me one. I would have repeated all my tests on it, including running RF susceptibility ($$$+++). They could have redeemed themselves, at least in my eyes.
One thing it shows is that one competent EE with a tiny channel but with honest, detailed reviews can actually get a company like Gossen to make a change. That's the only time, but I'll take it. :-DD
https://www.youtube.com/watch?v=Jf_9XWL3TD8&lc=z225ulhytqmfe5jro04t1aokgym3ty4x4pxmdgdysnmlbk0h00410.1566905126264437 (https://www.youtube.com/watch?v=Jf_9XWL3TD8&lc=z225ulhytqmfe5jro04t1aokgym3ty4x4pxmdgdysnmlbk0h00410.1566905126264437)
It's been over two years since I first looked at the 121GW prototype. UEI has had plenty of time to iron out any problems / shortcomings with the meter. There's a lot to cover so expect a series of videos.You are baaaaaack! Nice!
The 121GW Production DMM, Part 1, Initial checkout and tear down
They are hardly out of the box and already there are a few unexpected surprises.
These were purchased from the EEVBlog store about a week ago.The 121GW Production DMM, Part 1, Initial checkout and tear down
They are hardly out of the box and already there are a few unexpected surprises.
Where did you buy those from and when?
They still have the old firmware.
In my experience it is very difficult to update the firmware in units ready to ship, as the repackaging process can be intricate if there are sealed plastic enclosures, etc.These were purchased from the EEVBlog store about a week ago.The 121GW Production DMM, Part 1, Initial checkout and tear down
They are hardly out of the box and already there are a few unexpected surprises.
Where did you buy those from and when?
They still have the old firmware.
I think all the 121GW followers are aware that 1.57 is not the latest firmware but personally, I think the real question is why they are continuing to ship with the old firmware. I understand that it can be updated but it's a handheld meter, not a PC. If the changes truly do provide a significant improvement without introducing major problems, I would have expected it to be preloaded..
In my experience it is very difficult to update the firmware in units ready to ship, as the repackaging process can be intricate if there are sealed plastic enclosures, etc.
But I also agree the firmware shouldn't affect so much the functionality flaws seen on the video. The slow auto range is something really obnoxious and, if this is not hardwired on the chipset, it could potentially be improved by different firmware. The inaccurate measurements are more concerning, though.
Unless the firmware update addresses these two issues, I am from the school of thought that, if it is working, don't update.
If you followed my testing of the firmware, they were changing the filters on each new release.No, I haven't. Not having the meter my interest flows somewhere else.
The noise was getting really bad and the AC line rejection was suffering.There's no free lunch. :)
I assume the changes to the filters was made in attempt to reduce the settling time but it was making the meter worthless. I want a fast and accurate meter. If I have to choose between fast and inaccurate or slow and accurate, hands down I will take accurate every time.You can tell that Keysight thinks exactly like you when they designed the U1282A. I only wish they had put the resolution selection on a simple button press like the 87V. It is an excellent meter but &%$@! slow in 4-1/2 mode.
If you think reprogramming the firmware takes a lot of time, stay tuned for part 2 where I look at the hardware. The boards have some interesting rework which I dare say required a lot more time than it would take to install the latest firmware.Interesting, although hardware rework was probably done before packaging.
Thanks for the insights.If you followed my testing of the firmware, they were changing the filters on each new release.No, I haven't. Not having the meter my interest flows somewhere else.
The noise was getting really bad and the AC line rejection was suffering.There's no free lunch. :)
I assume the changes to the filters was made in attempt to reduce the settling time but it was making the meter worthless. I want a fast and accurate meter. If I have to choose between fast and inaccurate or slow and accurate, hands down I will take accurate every time.You can tell that Keysight thinks exactly like you when they designed the U1282A. I only wish they had put the resolution selection on a simple button press like the 87V. It is an excellent meter but &%$@! slow in 4-1/2 mode.
If you think reprogramming the firmware takes a lot of time, stay tuned for part 2 where I look at the hardware. The boards have some interesting rework which I dare say required a lot more time than it would take to install the latest firmware.Interesting, although hardware rework was probably done before packaging.
How accessible is it ? I thought it was behind the screwed-down fuse cover.
It is.
It takes less than 20 seconds to remove the holster, undo two screws (metal threaded insert), remove the battery cover and take out the SD card.
Yes, I timed it.
Hardly a chore for anyone who wants to do occasional data logging. And as I said, faster than dicking around with Bluetooth BLE and a ridiculously slow data rate.
If you are doing data logging all the time, I'd recommend buying a proper data logger with the convenient interface of your choice.
Do these changes only impact input protection?
Fuck me!
Looking at the changes on the Rev V.02 units, its obvious they have upped their game. So I just spent $600+ on old stock that I will pretty much bet is not going to survive to the same levels this new meter will. Look at the size of those transistors compared with the parts in mine.
I opened up the second meter just to make sure as it was a later SN. No luck, the two meters that were shipped are both the old design.
So I've burned down a fair bit of time, plus the cash. I am going to have to give it some thought on how to proceed.
...
This transistor clamping circuit on the additional PCB is obviously the circuit, which Dave had explained in his videos #1157 and 1158.
...
Another remark: the use of the 1N4007, as well as a TVS at that point both affect negatively the calibration of the 5M and 50M Ohm ranges by their leakage currents. Only without them, these ranges may work linearly.
PS Afaik Dave said "we are not going to spin a different pcb revision, we'll fix problems in software". Turned out either my memory is bad, or they changed their mind.
The latest is V.02.1910 which has the transistors integrated. Although they are not in the wild yet.
Fuck me!
Looking at the changes on the Rev V.02 units, its obvious they have upped their game. So I just spent $600+ on old stock that I will pretty much bet is not going to survive to the same levels this new meter will. Look at the size of those transistors compared with the parts in mine.
I opened up the second meter just to make sure as it was a later SN. No luck, the two meters that were shipped are both the old design.
So I've burned down a fair bit of time, plus the cash. I am going to have to give it some thought on how to proceed.
Hey Joe!
This transistor clamping circuit on the additional PCB is obviously the circuit, which Dave had explained in his videos #1157 and 1158.
I criticized though, that this does not work at all to protect the pin15 of MUX 4053, U9 for the Ohm circuit.
https://www.eevblog.com/forum/blog/eevblog-1157-transistor-zener-clamp-circuit/msg2043757/#msg2043757 (https://www.eevblog.com/forum/blog/eevblog-1157-transistor-zener-clamp-circuit/msg2043757/#msg2043757)
The circuit is able to protect symmetrical inputs, at +/- 6V clamp voltage, or +/- 20..25V, if special npn types are used.
This use case is asymmetric, as it has to be protected at -0.5V / + VDD ~ 4...16V.
I've never got a response from Dave, but obviously this not working circuit was implemented in certain HW versions of the 121GW.
It would be interesting, if in the most recent version, the BC diode of both transistors were properly used to protect the Ohm circuit, by using them as direct replacement of the original 1N4007.
Another remark: the use of the 1N4007, as well as a TVS at that point both affect negatively the calibration of the 5M and 50M Ohm ranges by their leakage currents. Only without them, these ranges may work linearly.
Frank
I just paid for two brand new meters and received the floor sweepings that are now apparently 2 PCB revisions old. I wasn't told anything about them being old stock when I made the purchase or I wouldn't have placed the order. I got fucked once. It won't happen again.
While I'd be interested in seeing every single version tested and compared, it doesn't really matter that much and is obviously impractical for a hobbyist to do so. Who knows how many more board revisions there will be in the future. In my mind, it's still the current version if that is what is being sold.
I just paid for two brand new meters and received the floor sweepings that are now apparently 2 PCB revisions old. I wasn't told anything about them being old stock when I made the purchase or I wouldn't have placed the order. I got fucked once. It won't happen again.
I am sorry to hear you got caught on the crossfire of revisions. I was looking forward for that series but, yes, I agree with you that your regular tests will not be greatly useful at this point in time. Perhaps get ahold of a modern schematics and try to implement in the new meter, à la UT61E improved protection exercise?
If only the revisions had an externally visible marker... Instead, cue the serial number merry-go-round. I wonder if UEI was avoiding an Osborne effect? If so, the cat is out of the hat. (but I confess I wasn't following the evolution that close anyways to know if this is old news).
Although any manufacturer states that "the products are subject to changes without prior notice", this reeks of a Uni-T UT61E stunt.
Frank,
About your comment, "I criticized though, that this does not work at all to protect the pin15 of MUX 4053, U9 for the Ohm circuit." I felt you (and possibly others) may have been a little confused.
I doubt I will make any changes to the hardware this time around. With the prototype, I had added two clamps in an attempt to protect the mux. If you watched the videos, may have noticed the TVS located across the supply of the mux (located on top of D7&D8). There was a second clamp that was located upstream from the resistor R82 but after the selector switch on node R_RLD. This first clamp acts like every other higher end meter I have looked at. It can withstand enough energy to overcome the PTCs thermal time constant. The PTC (PTC3) along with the surge resistor (R16) limit the current through the first stage clamp. The small resistor (R82) further limits the current. Again, the schematics are not up to date and I really didn't dig into how these meters are designed.
None of this is anything new as I went over it back in 2017 when I made the first series of videos for the prototype.
I suspect that the first stage clamp was enough to protect the mux but I never tested it. At the time my goal wasn't to optimize a production solution. That's UEI's job and that's assuming that they even wanted to try and improve it. Anyway, my point was that the meter may very well survive (my tests) without D7 & D8 present.
Hope that helps.
Hello Joe,
Frank,
About your comment, "I criticized though, that this does not work at all to protect the pin15 of MUX 4053, U9 for the Ohm circuit." I felt you (and possibly others) may have been a little confused.
I don't think at all, that I'm confused.
This critic is related to Daves videos #1157, especially 1158, not to any of your videos.
I also do not expect that you change the actual circuit, simply check what Dave has really implemented there.. as the latest revisions have some totally different transistors, and maybe a different circuit, all that already indicates, that this version you have on your table, did not work as intended.
I expect, that the DMM will fail, when you only run your usual (destructive) tests.
Frank
As a side note, I did receive a new message from Dave offering to replace the meters with the more current design. I have declined this offer as well for the reasons I mentioned earlier. If we run into a major problem that Dave knows was addressed in newer versions of the hardware, I just suggested he chime in.
Considering the confusion surrounding the prototype
But I also agree the firmware shouldn't affect so much the functionality flaws seen on the video. The slow auto range is something really obnoxious and, if this is not hardwired on the chipset, it could potentially be improved by different firmware.
I waited two years and you sent me old stock. That's on you.
Looks like she was drifting down. Don't include the settling time. :-DD Even more funny was seeing that slow Keysight lock right in and hold steady.
I waited two years and you sent me old stock. That's on you.
Fine. But like I said in my email if you had asked first I would have told you to hold off for a couple of weeks and I could have sent the new build that was on the way.
I do not usually pack and ship, so I had no idea you ordered these meters. If I had noticed I would have known what you had wanted them for and would have contacted you.
I can't help bad luck timing and lack of communication.
Looks like she was drifting down. Don't include the settling time. :-DD Even more funny was seeing that slow Keysight lock right in and hold steady.
Err, the Keysight displayed 9.7ohms at one point.
As for "drift" in the 1mOhm LSD, it's a switch, just my finger pressure can change by that amount. I checked, the Keysight "drifts" in a similar way, you just didn't happen to see it in the video.
Thanks for sharing the video; I can attest the Keysights drift some as well and I even commited that sin when I did my own video about the subject, although the U1273A was still using Keysight's evil smooth filter mode that crapped out everything on it (it became better after disabling it).Looks like she was drifting down. Don't include the settling time. :-DD Even more funny was seeing that slow Keysight lock right in and hold steady.
Err, the Keysight displayed 9.7ohms at one point.
As for "drift" in the 1mOhm LSD, it's a switch, just my finger pressure can change by that amount. I checked, the Keysight "drifts" in a similar way, you just didn't happen to see it in the video.
There was not supposed to be any confusion surrounding the prototype
Thanks for sharing the video; I can attest the Keysights drift some as well and I even commited that sin when I did my own video about the subject, although the U1273A was still using Keysight's evil smooth filter mode that crapped out everything on it (it became better after disabling it).Looks like she was drifting down. Don't include the settling time. :-DD Even more funny was seeing that slow Keysight lock right in and hold steady.
Err, the Keysight displayed 9.7ohms at one point.
As for "drift" in the 1mOhm LSD, it's a switch, just my finger pressure can change by that amount. I checked, the Keysight "drifts" in a similar way, you just didn't happen to see it in the video.
https://www.youtube.com/watch?v=EWZ0OSjYnvg (https://www.youtube.com/watch?v=EWZ0OSjYnvg)
Thanks for the video Joe, interesting as always, and thank you for continuing testing with your "new" 121gw's.
And just a note, don' know if you mentioned this but your 1nF reference cap which you measured to 992pF with the BK Precision, the BNC adapter you then used probably added 8-10pF in parallel, so reference cap the other meters saw was likely very close to exactly 1nF. Just to show how accurate some of them really were.
About the 121gw capacitance drifting, my (uneducated) guess is that it might have something to do with the SM6T22CA (D13 on the original 121 schematics), these devices seems to have a lot of nonlinear, voltage and probably temperature dependent capacitance behavior.
Perhaps a reason D13 now seems to been replaced with a traditional transistor clamp circuit in the latest hardware revision.
I was surprised how they coerce the reading to zero if the meter is powered on with no rel but if you are fast enough to rel it out, it will start to read negative values. Rel it after it have gone negative and it will again coerce to zero, no mater how far the meter continues to drift. I call this a bug.
So what! if it then perhaps initially will read something like negative 50pF or whatever with no probes attached, if that is what they are concerned about...
Guessing they felt the negative capacitance would cause a bit of confusion and decided to coerce it to zero. Lots of ways to skin this problem but what they have now isn't at all what I would have expected from a company who designs and produces DMMs.
Guessing they felt the negative capacitance would cause a bit of confusion and decided to coerce it to zero. Lots of ways to skin this problem but what they have now isn't at all what I would have expected from a company who designs and produces DMMs.
Do we know for sure that UEI "designs and produces DMMs"? For instance, do we know of other meters they make apart from the 121GW? I have the feeling their concerns lie elsewhere and the 121GW has been a bit of a departure from their normal product lines.
The drift is not acceptable ... even for a chinese multimeter .
Positive offset is "normal" if you look at a Fluke ~60pF , but it would be possible for 121GW's microcontroller to zero this at startup - of course when the drift issue is resolved .
I didn't said the drift is temperature related , in fact is highly unlikely because when you cycle through functions and back to cap , usually is reseted .No one suggested you did. I am only presenting you with the data I collected off the prototype. The prototype was one of the worst meters I had looked at for temperature drift. It will be interesting to see this old production hardware compares.
I've known UEI as a DMM manufacturer for quite some time. By the time the 121GW came about, they really had no meters on their lineup (all discontinued). They have now four meters, alongside a number of clamps and other measuring devices.Do we know for sure that UEI "designs and produces DMMs"? For instance, do we know of other meters they make apart from the 121GW? I have the feeling their concerns lie elsewhere and the 121GW has been a bit of a departure from their normal product lines.These would be good questions for Dave. He did post that video on the history of the 121 but I haven't watched it. You may find some of your answers there.
There was an early discussion about UEI getting out of the DMM business. With the data spread out, you may want to just try the advanced search and see what you can find.
(...) measuring a 2nF capacitor over an 8 hour period.Unless the tests are done by measuring a capacitor for 10s at every minute, which reflects a more practical scenario, what is the point of this? Capacitance testing on a DMM is useful only for a quick check, especially around its lower edge.
At some point, I will toss the 121 into that meat packing box and we can get some idea how it behaves over temperature.That is a much nicer test, especially since autumn is upon us! :-+
(...) measuring a 2nF capacitor over an 8 hour period.Unless the tests are done by measuring a capacitor for 10s at every minute, which reflects a more practical scenario, what is the point of this? Capacitance testing on a DMM is useful only for a quick check, especially around its lower edge.At some point, I will toss the 121 into that meat packing box and we can get some idea how it behaves over temperature.That is a much nicer test, especially since autumn is upon us! :-+
Going over my notes for the prototype to sort out what tests I plan to run. One of the problems I came across was with the VA mode. Roger, who ran the YT channel KainkaLabs, repeated my tests. He did a really nice job explaining the problem and how to work around it. I doubt I will go over this problem again, so if you're interested, I suggest you watch his video.
https://www.youtube.com/watch?v=FNsPr1OEq7c (https://www.youtube.com/watch?v=FNsPr1OEq7c)
Going over my notes for the prototype to sort out what tests I plan to run. One of the problems I came across was with the VA mode. Roger, who ran the YT channel KainkaLabs, repeated my tests. He did a really nice job explaining the problem and how to work around it. I doubt I will go over this problem again, so if you're interested, I suggest you watch his video.
That was a slick fix, Joe. :-+
About the 121gw capacitance drifting, my (uneducated) guess is that it might have something to do with the SM6T22CA (D13 on the original 121 schematics), these devices seems to have a lot of nonlinear, voltage and probably temperature dependent capacitance behavior.
Perhaps a reason D13 now seems to been replaced with a traditional transistor clamp circuit in the latest hardware revision.
So basically what you are saying , that drift is acceptable bacause we can zero it and still in specifications ? Sorry but for some people is not good enough ;D. What meter beside this do you use and is drifting ?
We understand that this is not 4 wire resistor mesurement , but the crappy design with low current is making things much worse that could be . Indeed , the voltage across the DUT resistor is so low that is comparable with every solder joint thermo voltage . You can verify this by heating the input jack , or every solder joint in the signal path . The value is drifting very much .
The biggest problem I saw so far with the old production hardware, with 1.57 or 2.02 firmware installed was that it failed to give any indication to the user that high voltages could be present in all conditions. IMO, this is really bad. A fellow member had pointed out that I had seen this with the prototype as well. I guess a few of you remember important things like this. This should NEVER happen.(Sorry, I am having trouble to catch up with all things...)
The attached is from EN 61010-2-033:2012. See note b). Seeing stuff like this and the Gossen with its latching relays getting through chips away at my trust in them.
The biggest problem I saw so far with the old production hardware, with 1.57 or 2.02 firmware installed was that it failed to give any indication to the user that high voltages could be present in all conditions. IMO, this is really bad. A fellow member had pointed out that I had seen this with the prototype as well. I guess a few of you remember important things like this. This should NEVER happen.(Sorry, I am having trouble to catch up with all things...)
The attached is from EN 61010-2-033:2012. See note b). Seeing stuff like this and the Gossen with its latching relays getting through chips away at my trust in them.
Do you mean that 121GW fails to present a OL on the display? Or only on certain ranges?
So, it is not really a problem with indicating an overvoltage condition but instead a problem in effectively finding the correct range to display. Given the read voltage on production #2 meter is so off, I imagine the circuitry/firmware completely failed to read the inputs.
Given the cost of every certification run is quite high, I have my doubts if every firmware revision goes through that process...
I watched the entire video, but I just mentioned #2 as it was the first that showed teh issue.So, it is not really a problem with indicating an overvoltage condition but instead a problem in effectively finding the correct range to display. Given the read voltage on production #2 meter is so off, I imagine the circuitry/firmware completely failed to read the inputs.
Given the cost of every certification run is quite high, I have my doubts if every firmware revision goes through that process...
Guessing you skipped a bit as I clearly show the problem is there even with 1.0 firmware installed. This problem dates back before the prototype 121GW I had looked at. I didn't make a big deal about it back then as it was, after all, a prototype. I should mention that someone recently wrote who had remembered seeing that early video.
Showing a low voltage in the presence of hazardous levels is exactly one of the examples used to describe an ambiguous indication. Again, I am not a safety expert and there may be a reason conditions like these get a pass. Personally, I think it dilutes the cert.My observation is simply my guess as to why there is no OL/hazardous indication: not a deliberate omission but I believe the meter is simply unaware of a high voltage on its inputs due to the autorange bug. In the end, the effect is the same regardless of the goof up.
I would expect companies that take these safety standards serious re-certify their product as changes made.Completely agree, although I suspect the rate of firmware releases does not allow for such intense testing - it costs real $$$ real fast. (although I didn't follow the FW evolution that close)
Hey Joe, dear dcac, CDaniel,
That clipping effect of Ohm mode is obviously removed latest with FW 2.02, but still present on the capacitance mode.
That explains the big errors you all see with small pF capacitors. This is evident as a threshold effect in capacitance value, i.e. the calibrated zero value plus the actual offset will always be subtracted from the real value. Capacitors smaller than this threshold will be displayed as 0.000pF, and bigger ones will show too small a value.
If I let my 121GW sit for a while in the 10nF range, it will possibly display some pF offset with open leads, and if I then zero the reading, I always get very precise values, even with pF capacitors (e.g. 39pF).
If that obvious (zero) drift is zeroed repeatedly between subsequent readings, then the measurement of the capacitors value is consistently precise, better than the specified 2.5%.
Long measurements on this zero drift make no real sense, I think.
Btw.: I can really check the accuracy by my DE-5000 LCR meter, which is specified down to 0.3% accuracy, depending on range and test frequency.
Interestingly, the actual manual (9/2019) still specifies this mode as:
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=48998.0;attach=875262;image)
I loaded FW 1.17, and indeed, the resolution then was 3 digits only, i.e. 10pF resolution in the lowest range.
That also means formally, that +5 digits, or 50 pf variation are allowed.
So do not expect too much of accuracy, because of this misleading specification, or because of the additional digit resolution.
The specification might be updated / improved to the 4 digit resolution, which seems to be quite reasonable, if that threshold problem can be solved.
Frank
******
It appears 1.05 is when they introduced the extra digit for the 50 ohm range.
If there is anything else you would like to see, feel free to ask.
******
It appears 1.05 is when they introduced the extra digit for the 50 ohm range.
Not exactly sure what you mean but it's been my understanding all FW released to the public, or since 1.02 anyway, have had the same resolution in all ohms ranges and 50 ohms range reading 50.000 ohms.
If there is anything else you would like to see, feel free to ask.
At the start of your last video where you had all the meters lined up for comparison I thought perhaps you may have been able conduct a similar test but set all the meters for Min/Max so as to gauge which meters can not only display a reading but capture it as well.
Yes that was the test, I frequently use this function and wondered what the result would be from a meter which was unable to settle or stabilise for the capture to occur.
The filter was changed in successive firmware updates for resistance just because we complained that is very sensitive to mains noise ( and still is ) , maybe you should test this , injecting some AC 50/60Hz and compare with other meters .
From my tests is at least 10 times more sensitive than a Fluke ...
The main entry point for noise are the long leads , so a bad designed meter appears to be good when tested with a short testing jig ...
Nothing complicated , for resistance inject AC across the test resistor , for every range .
For voltage maybe is enough just to inject an AC voltage and see if the 0 V DC fluctuates .
That tape eraser is a good indication that a meter is sensitive to noise , but you don't know for sure if the noise is entering through inputs or has a problem with the shielding inside , or other issue .
Yes that was the test, I frequently use this function and wondered what the result would be from a meter which was unable to settle or stabilise for the capture to occur.
I am not sure we are still talking about the same video as the problem I am showing in that last video appears not to be related to settling time but rather some problem with the autorange.
If this is really what you are asking about, for example, you would like to see the 121GW old hardware placed into its DC function with the Max selected. Apply the DC biased 60Hz AC waveform and see if the 121GW can detect the DC value?
We all wait that switch test :popcorn:
Meantime , my setup was simple , signal generator , constant voltage in parallel with the DUT resistor , I cranked up the voltage untill the value displayed fluctuates . I didn't choose the resistor to be in mid range or something ... of course you can standardise the setup as you wish .
The Fluke used were an 187 and an 867B graphical multimeter . So at 1Vpp 50Hz/60Hz 121GW fluctuates like mad but in a Fluke I could inject up to 10Vpp with minimal fluctuations , maybe 2-3 counts .
For Volts DC I didn't found to be a lack of filtering , the results were similar , of course I my test was mainly qualitative , not to measure exactly . You can go as deep as you like :D
I hope to get a part done each week, so in about 4 weeks I hope to show the results of the switch test.We all wait that switch test :popcorn:
Meantime , my setup was simple , signal generator , constant voltage in parallel with the DUT resistor , I cranked up the voltage untill the value displayed fluctuates . I didn't choose the resistor to be in mid range or something ... of course you can standardise the setup as you wish .
The Fluke used were an 187 and an 867B graphical multimeter . So at 1Vpp 50Hz/60Hz 121GW fluctuates like mad but in a Fluke I could inject up to 10Vpp with minimal fluctuations , maybe 2-3 counts .
For Volts DC I didn't found to be a lack of filtering , the results were similar , of course I my test was mainly qualitative , not to measure exactly . You can go as deep as you like :D
Very odd. This is pretty basic stuff, so lets try and clear up what you are asking. Anything I have that works down to 50Hz is DC coupled and will have a 50ohm source. These are meant to drive a 50ohm load. Let's ignore that and say you plan to go directly across the test resistor. I would expect placing that 50ohm source in parallel with a 50ohm test resistor for example will yield somewhere around 25ohms. Placing it in parallel with a 20Meg will yield something around 50ohms. You could add a large blocking cap (reason I asked about the coupling network) to strip the DC but you never mention it.
Let's just ignore all of that basic detail and assume your generator is DC coupled and is capable of driving 20Vp-p, with a 50ohm source. Now run that to a 50ohm thru terminator. Again, I would expect 25 ohms with the generator output set to 0V. At least we are in the center of the 50 ohm range. Assuming this setup is what you are doing, I would fully expect both meters to be effected as you turn up your generator to 20Vp-p. Maybe an offset.
With the 121GW, I suspect it will depend on the firmware that is installed. If you installed 2.02 for example, with your generator set to 2 volts (for your 1V test case), I wouldn't be surprise to see that meter still be all over the place. As Dave's speed test video shows, in that 50ohm range we can guess that they have continued to move the cutoff higher. From the tests I show, we could see the 1.00 firmware provided a much more stable display than 2.02 which also backs up what I am suggesting.
We know the meter is sensitive to the 60Hz from the tape eraser. I can only imagine what directly injecting a 1Vp-p signal will do to it. :-DD
I hope to get a part done each week, so in about 4 weeks I hope to show the results of the switch test.We all wait that switch test :popcorn:
Meantime , my setup was simple , signal generator , constant voltage in parallel with the DUT resistor , I cranked up the voltage untill the value displayed fluctuates . I didn't choose the resistor to be in mid range or something ... of course you can standardise the setup as you wish .
The Fluke used were an 187 and an 867B graphical multimeter . So at 1Vpp 50Hz/60Hz 121GW fluctuates like mad but in a Fluke I could inject up to 10Vpp with minimal fluctuations , maybe 2-3 counts .
For Volts DC I didn't found to be a lack of filtering , the results were similar , of course I my test was mainly qualitative , not to measure exactly . You can go as deep as you like :D
Very odd. This is pretty basic stuff, so lets try and clear up what you are asking. Anything I have that works down to 50Hz is DC coupled and will have a 50ohm source. These are meant to drive a 50ohm load. Let's ignore that and say you plan to go directly across the test resistor. I would expect placing that 50ohm source in parallel with a 50ohm test resistor for example will yield somewhere around 25ohms. Placing it in parallel with a 20Meg will yield something around 50ohms. You could add a large blocking cap (reason I asked about the coupling network) to strip the DC but you never mention it.
Let's just ignore all of that basic detail and assume your generator is DC coupled and is capable of driving 20Vp-p, with a 50ohm source. Now run that to a 50ohm thru terminator. Again, I would expect 25 ohms with the generator output set to 0V. At least we are in the center of the 50 ohm range. Assuming this setup is what you are doing, I would fully expect both meters to be effected as you turn up your generator to 20Vp-p. Maybe an offset.
With the 121GW, I suspect it will depend on the firmware that is installed. If you installed 2.02 for example, with your generator set to 2 volts (for your 1V test case), I wouldn't be surprise to see that meter still be all over the place. As Dave's speed test video shows, in that 50ohm range we can guess that they have continued to move the cutoff higher. From the tests I show, we could see the 1.00 firmware provided a much more stable display than 2.02 which also backs up what I am suggesting.
We know the meter is sensitive to the 60Hz from the tape eraser. I can only imagine what directly injecting a 1Vp-p signal will do to it. :-DD
This was not meant for the 50ohm range , low resistors , so you kill the generator , that's other story . Use 1K , 10K , 100K , 1M or any values you wish .
Some generators have internal output caps , you can add one , and a voltmeter to measure the actual AC voltage :D. Anyway this was not suposed to be an exact voltage test , just to find the root couse why is more sensitive to noise than other meters and ... the fluctuating reading is what you see and not something precise to corelate with the input voltage in milivolts ;D
Hi Joe
Just a wee note to thank you once again for the time,effort,expertise and MONEY you put into testing these meters.
Best regards
3db
Ditto what he said. Just so you know joe, I've read every post at least once, learned a LOT. Thank you for that too.Ditto here too. I'm too old to read every post but dang it, the testing's great! (I still miss the earlier fireworks fun) :-DD
Ditto what he said. Just so you know joe, I've read every post at least once, learned a LOT. Thank you for that too.Ditto here too. I'm too old to read every post but dang it, the testing's great! (I still miss the earlier fireworks fun) :-DD
Ditto what he said. Just so you know joe, I've read every post at least once, learned a LOT. Thank you for that too.Ditto here too. I'm too old to read every post but dang it, the testing's great! (I still miss the earlier fireworks fun) :-DD
I had written TPI requesting the alignment procedure for the 194II, explaining what had happened to the meter. They were able to supply me with everything I need.Nice! :clap: :-+
Points to TPI for customer service!!!!
My parts made it in early, so I ran some tests for Muttley Snickers and finished things up.
Most thermocouples output a negative voltage at temperatures below freezing. The sign-change can flush out issues with firmware or the CJC. ANENG just uses a fixed room temp value for CJC, in EEPROM.
I made a battery powered reference+Wheatstone bridge, to generate stable (thermocouple) mV signals of either polarity and use that to test hardware.
So could they really be doing no cold junction compensation at all? The Temp mode really appears to just read the DCmV and translate this to temperature using a LUT, though a LUT that gives much more resolution than the one for the NTC sensor.
The Brymen also reads -10C. The 121 is displaying -17.2C.
I wonder if the 121 is using this reading as their cold junction compensation. If so it's off by a mile.
The 121 manual specifies operation temperature 0 - 50C, so -10C is outside this range. But the NTC sensor conversion routine seems to be limited to -25C to 85C so at least I hope it is reasonable accurate between 0 - 50C.
I have upgraded my 1950's Olympus since looking at the last DMM. Button on my HP calculator.
Let's hope will remain unused and that the switch will be like brand new >:D
I have upgraded my 1950's Olympus since looking at the last DMM. Button on my HP calculator.
That's an easy one, it's an HP 20S. :popcorn:
you figured out how to make a picture take up a full page. Nice job!
One option would be to DL the picture, then reupload under your account. Or the simple option, don't link it at all. After all it was only one previous post.you figured out how to make a picture take up a full page. Nice job!
You don't get many options with "copy URL", "paste URL". You can only make them expandable if it's one of your own attachments.
One option would be to DL the picture, then reupload under your account. Or the simple option, don't link it at all. After all it was only one previous post.
Thanks. Want to tell a joke, finish this one:One option would be to DL the picture, then reupload under your account. Or the simple option, don't link it at all. After all it was only one previous post.
I fixed it.
PS: The joke was that I know perfectly well what calculator you use, I've seen it in your videos. It's easy to remember because it's the same one I use. Thanks for derailing that.
Two 121GWs walked into a bar and sat next to a Brymen and a Fluke....one of them says: can you believe that Keysight dude? It can't take a few rounds without falling apart!
So could they really be doing no cold junction compensation at all? The Temp mode really appears to just read the DCmV and translate this to temperature using a LUT, though a LUT that gives much more resolution than the one for the NTC sensor.
The cold junction compensation done on multimeters is to add the ambient temperature to the thermocoupler temperature and the ambient is often measured inside the multimeter chip, i.e. a long way from the correct location. This also means a multimeter may need one to two hours at a specific temperature before the internal sensor matches the actual cold junction.
There's a joke in there somewhere.....
There's a joke in there somewhere.....
I watched it all but I didn't hear any jokes. Anybody...?
:-DD Good job , so those 2 small SMD transistors for resistance protection are far worse than 2 x 1N4007 ... without further modifications . When you look at the schematic in series is just the thermistor ( 1K2) + 1K resistor + 100ohm SMD resistor the one that probably burned . The thermistor has a time lag to heat up and increase its resistance .
So the switch for how many cycles do you think will be good ?
Provided that Dave really has replaced these two 1N4007 by the reversed transistor diodes pair, (aka FLUKE protection), which he had promoted in two of his former videos, my prediction that this was useless, and the wrong approach, obviously has come true, as the Ohm range was far off after the overload experiments by Joe.
I'm no real friend of Joes further brutal destructive tests, as they seem to me being exaggerated and not conforming to the IEC et.al. test standards.
But anyhow, the 121GW really has big problems not to detect AC+DC signal overloads.
This has been discovered already when AC+DC current overloads were investigated in another thread.
So this is really a safety issue at high voltages, which should be solved by UEI.
Hopefully this can be done in SW, but I fear that this might be an intrinsic problem of the circuit, or of the chip set, precisely, of the way how AC signals were measured.
Frank
So should we make a guess that next hardware revision will have R82 (100 ohms) with a higher voltage rating, or perhaps higher resistance too?
And I seem to remember long long time ago Joe already predicted R82 will probably fail and it seems UEi/Dave did not get that message then, but perhaps now? - we can at least hope.
Something was dammaged ( leaky ) from the grill starter ... those 2 transistors were the perfect candidats ::) Maybe should be investigated more .
I think you did the thermal test before with the prototipe , was the same ( bad ) ?
I think you did the thermal test before with the prototipe , was the same ( bad ) ?
OK , I asked if the prototipe was the same in the tests you did back then , if you did . For voltage .
I am not sure what you are asking then.
About the grill starter test, when you tested the prototype not only did it survive but the test never seemed to reset the meter either, so that clamping design was better or more robust if you like. But here with the production meter it went into reset several times as if the voltage spike found a way in even to affect the MCU voltage rails.
I am not sure what you are asking then.I ask if the prototipe is worse , better , or the same for voltage temperature stability .
I doubt anyone can top the 121 for a joke.There's a joke in there somewhere.....I watched it all but I didn't hear any jokes. Anybody...?
Fungus, just keep in mind the CAT requires the operator survivability, not the meter. Joeqsmith's tests validate the electrical robustness. Although I suspect there is a correlation between the two.I doubt anyone can top the 121 for a joke.There's a joke in there somewhere.....I watched it all but I didn't hear any jokes. Anybody...?
I'm more glad then ever I didn't get one. Between the firmware problems, the shims to get the selector switch to make contact with the PCB, the SD card madness, and now this... it's a disaster.
It even seems like the CAT rating could be bogus.
Fungus, just keep in mind the CAT requires the operator survivability, not the meter. Joeqsmith's tests validate the electrical robustness. Although I suspect there is a correlation between the two.I doubt anyone can top the 121 for a joke.There's a joke in there somewhere.....I watched it all but I didn't hear any jokes. Anybody...?
I'm more glad then ever I didn't get one. Between the firmware problems, the shims to get the selector switch to make contact with the PCB, the SD card madness, and now this... it's a disaster.
It even seems like the CAT rating could be bogus.
I do the same in my videos but with much less voltage (~60Vac but on several seconds) just to show a bit of what to expect if the ranges are incorrectly selected.
That temperature drift from -10 to 60C is very concerning, and what the hell is causing it.Different parts inside the meter are changing at different rates when I ramp the box, even at this slow rate. With this meter, it causes a fair bit of error. I allow it to sit at the two extremes for a half hour to stabilize. There's not a lot of room in that box and there is a decent sized fan. At -10 we had 1.003mV, 20ish 0.997mV and 60C 0.928mV.
...
I just don't get it.
That temperature drift from -10 to 60C is very concerning, and what the hell is causing it.I allow it to sit at the two extremes for a half hour to stabilize. There's not a lot of room in that box and there is a decent sized fan. At -10 we had 1.003mV, 20ish 0.997mV and 60C 0.928mV.
...
I just don't get it.
It’s difficult to tell exactly as this part of your video is so time compressed, and is perhaps the overlayed chamber camera not really in sync, but:
121gw showing 0.899mV at -8.9c, control program (chamber temp) is shoving about 20c:
121gw showing 0.871mV at 20.9c, control program (chamber temp) is shoving about 43c:
121gw showing 0.997mV after 2h in 20.2c “room temperature”
so I get 0.899mV when chamber temp is shoving about 20c and then 0.997mV at 20c “room temperature”, why the big difference?
That temperature drift from -10 to 60C is very concerning, and what the hell is causing it.Different parts inside the meter are changing at different rates when I ramp the box, even at this slow rate. With this meter, it causes a fair bit of error. I allow it to sit at the two extremes for a half hour to stabilize. There's not a lot of room in that box and there is a decent sized fan. At -10 we had 1.003mV, 20ish 0.997mV and 60C 0.928mV.
...
I just don't get it.
But if you leave it in your car overnight in the dead of winter (much colder here than -10C) and bring it inside to use it, expect there to be a fair bit of error until it settles. Normally we would test something like this with a shock chamber but in my home lab, you have to settle for my cardboard box.
Probably the voltage reference is shitty ... pretty obviousProbably anything but, if it's the one (https://www.analog.com/media/en/technical-documentation/data-sheets/ADR3412_ADR3420_ADR3425_ADR3430_ADR3433_ADR3440_ADR3450.pdf) on the circuit diagram.
It’s difficult to tell exactly as this part of your video is so time compressed, and is perhaps the overlayed chamber camera not really in sync, but:
121gw showing 0.899mV at -8.9c, control program (chamber temp) is shoving about 20c:
121gw showing 0.871mV at 20.9c, control program (chamber temp) is shoving about 43c:
121gw showing 0.997mV after 2h in 20.2c “room temperature”
so I get 0.899mV when chamber temp is shoving about 20c and then 0.997mV at 20c “room temperature”, why the big difference?That temperature drift from -10 to 60C is very concerning, and what the hell is causing it.Different parts inside the meter are changing at different rates when I ramp the box, even at this slow rate. With this meter, it causes a fair bit of error. I allow it to sit at the two extremes for a half hour to stabilize. There's not a lot of room in that box and there is a decent sized fan. At -10 we had 1.003mV, 20ish 0.997mV and 60C 0.928mV.
...
I just don't get it.
But if you leave it in your car overnight in the dead of winter (much colder here than -10C) and bring it inside to use it, expect there to be a fair bit of error until it settles. Normally we would test something like this with a shock chamber but in my home lab, you have to settle for my cardboard box.
Yes it's VERY compressed. There's about 6 hours of data, maybe more. It takes several hours for that peltier setup to cool down to -10. You get to see the last half hour, the ramp and the hold at high temp. About 2 hours, compresses into a few seconds.
I have a sinking feeling that you feel that if you took a 1lb metal block, placed it in your freezer, left it overnight, take it out the next day and held it in your hand that it would be warm because it was no longer in the freezer. You don't seem to understand that there is a lag and it will take time for it to settle. We need to consider the thermal mass of the meter. The meter's case will provide some insulation.
I realize just because the 121gw internal sensor is showing a certain temperature doesn’t mean the rest of the meters internals is at that same temp (yet). But 0.870mV at 20.2C in the thermal chamber seems very far from 0.997mV at “room temperature” 20.2C.
Why? Do you feel that the meter is homogeneous in regards to temperature? There is going to be a slight temperature gradient when looking at the top of the meter near the LCD to the bottom near the leads. While the chamber is small and offers a fair amount of air flow, as we get closer to the Peltier's output, we are going to see a different temperature than whats going to their input. Again, one way to remove this effect is to allow everything to stabilize. You can't take a snapshot while things are changing and expect much more than to note that things are changing...I realize just because the 121gw internal sensor is showing a certain temperature doesn’t mean the rest of the meters internals is at that same temp (yet). But 0.870mV at 20.2C in the thermal chamber seems very far from 0.997mV at “room temperature” 20.2C.
As you can see I already mentioned there's a lag.
I still think it's strange that your chamber camera could catch 121gw showing 0.871mV at 20.9C on its internal sensor.
The thermistor measurement inside 121GW is not that good ... I see some self heating at room temperature so at low temperature could show way higher and then heating faster than the rest of the board .
It even seems like the CAT rating could be bogus.Fungus, just keep in mind the CAT requires the operator survivability, not the meter.
Oh, certainly so. I was just reinstating something that is an enabler of a very wide wiggle room between something that passes the independent testing and something that is seriously damaged.It even seems like the CAT rating could be bogus.Fungus, just keep in mind the CAT requires the operator survivability, not the meter.
True, but a loud bang and a jolt in your hand can easily make you fall off a ladder with surprise (or take a step back, put your foot in a bucket, fall over and grab a busbar on your way down...)
If this meter has sparks jumping around inside and tracks being vaporized at 2000V then it's not going to be pleasant to hold in your hand when 6000V@ 3000A hits it (ie. CAT III 600V). I don't know about you but I want a lack of surprises in my tools when I'm around dangerous things.But, but, but... Everyone LOVES surprises! :-DD
Why? Do you feel that the meter is homogeneous in regards to temperature? There is going to be a slight temperature gradient when looking at the top of the meter near the LCD to the bottom near the leads. While the chamber is small and offers a fair amount of air flow, as we get closer to the Peltier's output, we are going to see a different temperature than whats going to their input. Again, one way to remove this effect is to allow everything to stabilize. You can't take a snapshot while things are changing and expect much more than to note that things are changing...I realize just because the 121gw internal sensor is showing a certain temperature doesn’t mean the rest of the meters internals is at that same temp (yet). But 0.870mV at 20.2C in the thermal chamber seems very far from 0.997mV at “room temperature” 20.2C.
As you can see I already mentioned there's a lag.
I still think it's strange that your chamber camera could catch 121gw showing 0.871mV at 20.9C on its internal sensor.
The thermistor measurement inside 121GW is not that good ...I think the 121GW CJC circuit is powered (thermistor) from one Vreg (VDD U1) yet the MCU's A/D is off another (VDDP U2). So that drift would be a delta between two vanilla voltage regs. The precision vref is not used. The MCU's ADC input impedance is also 50k so that contributes. The MCU also has a calibrated on-ship temp sensor.
Looks like it takes about a half hour to warm up. Even after a 10min warmup I was seeing a bit of drift in the resistance measurements. Again, pretty typical. The odd ball is really just how stable that UNI-T UT181A is.
So it is good for volt scale , millivolt uses that transil diode D13 . If the leakage current is significant and variable with temperature a small variable voltage divider to ground is formed with the input thermistor + resistor 1K2+1K . Of course just a theory .
I can't recalibrate ... for some reason using a 10nF like in instructions result in 0.000nF readings in this range for any cap , so the only option is to reload the saved calibration . Maybe it's a bug , I tried many times even with different values , I don't think I did something wrong :-//
Also pay attention if you try to re-calibrate the capacitance ranges.
There is no entry for zero value calibration in the small table inside the chapter ZERO OFFSET CALIBRATION.
In the big colored table, though, there is a scrambled entry, 'R1 : ', which might indicate that the first calibration point with open leads sets the offset, and the 2nd one with the nominal reference capacitor sets the gain.
That might explain CDaniels problem, that 0.000 is displayed for a 10nF capacitor, after calibration.
Frank
Yes , is working that way , have you discovered by chance ? ;D Weird anyways ... the offset calibration is for zeroing the meter with nothing connected for stray capacitance or whatever
Now I have the meter without D13 and recalibrated for caps ... so far is not drifting .
I can't recalibrate ... for some reason using a 10nF like in instructions result in 0.000nF readings in this range for any cap , so the only option is to reload the saved calibration . Maybe it's a bug , I tried many times even with different values , I don't think I did something wrong :-//Also pay attention if you try to re-calibrate the capacitance ranges.
There is no entry for zero value calibration in the small table inside the chapter ZERO OFFSET CALIBRATION.
In the big colored table, though, there is a scrambled entry, 'R1 : ', which might indicate that the first calibration point with open leads sets the offset, and the 2nd one with the nominal reference capacitor sets the gain.
That might explain CDaniels problem, that 0.000 is displayed for a 10nF capacitor, after calibration.
Frank
I'm not sure if the capacitance calibration procedure ever been properly documented, I can't find it anyway, but here is what worked for me:
First make sure...
Dr. Frank, Dcac; joeqsmith, Sleppy et al:
I bought a 121GW that I received about a week ago. Today I noticed unusually poor capacitor readings (FW 2.02); now finding this capacitance discussion, I'm having buyer's remorse.
A 100 pf cap in my meter for several hours drifted only 1-2 pf, so drift isn't the issue. But at 67 pf, it's just way off.
Reading between the lines, perhaps, I get the impression that it will not be possible to get reasonable sub-100 pf readings. Since most of my work is 'portable', I do not want to drag a $10 meter along as a fix.
I'm not thrilled by the prospect of re-engineering the meter I bought to do work, nor am I qualified to do so.
What's your best suggestion?
Fabrice
_______________I can't recalibrate ... for some reason using a 10nF like in instructions result in 0.000nF readings in this range for any cap , so the only option is to reload the saved calibration . Maybe it's a bug , I tried many times even with different values , I don't think I did something wrong :-//Also pay attention if you try to re-calibrate the capacitance ranges.
There is no entry for zero value calibration in the small table inside the chapter ZERO OFFSET CALIBRATION.
In the big colored table, though, there is a scrambled entry, 'R1 : ', which might indicate that the first calibration point with open leads sets the offset, and the 2nd one with the nominal reference capacitor sets the gain.
That might explain CDaniels problem, that 0.000 is displayed for a 10nF capacitor, after calibration.
Frank
I'm not sure if the capacitance calibration procedure ever been properly documented, I can't find it anyway, but here is what worked for me:
First make sure...
Dr. Frank, Dcac; joeqsmith, Sleppy et al:
I bought a 121GW that I received about a week ago. Today I noticed unusually poor capacitor readings (FW 2.02); now finding this capacitance discussion, I'm having buyer's remorse.
A 100 pf cap in my meter for several hours drifted only 1-2 pf, so drift isn't the issue. But at 67 pf, it's just way off.
Reading between the lines, perhaps, I get the impression that it will not be possible to get reasonable sub-100 pf readings. Since most of my work is 'portable', I do not want to drag a $10 meter along as a fix.
I'm not thrilled by the prospect of re-engineering the meter I bought to do work, nor am I qualified to do so.
What's your best suggestion?
Fabrice
Keep in mind the test leads play a major part if you measuring capacitors and you want pF accuracy or resolution. If you watch Joe’s videos when he check meters against his reference box he’s using relatively short leads and is not touching them when reading the values in the pF range.
And here he’s using a ‘double’ BNC adapter to connect the capacitor, just for the reason of taking the test leads out of the equation.
This is really the only way to do it if you want to determine if you meter has a problem with small cap values. Also keep in mind even the BNC adapter adds 8-10pF to your reading.
That temperature drift from -10 to 60C is very concerning, and what the hell is causing it.I allow it to sit at the two extremes for a half hour to stabilize. There's not a lot of room in that box and there is a decent sized fan. At -10 we had 1.003mV, 20ish 0.997mV and 60C 0.928mV.
...
I just don't get it.
It’s difficult to tell exactly as this part of your video is so time compressed, and is perhaps the overlayed chamber camera not really in sync, but:
...
121gw showing 0.871mV at 20.9c, control program (chamber temp) is shoving about 43c:
....
so I get 0.899mV when chamber temp is shoving about 20c and then 0.997mV at 20c “room temperature”, why the big difference?
Dr. Frank, Dcac; joeqsmith, Sleppy et al:Yes, I understand the lead/stray capacitance issue, so I used no leads. I formed j-loops on the capacitor leads and plugged them directly into the meter. About 1" long each. That demonstrates a meter issue; as you say, probably calibration. I'd better tolerate a few pf of drift or ten seconds settling time than a constant 30-40% error on a 100 pf reading.
I bought a 121GW that I received about a week ago. Today I noticed unusually poor capacitor readings (FW 2.02); now finding this capacitance discussion, I'm having buyer's remorse.
A 100 pf cap in my meter for several hours drifted only 1-2 pf, so drift isn't the issue. But at 67 pf, it's just way off.
Reading between the lines, perhaps, I get the impression that it will not be possible to get reasonable sub-100 pf readings. Since most of my work is 'portable', I do not want to drag a $10 meter along as a fix.Keep in mind the test leads play a major part if you measuring capacitors and you want pF accuracy or resolution. If you watch Joe’s videos when he check meters against his reference box he’s using relatively short leads and is not touching them when reading the values in the pF range.
And here he’s using a ‘double’ BNC adapter to connect the capacitor, just for the reason of taking the test leads out of the equation.
This is really the only way to do it if you want to determine if you meter has a problem with small cap values. Also keep in mind even the BNC adapter adds 8-10pF to your reading.
Also, just note that I had shown adding that 1nF as a way get the meter above 0 so I could null it out. This part would remain in place, the meter was nulled, then you would add the part you want to measure.
It's too bad Dave hasn't released the older alignment procedure for the capacitance as it can be improved as I demonstrated.
If I understand the suggestion, other than for calibration, perhaps, there's no need for a 1.0000 nf reference capacitor: any stable cap that gets the meter to read somewhat above 0 even with test leads, would allow stable nulling if it remains connected in parallel with the test subject. If that's correct, then a dual banana plug and jack fixture holding the cap would work and be much easier to carry than another meter. Alternatively, a trimmer cap on the fixture to bring the reading to zero? Even so, I'm fixing equipment rather than fixing broken gear.
It's not obvious to me that is there consensus on the cal process. Am I wrong?? I do have a large assortment of "fully-aged" [old] caps, and could select some of various values, based on either/both an old Elenco LCR meter or a Fluke 83III, to effect re-calibration, even if not to the accuracy specs.
But this has given me an entirely new take on meter specs. What I presumed was simple documentation error (which I'd try to correct, along with fixing bad page links), now presents the impression of perhaps being a clever way to reduce the accuracy required for a chicken dinner. :clap:
I'm retired, and reflect on the high-end gear I saw discarded through corporate bankruptcy, take-overs, and downsizing to zero. So much equipment and so fully depreciated that they were not even trying to monetize it. I condemn my own lack of foresight. My only defense is that I didn't work the electronics, I worked the optics. :palm: (Is that irony?)
But I really appreciate your collective thoughts and experience, since your dedication to the subject shows it more central to your interests than mine. So, now what?
-Fabrice
....That is correct. Try it.
If I understand the suggestion, other than for calibration, perhaps, there's no need for a 1.0000 nf reference capacitor: any stable cap that gets the meter to read somewhat above 0 even with test leads, would allow stable nulling if it remains connected in parallel with the test subject.
If that's correct, then a dual banana plug and jack fixture holding the cap would work and be much easier to carry than another meter. Alternatively, a trimmer cap on the fixture to bring the reading to zero? Even so, I'm fixing equipment rather than fixing broken gear.In the latest manual, which I am sure you have read, it states for the 10nF range it has a resolution of 10pF and an accuracy of +/-2.5% +5counts. Of course latest firmware has a resolution of 1pF, not 10pF as the manual suggests. If it was +5 counts or 50pF in addition to the 2.5%, seems like it still would be the same, just with a higher resolution. That's a guess. The manual needs to be updated.
It's not obvious to me that is there consensus on the cal process. Am I wrong??
Enter calibration mode, select lowest cap range and connect a 1nF cap, meter will display a value probably somewhat less than 1nF, press Setup to perform offset cal, after count down meter will still display an offset value. Now change the 1nF to a 10nF cap, press Mem to perform gain cal, after count down meter will store both offset and gain calibration and should now display 10nF.
I have continued to work on the damaged 121GW (Production 2) and now have it working for the most part.
This meter was cycled from 5 deg C to 45 and back down to 5. Sweep1 is showing the entire data set. I was using a 1mV source. White is the chamber's temperature, Red is the 121GW's ambient temperature and Green is the reported voltage.
Sweep2 is looking at the voltage. You can see as the temperature is changing how the meter responds.
And the cause for this thermal anomaly ?
By the way , shitty switch indeed , I just had to open it , clean it and resettling those contacts , resistor/cap position developed an intermitent fault , no power or reseting if I touched it . And of course the meter wasn't used much at all .
I was amazed how fast the 121 seem to react to temperature changes. So here I have taken the green mV trace, flipped it vertically and overlayed on the two temperature traces where red being 121 internal temp and white the chamber temp.
....
Edit: correction! those two screenshots I've merged perhaps wasn't from the same sweep and therefor not in sync to begin with.
And the cause for this thermal anomaly ?
By the way , shitty switch indeed , I just had to open it , clean it and resettling those contacts , resistor/cap position developed an intermitent fault , no power or reseting if I touched it . And of course the meter wasn't used much at all .
I doubt I will dig into it but it could very well be one of the clamps.
Sorry to hear about the switch failing. What was your switch,
1) single dimple on all contacts
2) double dimple on outside contacts, single on inner
3) double dimple on all contacts
Platted? Shim orientation? Shimless with thin PCB? Shimless with thick PCB?
So many to choose from.. :-DD
Don't be sorry for me ;), at this point I don't care too much and I can sort this kind of problems by myself ... This is just for science , I doubt this meter will be ever 100% functional , maybe if somebody has too much time to rewrite the firmware . Even the cap in circuit measurement is not working right , very easily fooled by the components on the board when other meters have no trouble , but no point in complaining anymore .
Some time ago I put some picture for you , it is single dimple on all contacts with pre-installed shim . Now I put in reverse like in David's video , a little more tension on the contacts ;D I see some wear in the plastic where is touching the pcb inside the hole and fingers .
Maybe it has already been discussed before in this thread, but I am wondering why there are no cheap Fluke clones with good electrical robustness. Most of the techniques are in plain sight. Just copy the board with big clearances, large fuses and MOVs. It may cost a few more dollars for parts, but the margin for "professional" multimeters is much larger.
Fungus, "c" is only valid if you apply for their "listed" program (UL, TÜV, Intertek, etc.). The listing requires annual inspection to the manufacturing plant audits and process reviews. Most Chinese low cost meters do not go through that, but that does not solely explain lack of safety: several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings. It boils down to the manufacturer's reputation and seriousness.Maybe it has already been discussed before in this thread, but I am wondering why there are no cheap Fluke clones with good electrical robustness. Most of the techniques are in plain sight. Just copy the board with big clearances, large fuses and MOVs. It may cost a few more dollars for parts, but the margin for "professional" multimeters is much larger.
Because:
a) There's no need, sales of unsafe meters are doing just fine.
b) Certification costs money and you're not going to sell many meters without certification marks.
c) Once a meter is certified you're not allowed to change a single component supplier or any part of your production line without going through re-certification.
I suspect (c) is a real problem for Chinese meter makers.
[...] several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings. It boils down to the manufacturer's reputation and seriousness.
Do you work at one of these companies? If not, you can't possibly know that.[...] several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings. It boils down to the manufacturer's reputation and seriousness.
No- Sanwa, Hioki etc. will "design to" 61010 but never tested, no approvals, so it's another gamble.
Using gas-tubes for protection is a known no-no because of the follow-through current that exists with real mains-transients. OVC aren't just a high-voltage blip. Once a gas-tube is lit due to a transient, you have mains to deal with afterwards and in the 1/2 cycle arc flash happens, the part explodes.GDTs are useless, all of them fail exactly the same way and nobody manufactures them anymore. Oh, wait...
Now I'm thinking that perhaps, rather than run different brands, take the most notorious brand (Duracell) and just test those to discover the best mechanism for leakage FIRST, before testing all the brands?
And maybe get a bunch of small $2 farting novelty gadgets that takes two AA's that has a small standby current. I could get dozens of these on AliExpress and run various combinations.
Product recommendations?
[...] several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings. It boils down to the manufacturer's reputation and seriousness.
No- Sanwa, Hioki etc. will "design to" 61010 but never tested, no approvals, so it's another gamble. One spacings mistake and you learn why testing is done in the first place.
Using gas-tubes for protection is a known no-no because of the follow-through current that exists with real mains-transients. OVC aren't just a high-voltage blip. Once a gas-tube is lit due to a transient, you have mains to deal with afterwards and in the 1/2 cycle arc flash happens, the part explodes.
They seem to have no problem putting certification stamps on existing meters, whether outright fake or just shady. With plenty of review sites and videos, it wouldn't be hard to get a reputation for real robustness with a few large protection components.
Let's assume that companies who design DMMs are not stupid enough to place a MOV or GTD directly across the meter's inputs.
Fungus, "c" is only valid if you apply for their "listed" program (UL, TÜV, Intertek, etc.). The listing requires annual inspection to the manufacturing plant audits and process reviews. Most Chinese low cost meters do not go through that, but that does not solely explain lack of safety: several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings.Maybe it has already been discussed before in this thread, but I am wondering why there are no cheap Fluke clones with good electrical robustness. Most of the techniques are in plain sight. Just copy the board with big clearances, large fuses and MOVs. It may cost a few more dollars for parts, but the margin for "professional" multimeters is much larger.
Because:
a) There's no need, sales of unsafe meters are doing just fine.
b) Certification costs money and you're not going to sell many meters without certification marks.
c) Once a meter is certified you're not allowed to change a single component supplier or any part of your production line without going through re-certification.
I suspect (c) is a real problem for Chinese meter makers.
I had looked at I think a Tek-Power meter that had previsions to place some sort of clamp across the inputs but they were smart enough not to populate it.Let's assume that companies who design DMMs are not stupid enough to place a MOV or GTD directly across the meter's inputs.
That assumption is mostly correct, but in a very few cases it is not.
Which meters have you seen where they did this? Did any of these have some sort of safety certification?
Do you work at one of these companies? If not, you can't possibly know that.[...] several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings. It boils down to the manufacturer's reputation and seriousness.No- Sanwa, Hioki etc. will "design to" 61010 but never tested, no approvals, so it's another gamble.
As far as the protection circuits with GDT/spark gap, I see most are across the inputs in series with the usual 1.1kohm PTC, like in the 34401a, PM300, and with the extra 1kohm surge resistor for the Keysight handheld DMM'S.
The antique Beckman/Wavetek/Meterman/Amprobe Tech300/3000/HD110 family used 2kV GDT or spark gap directly across the multimeter's input. A bunch of Radio Shack models as well- these are all from pre-1010 era.
Only Fluke had a spark gap after the HV input resistor, back in the day when they used that instead of MOV's.
So an ionized gas tube would give different fault currents, some explosive due to follow-through current, and others much PTC smoke when on a DC bus (where GDT normally extinguishes at zero-cross on mains) where it's a long-term wiener roast due to the tube lighting up and keeping current flowing in the PTC.
Using gas-tubes for protection is a known no-no because of the follow-through current that exists with real mains-transients. OVC aren't just a high-voltage blip. Once a gas-tube is lit due to a transient, you have mains to deal with afterwards and in the 1/2 cycle arc flash happens, the part explodes.
You've probably done more testing and comparison across multiple brands than any manufacturer. Based on all that experience maybe can design your own meter with best protection features and start making it, to compete with EEVblog meter.
For high voltage behaviour even a tiny bit of resistance ( teraohms or more ) counts very much ... sparkgaps have very little as they are phisical gaps , MOV's and the other components obviously have much more . What do we see in the video is discharging in gases vs different dielectric materials . So for easy protection you would want a "leaky" material , obviously not desirable in long term as some degradation would occur . But for a fair test is very important that the equivalent input resistance to ground of the measuring IC is somewhat added after that 10Mohm resistor . I bet it counts very much .
I think what are Canadian friend doesn't realize is that some larger companies will have their own test facility. Suggesting HIOKI never tests their designs seems rather ignorant, similar to making a blanket statement that GDTs for protection is a known no-no. HIOKI has been designing equipment for AC mains testing for decades.Do you work at one of these companies? If not, you can't possibly know that.[...] several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings. It boils down to the manufacturer's reputation and seriousness.No- Sanwa, Hioki etc. will "design to" 61010 but never tested, no approvals, so it's another gamble.
Can we stop shilling multimeters from manufacturers such as Sanwa and Hioki, that have no 61010 safety approvals, only misleading statements such as "designed to" or "conforms to" or "safety rating" or "CE" which mean nothing.
Maybe for japanese market is enough and they don't care too much about the rest of the world ... :)
EN 61010-2-033 defines electrical safety for handheld multimeters.
SAFETY REQUIREMENTS FOR ELECTRICAL EQUIPMENT
FOR MEASUREMENT, CONTROL, AND LABORATORY USE –
The above is from Part 1: General requirements of 61010-1.
Part 2-033: Particular requirements for HAND-HELD MULTIMETERS
and other METERS, for domestic and professional use,
capable of measuring MAINS voltage
The test leads come up from time to time. These are covered in 61010-031.
It is THE document where CAT category ratings are defined as applied to multimeters for measuring mains voltages....
So no, they are not muppets. I trust them much more nowadays than Fluke run by bunch of greedy creeps that are coming from the same school of management as those scumbags that are running Boeing.. You know, taking some of the best and most respected companies in the world, firing all the engineers that made those companies great and milking the brand reputation as long they can, until they destroy it..
Let's not confuse "electrical robustness" with safety. I have yet to see a failure mode on these meters that will hurt the user.Good point.
Giving misleading readings is the only safety issue I've seen so far - how difficult would it be to design a meter with a universal HV warning? (AC, AC, DC+AC) Some indicator telling the user if it's safe or not even if the meter can't correctly display the reading.
I don't have anything to back your statement about "production stop due to the lack of certification". This is an exception that would probably be negotiated between the cert agency and the manufacturer.Fungus, "c" is only valid if you apply for their "listed" program (UL, TÜV, Intertek, etc.). The listing requires annual inspection to the manufacturing plant audits and process reviews. Most Chinese low cost meters do not go through that, but that does not solely explain lack of safety: several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings.Maybe it has already been discussed before in this thread, but I am wondering why there are no cheap Fluke clones with good electrical robustness. Most of the techniques are in plain sight. Just copy the board with big clearances, large fuses and MOVs. It may cost a few more dollars for parts, but the margin for "professional" multimeters is much larger.
Because:
a) There's no need, sales of unsafe meters are doing just fine.
b) Certification costs money and you're not going to sell many meters without certification marks.
c) Once a meter is certified you're not allowed to change a single component supplier or any part of your production line without going through re-certification.
I suspect (c) is a real problem for Chinese meter makers.
I have been involved with projects where "c" was required but wouldn't think this was required for a DMM. For example, say your JEDEC 4007 from company X is no longer offered, I doubt you would be required to stop production until you get your new diode certified. Have anything to back up this statement?
I don't have anything to back your statement about "production stop due to the lack of certification". This is an exception that would probably be negotiated between the cert agency and the manufacturer.Fungus, "c" is only valid if you apply for their "listed" program (UL, TÜV, Intertek, etc.). The listing requires annual inspection to the manufacturing plant audits and process reviews. Most Chinese low cost meters do not go through that, but that does not solely explain lack of safety: several japanese brands (Samwa, Hioki) have excellent quality and reputation and also do not have markings.Maybe it has already been discussed before in this thread, but I am wondering why there are no cheap Fluke clones with good electrical robustness. Most of the techniques are in plain sight. Just copy the board with big clearances, large fuses and MOVs. It may cost a few more dollars for parts, but the margin for "professional" multimeters is much larger.
Because:
a) There's no need, sales of unsafe meters are doing just fine.
b) Certification costs money and you're not going to sell many meters without certification marks.
c) Once a meter is certified you're not allowed to change a single component supplier or any part of your production line without going through re-certification.
I suspect (c) is a real problem for Chinese meter makers.
I have been involved with projects where "c" was required but wouldn't think this was required for a DMM. For example, say your JEDEC 4007 from company X is no longer offered, I doubt you would be required to stop production until you get your new diode certified. Have anything to back up this statement?
My experience with the marking process and audits is related to a few products (not DMMs) we were releasing in the past few years. We didn't fall for the siren songs from the cert agency (ies) as the markings didn't add value to our products, therefore I don't know how the exception would be dealt.
Happy new year, BTW!
I'm a little lost. Fungus made the statement in regards to meters which I don't believe they would be held to C. Are you asking under what circumstances we were or just merely pointing out that I did not provide any details?I guess the lines were crossed somehow. I was a bit confused and understood that you were asking me to provide documental proof about an assertive I haven't made. Nevermind. It is still early in the year... :P
It seems I saw it on 60 minutes. Doing a search, I came up with the attached from "Proposed Legislation Regarding Whistleblower Protection: H.R. 2579 ..., Volume 4":Quite interesting story. The snippet of document you sent has a striking resemblance with the whole 737MAX brouhaha: "Today consultants and private contractors not only build projects, they regulate them."
I'm a little lost. Fungus made the statement in regards to meters which I don't believe they would be held to C. Are you asking under what circumstances we were or just merely pointing out that I did not provide any details?I guess the lines were crossed somehow. I was a bit confused and understood that you were asking me to provide documental proof about an assertive I haven't made. Nevermind. It is still early in the year... :P
Quite interesting story. The snippet of document you sent has a striking resemblance with the whole 737MAX brouhaha: "Today consultants and private contractors not only build projects, they regulate them."
I was amazed how fast the 121 seem to react to temperature changes. So here I have taken the green mV trace, flipped it vertically and overlayed on the two temperature traces where red being 121 internal temp and white the chamber temp.
....
Edit: correction! those two screenshots I've merged perhaps wasn't from the same sweep and therefor not in sync to begin with.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=894150)
Left scale is voltage, right temperature. White is chamber temp, Red 121's ambient, Green reported voltage. Samples are roughly at 2Hz and lag is about 170 seconds. Of course, the time to settle is actually well over an hour in this case..
The latest spreadsheet is now available on GoogleDocs here:
https://docs.google.com/spreadsheets/d/1cXzYpIoyVm9QJUju4KXqM22CEQZP3_xwWvDyeVwxTy4/edit?usp=sharing (https://docs.google.com/spreadsheets/d/1cXzYpIoyVm9QJUju4KXqM22CEQZP3_xwWvDyeVwxTy4/edit?usp=sharing)
The latest spreadsheet is now available on GoogleDocs here:
https://docs.google.com/spreadsheets/d/1cXzYpIoyVm9QJUju4KXqM22CEQZP3_xwWvDyeVwxTy4/edit?usp=sharing (https://docs.google.com/spreadsheets/d/1cXzYpIoyVm9QJUju4KXqM22CEQZP3_xwWvDyeVwxTy4/edit?usp=sharing)
This spreadsheet seems out of date?
A bit late, but I can say, every Meterman PM55 or Amprobe PM55A I have has failed.I'm later still to the game, but I also had problems with the PM55A (and I have mentioned the problems with PM55A on the forum). I own two of them, one bought, one found in a trashcan (no, really!). They are utterly unreliable with constant "restarts" and who can have confidence in a meter that actually have an "reset" procedure printed on the back?
What happens:
- Auto mode freaks out and doesn't work (a short shows an unstable high resistance for example)
- Short detect mode shows shorted
- EF (power stick) mode works
- I can't remember what Low-Z volts does
- Hi-Z voltage works
- Diode mode acts like a short
- High ohms varies from not working to usually sounding the "shorted" beeper; IIRC high ohms will not give a stable reading
- Haven't tested current
What causes this?
The only similar thing I could find was a dying battery.
I purchased a new unit after my PM55A had failed, only to find a PM55 I gave to a friend also failed. I tested a PM55 I had and it too had failed. The replacement? Well, it tested good (testing 5V in auto mode, and shorting probes, that's it...); after a month when I went to use it to test a low voltage DC circuit again, it showed low battery ... and sure enough it failed too.
I'd like to fix them but have no idea where to start or what could have failed.
I'm later still to the game, but I also had problems with the PM55A (and I have mentioned the problems with PM55A on the forum). I own two of them, one bought, one found in a trashcan (no, really!). They are utterly unreliable with constant "restarts" and who can have confidence in a meter that actually have an "reset" procedure printed on the back?
But I may have a "fix". Instead of one CR2032, try two CR2016. It seems almost like the design had two batteries in mind. Of course, this "fix" more than halves the battery life and doubles the battery replacement cost, and 6 volts may still be too much for the design. With two 3 volts button cells, the constant restarts, confusion in auto mode and such disappeared and the meters seems stable. But still, I seldom use them anymore, since I don't really have confidence in them anyway.
Dave was posting hints about some new meter he was planning to sell but that seems to have cooled down.
Are you brave enough to send one to Joe ?Dave was posting hints about some new meter he was planning to sell but that seems to have cooled down.
The usual delays.
Just got an email that it will be going into UL testing very shortly and they want me to report any issue now (was supposed to have been through UL before, I guess it didn't, or they changed it for whatever reason).
I don't have a problem paying for it like everyone else and would rather wait until it has been vented and is available to the general public.Are you brave enough to send one to Joe ?Dave was posting hints about some new meter he was planning to sell but that seems to have cooled down.
The usual delays.
Just got an email that it will be going into UL testing very shortly and they want me to report any issue now (was supposed to have been through UL before, I guess it didn't, or they changed it for whatever reason).
Ok looking forward to that. Didn't know UniT had some new meters.
The efford&time you make to test these meters to the extreme is impressive.
And sometimes funny, when you killed that UT181A with just 1 click of the grill starter :-DD You so much wanted to like that meter, your reaction was priceless :-DD
In my experience it's pretty quiet in multimeterland especially on top models from the better brands. I suspect that most large brands are working on really intergrating logging/data processing, communications and maybe touchscreen etc (for instance, the fluke 289 has been 12 years on the market or so?, brymen doesnt have a real top model logging meter etc etc).
Dave's 121gw is I think one of the latest 'higher end' meters. And I think gossen replaced the series that you tested (the 300k count one), but with a similar capable model. Maybe/hopefully one without the multiple faults you've discovered ;)
Kiss Analog already did an interesting review on this meter (well, the previous 90DM600 model but its probably the same):
It appears the 90DM600(DT-9560) costs $86.18 and the 90DM610 (DT-9561) is $49.00.
I have not checked CEM to see what the differences were. I would not expect them to behave the same when tested.
No I don't really have the need for another 6k count meter as I already have several.
Also I live in europe, so there is at least a ~$30 charge for transport and taxes for the amazon meter, so it would come very close to the price of a bm235 (BM235 is here about ~€85).
Then the price difference becomes pretty low and the bm235 is of course a meter that has proven itself so for europeans that might be the better deal (or one of the higher brymens, they are priced pretty well here).
I think this meter is mainly a potential good deal for US based buyers on a tight budget, maybe young hobbyists that are starting with their electronics hobby (I can't see US shipping costs, but I presume it can come delivered free of charge with amazon prime or so).
I was mainly amaized at the US retail price for a UL listed/iec61010 compliant DMM (apart from whether these specs add something to the meter or not).
Normally for that price you sometimes don't even get ceramic sand filled fuses.
Is the DT-9561 UL listed? I was looking on the Amazon ad and in the manual they link and did not see where it was certified. The manual claims it meets UL... but there is no report number.You're right, that was an assumption of mine. I looked in the manual where they say it meets UL so I figured it was UL listed, but I haven't actually seen a report number or testing agency on the back of the 90DM610 (the pics on the amazon listing are generic pics)
Looking at the higher priced meter, I don't see a report number. Their pictures are not clear enough to see a UL mark.No indeed it's not in the manual, but in the kiss analog video an Intertek logo and file number can be seen:
The 121GW was certified by ETL as well. After seeing that meter pass their certification while not being able to perform a simple autorange, I have low confidence in their abilities.
Whether 90DM600 and 90DM610 are the same I don't know. Opening them up can only provide the answer ;).
I think specs and functionality from the manual are the same I believe for what I've seen.
The 121GW was certified by ETL as well. After seeing that meter pass their certification while not being able to perform a simple autorange, I have low confidence in their abilities.
With the UL 61010 not being an open norm (you have to pay dearly for it, and obviously I'm to cheap for that ;D), I don't really know what's in there, so I don't know if it's a matter of abilities or a matter of that the content and demands set out in the norm have any real competence or high set standards of quality in them. I also don't know if its standards concerning safety or robustness or whatever; I think its mostly (all?) safety stuff, so I imagine they want to see double isolation, isolation values of the casings and such. Maybe that's why a non/bad functioning meter can perfectly pass that norm.
All I know is that DMM reviewers usually point it out if the DMM has it or not when they review a DMM.
Browsing through the Intertek database I also saw that the popular Uni-T UT-61e is UL listed. Apparently that also meets UL 61010 standards. That immediately shows that the UL61010 standard at least isn't of much use for the gas grill repair man ;D :palm:
And in the Uni-Trend listings you can then also see that Uni-T makes products for amongst others AMPROBE, EXTECH, GRAINGER, GREENLEE, KLEIN TOOLS, MILWAUKEE, TENMA, Southwire, VOLTCRAFT, and BOSCH. Always interesting to see that (but not really unheard of of course)
The inside input protection of the Amazon Commercial 90DM600 as reviewed by Kiss Analog certainly looks similar with it's arrangement of PTC's and MOV's to the CEM DT9939 you've tested so indeed maybe it performs similar on that aspect.
Odd ETL would have the UL database. Are you sure that what you saw wasn't ETL testing the UT61E to the UL standards?
Odd ETL would have the UL database. Are you sure that what you saw wasn't ETL testing the UT61E to the UL standards?
You're right again. I'm looking in the Intertek database. I don't know how to look in the UL database. Didn't realize that's not the same thing, but makes sense.
So it's Intertek tested UL 61010 compliant.
And I think that also goes for the amazon commercial meters and CEM meters.
I don't know if Intertek can be trusted for safety certifications. I guess it all depends on what exactly is written in that safety certification.
If the things written in UL 61010 are not up to the standards/expectations you have when torture testing the meters to begin with, then it's not very useful to begin with. Have you a specific feature of the UL 61010 in your mind that Intertek does not check/check properly that makes you come to your opinion that ETL or Intertek can't be trusted?
I know you're not trying to prove if the meters are safe, but you specifically write about your opinion on the integrity of Intertek/ETL organisation compared to UL, and I wonder if that makes sense or not (nofi) where it say would be different if UL had tested them or whether the UL norm (UL61010) itself doesn't meet your expectations.
Again, I am not trying to prove if the meters are safe. You should take the time to read the FAQ.
I know you're not trying to prove if the meters are safe, but you specifically write about your opinion on the integrity of Intertek/ETL organisation compared to UL, and I wonder if that makes sense or not (nofi) where it say would be different if UL had tested them or whether the UL norm (UL61010) itself doesn't meet your expectations.
Again, I am not trying to prove if the meters are safe. You should take the time to read the FAQ.
Is non functioning autorange or being influenced by magnetic sources tested? (in any norm?). Maybe your expectations and assesmentcriteria of the concept of safety are way higher than is set out in these norms (they might form a very poor baseline to begin with; it's all a matter of how one's own expecations are).
Is non functioning autorange or being influenced by magnetic sources tested? (in any norm?).UL documents cost thousands of $$$ to read, I'm not sure anybody here has actually read the complete standard.
Whether 90DM600 and 90DM610 are the same I don't know. Opening them up can only provide the answer ;).
I think specs and functionality from the manual are the same I believe for what I've seen.
I haven't seen 90DM610, but have played with the 90DM600 (those used to sell about $30-$40 couple months ago....Amazon pricing is grazy)
https://www.eevblog.com/forum/testgear/amazon-commercial-90dm600-multimeter-hacks/ (https://www.eevblog.com/forum/testgear/amazon-commercial-90dm600-multimeter-hacks/)
It would seem these are pretty much identical meters except the rotary switch has one more position on 90DM610, while 90DM600 likely is otherwise exact same meter...
Some photos including photo of the Intertek logo/number can be found here:
https://www.eevblog.com/forum/testgear/amazon-do-multimeters-now/msg3040260/#msg3040260 (https://www.eevblog.com/forum/testgear/amazon-do-multimeters-now/msg3040260/#msg3040260)
I registred at UL and have now some acces to their database.
UT61e isn't listed, but it's predecessor, the UT-60A/B/C/D is.
Looking at the internals of the UT-60, that also looks like it doesn't have a whole lot of input protection & glass fuses:
https://oliversmith.io/technology/2009/12/27/inside-the-uni-t-ut60a-multimeter/
Maybe you can make more of it.
So I don't know if it's specifically an Intertek/ETL thing or that the UL 61010 isn't that high of a standard.
I believe the standard only refers to meter electricral breakdowns though. They want to know if the meter can create an arc flash and hurt you, they aren't concerned with the accuracy or reliability of the readings on the screen.
(please correct me if I'm wrong about that)
If a HAZARD could arise from an OPERATOR'S reliance on the value (for example, voltage) displayed by the equipment, the display shall give an unambiguous indication whenever the value is above the maximum positive value or below the minimum negative value of the range to which the equipment is set.
After the voltage of ..... has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
Seasoned electricians use cheap light bulbs to check for presence of lethal voltages, not fancy mulltimeters. Carry a battery pack with you to check the bulb is good before and after you test the circuit. KISS.
I believe the standard only refers to meter electricral breakdowns though. They want to know if the meter can create an arc flash and hurt you, they aren't concerned with the accuracy or reliability of the readings on the screen.
(please correct me if I'm wrong about that)
I would say you are wrong but again, I am not an expert. Consider these two sections:QuoteIf a HAZARD could arise from an OPERATOR'S reliance on the value (for example, voltage) displayed by the equipment, the display shall give an unambiguous indication whenever the value is above the maximum positive value or below the minimum negative value of the range to which the equipment is set.QuoteAfter the voltage of ..... has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
I believe the standard only refers to meter electricral breakdowns though. They want to know if the meter can create an arc flash and hurt you, they aren't concerned with the accuracy or reliability of the readings on the screen.
(please correct me if I'm wrong about that)
I would say you are wrong but again, I am not an expert. Consider these two sections:QuoteIf a HAZARD could arise from an OPERATOR'S reliance on the value (for example, voltage) displayed by the equipment, the display shall give an unambiguous indication whenever the value is above the maximum positive value or below the minimum negative value of the range to which the equipment is set.QuoteAfter the voltage of ..... has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
OK, I'll go with wrong.
I'm not sure how to interpret "the range to which the equipment is set" in the case of an autoranging meter though.
I also don't know how they can certify 100% that there's no software bugs in the autoranging process.
Whether 90DM600 and 90DM610 are the same I don't know. Opening them up can only provide the answer ;).
I think specs and functionality from the manual are the same I believe for what I've seen.
I haven't seen 90DM610, but have played with the 90DM600 (those used to sell about $30-$40 couple months ago....Amazon pricing is grazy)
https://www.eevblog.com/forum/testgear/amazon-commercial-90dm600-multimeter-hacks/ (https://www.eevblog.com/forum/testgear/amazon-commercial-90dm600-multimeter-hacks/)
It would seem these are pretty much identical meters except the rotary switch has one more position on 90DM610, while 90DM600 likely is otherwise exact same meter...
Some photos including photo of the Intertek logo/number can be found here:
https://www.eevblog.com/forum/testgear/amazon-do-multimeters-now/msg3040260/#msg3040260 (https://www.eevblog.com/forum/testgear/amazon-do-multimeters-now/msg3040260/#msg3040260)
I do own 90dm610 and can confirm that the markings on the back (referring to UL and Intertek standards) are identical to the ones on the back of 90dm600 as shown in sequoia's pictures.
Currently 90dm610 is $49 and 90dm600 is $86.18 (on Amazon USA). Yes, crazy prices (still have to figure Amazon's pricing strategy....)
It looks like a 50$ meter , it is funny how easily people compare them to a Fluke ;DI compare them all against one another. Blue, red, yellow, black... CE, TUV, CSA, UL... CATIII, IV, $free, $900, none of it matters. Few survive, some can be repaired, most are recycled.
My post was for that "review" youtube video , not about your tests ;DMost of the ones I see, they just take it out of the box and talk about how great they are. This is normally preceded by them telling you what an expert they are in some field. :-DD
People have been concerned with damaging their meters as long as there have been meters. Here's an article from the 50s. Note, they don't seem to care about safety.
People have been concerned with damaging their meters as long as there have been meters. Here's an article from the 50s. Note, they don't seem to care about safety.
like any new bench scope that will go boom if you touch the probe ground clip to a live wireWouldn't just the earth leakage breaker circuit/RCDO just trip?
like any new bench scope that will go boom if you touch the probe ground clip to a live wireWouldn't just the earth leakage breaker circuit/RCDO just trip?
We have no whole home ground fault breaker. I believe GFIs are required in bathrooms, kitchens and in close proximity to water.like any new bench scope that will go boom if you touch the probe ground clip to a live wireWouldn't just the earth leakage breaker circuit/RCDO just trip?
What's that.... 30mA or so? Can that cause a 'boom'?
I think they had in the late 60's.
Did they have those in the 1960s...? :popcorn:
If your house is fitted with such a device maybe ... but it is basically a transformer + relay , so not very fast for protecting active components if you work in something non insulated from mainsThe ground of your scope isn't an active component.
But it's very easy to fit/retrofit ... snip snip
Yes, but that wasn't the question.The answer to your question is that if you don't consider or upgrade your 1960's electricity net in the house, then you're living with 60 year old safety standards by now.
I wonder if this system would have detected the floating neutral.Well if you don't have any kind of RCD there is nothing detected for certain.
https://www.news.com.au/lifestyle/real-life/cause-of-12yearolds-tragic-electric-shock-revealed-after-the-child-was-left-brain-damaged/news-story/8d60948c20675e647236b2bc2e9e5a3d (https://www.news.com.au/lifestyle/real-life/cause-of-12yearolds-tragic-electric-shock-revealed-after-the-child-was-left-brain-damaged/news-story/8d60948c20675e647236b2bc2e9e5a3d)
(edit: this maybe goes all way too far offtopic, but I am genuine concerned about peoples safety, god forbid your own child ends up in a wheelchair braindamaged due to electric shock from a neglected electrical system or a system that misses basic safety from the beginning, and of course lots of tinkerers here sometimes with a lot of knowledge, and sometimes less: invest in an isolation transformer when trying to repair mains appliences, preferably one that you can regulate voltage, helps with fault tracing )
I'm sure many people are but it was never my intent to use this thread to discuss safety. The problem is that it confuses people, causing them to equate the tests I have ran with safety. This IMO places the uneducated at a higher risk, thinking products are safe when they may not be.
I'm sure many people are but it was never my intent to use this thread to discuss safety. The problem is that it confuses people, causing them to equate the tests I have ran with safety. This IMO places the uneducated at a higher risk, thinking products are safe when they may not be.
It's not just the product, either. Owning the best multimeter in the world doesn't make the overall process "safe".
Even on household mains you should be wearing gloves & ear/eye protection if the wires are hot.
Don't even think of going near high energy equipment without somebody else standing by with a telephone in their hand,
etc., etc.
(tie a rope around your waist so they can pull you out...)
As little as I know about safety, I know even less about US law. The DMM is a safety device. I assume most working in this environment have the training and PPE to keep them safe regardless. So it may not get tested in the courts. Still.....
I think I wrote about a friend who's a master electrician who never believed in PPE. He an another worker needed to make some measurements, suited up, went in with their long poles, hooked up to the bus and the meter exploded in my friends hands. He figures the PPE saved him that day and he became a firm believer after that.
Your brain should be your first safety device then the PPE then maybe the meter. If your an untrained idiot, there's not much that meter is going to do to save you.
Many years ago, I had heard about an electrician that had gone near the transformers for a factory and was vaporized. I am not too surprised after hearing from my friends about this other worker they knew. Having a rope or stick may not be very effective for an arcflash.
I think I wrote about a friend who's a master electrician who never believed in PPE. He an another worker needed to make some measurements, suited up, went in with their long poles, hooked up to the bus and the meter exploded in my friends hands. He figures the PPE saved him that day and he became a firm believer after that.
I think I wrote about a friend who's a master electrician who never believed in PPE. He an another worker needed to make some measurements, suited up, went in with their long poles, hooked up to the bus and the meter exploded in my friends hands. He figures the PPE saved him that day and he became a firm believer after that.
I've seen a couple of videos where the worker making measurements put the meter itself on the end of the long pole in capture mode and then made the measurements at pole's length before retrieving the meter to view the reading. That seems to me to be eminently sensible.
Just so. A rope or stick won't be much use when you're working with intermediate or high voltages.
The highest energy systems I have to deal with at work are low voltage customer end, so 400VAC 3ph and generally fused at no more than 1250A.
A wooden stick is more a humorous reminder for people (mainly but not always apprentices) to be careful or I'll beat them even more senseless than the shock they get.
I hope I didn’t derail the thread - I probably should’ve mentioned the Heathkit IM28 is a mains powered meter - with really no insulation of the input jack. My thoughts was mostly the safety aspects of following that procedure and that back in those days they even ‘suggested’ something like that. But if you knew what you were doing it probably was ok to follow it. I sure hope though people at least used a suitable insulated screwdriver as 'probe extension'.
The IM28 design is from 1968 but I think my dad bought the kit in 1977 or so - it was sold here in Sweden by a small import company. The transformer could be configured for 240V but it wasn’t delivered with any EU style mains plug. The cord is three wire but the plug that sits on it now is 2 prong - so the meter is floating so to speak. I think it could steer clear of any safety norms as it was sold as a kit and could be considered a 'home built’ device.
It is still probably working fine but hasn’t been used for the last 30 years or so.
I hope this tread stays open - the safety talk is probably unavoidable - now i.e. with the 121gw's high voltage ranging problem - that is a safety problem for sure. AFAIK it has not been addressed yet - it's been 7 months now?
I want to say the above was a 4KV and the one I was told where the workers body was vaporized was also at 4KV. In that case where the worker was killed, a second worker almost lost their life as well from that arcflash.
I'm not sure with the case involving the larger outside transformers but imagine those are upward of 10KV off the pole. I really don't know. I heard there were two others with him but I was unable to find any details on what happened. I knew people that worked at that plant who had told me about it.
On your 400V lines, do you send your workers out with lightbulbs as Fungus suggests? I just don't envision workers with their lightbulbs and free HF meters even in these environments.
This free, self-paced, online course describes the electrical dangers you may face in the workplace, the safety standards to protect you and the best practices involved with test tool safety.[/i]
Making a mistake while working on a high-energy electrical system can deliver a deadly blow to anyone who fails to take the right safety precautions. That’s why, at Fluke Corporation, your safety is our top priority.
This is for that ave agv ?? guy who was blabbing about safety all the while showing his hardware fuse installed. Too stupid to buy the right one. Worse, people watch this stuff and may actually believe the guy knows what he's doing.
This is for that ave agv ?? guy who was blabbing about safety all the while showing his hardware fuse installed. Too stupid to buy the right one. Worse, people watch this stuff and may actually believe the guy knows what he's doing.
Are you referring to AvE?
Joe, good video from Fluke. I'll watch it later.
Part II. Enjoy.
https://www.youtube.com/watch?v=1YYvr_qe4Tw (https://www.youtube.com/watch?v=1YYvr_qe4Tw)
I think I have a parts unit 77 (had a nasty battery leak), I think I may have stolen the fuses and the fusable resistor, but it has a case and other bits in case you want to get it going and test in a proper case.Someone else (perhaps you) had extended a similar offer in the YT comments. I appreciate the offer but I don't have any plans to revive it. It's not a rare meter and not something I would have a need for. If it were a 189, I would change my tune. Then again, if it were a 189, it would have survived.
Interesting. I haven't watched Part II yet. The rotary switch is trouble on these older meters IMHO. I had a 77 for years (which was my father's before) which wore out eventually and caused problems.
I think I have a parts unit 77 (had a nasty battery leak), I think I may have stolen the fuses and the fusable resistor, but it has a case and other bits in case you want to get it going and test in a proper case.Someone else (perhaps you) had extended a similar offer in the YT comments. I appreciate the offer but I don't have any plans to revive it. It's not a rare meter and not something I would have a need for. If it were a 189, I would change my tune. Then again, if it were a 189, it would have survived.
The battery had leaked at one point with this meter as well. It's odd to think of needing to split the case in order to gain access to the battery. You can really tell this meter is old from some of their early design choices.
They go on to develop the skills to later design and produce some very good products becoming a world leader to what we have today.
I think I have a parts unit 77 (had a nasty battery leak), I think I may have stolen the fuses and the fusable resistor, but it has a case and other bits in case you want to get it going and test in a proper case.Someone else (perhaps you) had extended a similar offer in the YT comments. I appreciate the offer but I don't have any plans to revive it. It's not a rare meter and not something I would have a need for. If it were a 189, I would change my tune. Then again, if it were a 189, it would have survived.
The battery had leaked at one point with this meter as well. It's odd to think of needing to split the case in order to gain access to the battery. You can really tell this meter is old from some of their early design choices.
They go on to develop the skills to later design and produce some very good products becoming a world leader to what we have today.
Honestly, looking at the 8060A, they almost went backwards with the 77, my guess is it was made to a price point. Though the 8060A doesnt have great input protection, its a great meter in most other respects, including having a battery/fuse access door... ::)
Honestly, looking at the 8060A, they almost went backwards with the 77, my guess is it was made to a price point.I think I have a parts unit 77 (had a nasty battery leak), I think I may have stolen the fuses and the fusable resistor, but it has a case and other bits in case you want to get it going and test in a proper case.Someone else (perhaps you) had extended a similar offer in the YT comments. I appreciate the offer but I don't have any plans to revive it. It's not a rare meter and not something I would have a need for. If it were a 189, I would change my tune. Then again, if it were a 189, it would have survived.
The battery had leaked at one point with this meter as well. It's odd to think of needing to split the case in order to gain access to the battery. You can really tell this meter is old from some of their early design choices.
They go on to develop the skills to later design and produce some very good products becoming a world leader to what we have today.
UEI 121GW, 50K, $300, virgin
I have changed my post above to reflect the cost you have quoted. I have also updated the spreadsheet.UEI 121GW, 50K, $300, virginFYI it's AU$300 or US$213
Joe,
First I'd like to thank you for all of your efforts in testing multimeters in a no BS manner :-+ :-+
Maybe you could include a Hioki DT4282 in your new round of tests. I would lend you mine if you are only doing non-destructive tests.
After two Part 1 and 2 not sure if that multimeter make any sense over e.g. BM867s.
I agree. The new meter seems to fit in a category that is more concerned about a general purpose use (lab/field) and does not care for dual display - something similar to choosing a BM857/9 versus a BM867/9. Besides, the 60000 counts can come in handy if you use 5V precision systems (the extra room above 5V can be of help).After two Part 1 and 2 not sure if that multimeter make any sense over e.g. BM867s.
It's smaller, it costs less, bigger display, it has AutoHold, and it has an EF tester.
Talk about responsive, Brymen is working on it. They suspect a problem with the new firmware. Apparently earlier versions don't have the problem. It sounds like they have a good handle on it. I plan to hold off on further testing until they have it sorted out.Funny how, in the past, that is what we would call it "beta testing": an almost finished product released to a few key customers to be trialed by fire. Nowadays this is almost the exception: alpha stage products released to the broad market where the issues are fed back to the devs through customer support. Oh well... Congratulations in reporting the bug.
I agree. The new meter seems to fit in a category that is more concerned about a general purpose use (lab/field) and does not care for dual display - something similar to choosing a BM857/9 versus a BM867/9. Besides, the 60000 counts can come in handy if you use 5V precision systems (the extra room above 5V can be of help).After two Part 1 and 2 not sure if that multimeter make any sense over e.g. BM867s.
It's smaller, it costs less, bigger display, it has AutoHold, and it has an EF tester.
Talk about responsive, Brymen is working on it. They suspect a problem with the new firmware. Apparently earlier versions don't have the problem. It sounds like they have a good handle on it. I plan to hold off on further testing until they have it sorted out.
Exchange rates vary, but today 133 EUR = 157 USD, so there is no difference.I agree. The new meter seems to fit in a category that is more concerned about a general purpose use (lab/field) and does not care for dual display - something similar to choosing a BM857/9 versus a BM867/9. Besides, the 60000 counts can come in handy if you use 5V precision systems (the extra room above 5V can be of help).After two Part 1 and 2 not sure if that multimeter make any sense over e.g. BM867s.
It's smaller, it costs less, bigger display, it has AutoHold, and it has an EF tester.
Really I would not be sure , 857s price is 133EUR also below 150 USD ... that would maybe sense if that would cost below 100 or so.
857s seems to be far more universal one.
Oh me ... I meant not BM657, but BM867S ... sorry for the mess.Exchange rates vary, but today 133 EUR = 157 USD, so there is no difference.I agree. The new meter seems to fit in a category that is more concerned about a general purpose use (lab/field) and does not care for dual display - something similar to choosing a BM857/9 versus a BM867/9. Besides, the 60000 counts can come in handy if you use 5V precision systems (the extra room above 5V can be of help).After two Part 1 and 2 not sure if that multimeter make any sense over e.g. BM867s.
It's smaller, it costs less, bigger display, it has AutoHold, and it has an EF tester.
Really I would not be sure , 857s price is 133EUR also below 150 USD ... that would maybe sense if that would cost below 100 or so.
857s seems to be far more universal one.
From the page I see at TME, the BM857 is 145 USD, which even still puts it in the same category of the other two (BM867 shows for me at 156 USD), making the difference too small to be considered another class.
The BM857 and the BM786 are quite similar with an edge for the BM786 if you don't need to do battery or trend measurements (the 500k counts mode)
Talk about responsive, Brymen is working on it. They suspect a problem with the new firmware. Apparently earlier versions don't have the problem. It sounds like they have a good handle on it. I plan to hold off on further testing until they have it sorted out.Funny how, in the past, that is what we would call it "beta testing": an almost finished product released to a few key customers to be trialed by fire. Nowadays this is almost the exception: alpha stage products released to the broad market where the issues are fed back to the devs through customer support. Oh well... Congratulations in reporting the bug.
Now, if others could get a clue and follow the same pattern of development cycle and customer support...
(BTW, your findings prompted me to resurrect an old project of mine for a HV low current Power Supply to test DMMs in more daring conditions - as well as exercise several HV capacitors).
Sounds like Brymen may have a fix. I'm surprised that they responded this quick, but it also sounded like they had a good idea where the problem was when I first wrote them.
While I offered to change the microcontroller, they have shipped a new meter. I should have an update in a few days for you.
Yes it is, minus EEVblog blue case (see reply #3770) An issue with AC+DC was found, so we get the benefit of Joe's testing.
Yes it is, minus EEVblog blue case (see reply #3770) An issue with AC+DC was found, so we get the benefit of Joe's testing.
I think testing is not finished yet, Joe may find new one >:D
Will you still run the problem meter through the rest of the tests?
Mostly just curious, but also thinking it might be a chance to see one fail early while the other manages to run most of the gauntlet, similar to what happened with the 87v tests. Been too long since I watched those now so I can't remember if there were actual differences in the board or not. Maybe not fair as one already is known to have a problem even if it is just firmware issue. Guess I was really just wanting to see the maximum number of meters fail (that are not mine) and I'm just being greedy.
Does the 789 suffer from the same problem or other problems?
Is the auto-range problem fixed on the Brymen 786? Does the 789 suffer from the same problem or other problems?
Is the auto-range problem fixed on the Brymen 786? Does the 789 suffer from the same problem or other problems?I'm not in any sort of rush and am giving Brymen time to sort it out. Until then, I have no plans to proceed with further testing. It sounds like they have told Dave it's all working now, so maybe we can get back into it soon.
They said they fixed the issue you raised and sent you a new meter. Not sure about the other stuff they hinted at.No doubt they are busy. I haven't heard anything from them in a while.
Expect maybe a few years and thousands of units in the field to get all the small issues ironed out, that's what the BM235 took.
Nope! My BM235 was perfect and I got an early model.
Dave, please convey to Brymen that Christmas is near!!!!
There is actually an issue (confirmed non-fixable though, Brymen call it a design limitation) in the BM235 that to my knowledge no one has encountered yet.
The issue that Joe found on the new meter most people would never notice, and I've seen that on other meters on the market. ...I noticed it withing a few minutes.
The issue that Joe found on the new meter most people would never notice, and I've seen that on other meters on the market. ...I noticed it withing a few minutes.
Because you just so happened by chance to have a test and level etc that showed up that particular issue. It could have just as easily been at some other signal level or frequency or waveshape you didn't test for.
As I said, the permutations are huge.
I would like to know what firmware changes and what bugs were fixed on the Brymen 786 apart from getting the nS function.
I'd be hesitating between Brymen 869 and 789/86.
I would use it for electronic repairs.
b) You need at least twenty meters.
I would like to know what firmware changes and what bugs were fixed on the Brymen 786 apart from getting the nS function.
The Brymen 7 series is newer and has more features, although it is less accurate.
I would like to know what firmware changes and what bugs were fixed on the Brymen 786 apart from getting the nS function.
The code base will almost certainly be identical on models, there would just be flags in the software to enable features like nS.QuoteThe Brymen 7 series is newer and has more features, although it is less accurate.
It's actually more accurate than the 869 on DC current.
1/
It looks like the 150USD gone sky-high to 188USD and with tax ... 184USD :-/O ( 158.82 € excl. VAT )
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
2/
Available from 10.01.2021, other models are also presented, like BM785 Available from 24.12.2020 for 125.21 € excl. VAT , BM789 starting 24.12.2020 for 150.42 € excl. VAT
Eee, really rationaly thinking will be to skip BM786 and go for less expensive and better BM789 , avaiable earlier
1/
It looks like the 150USD gone sky-high to 188USD and with tax ... 184USD :-/O ( 158.82 € excl. VAT )
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
1/
It looks like the 150USD gone sky-high to 188USD and with tax ... 184USD :-/O ( 158.82 € excl. VAT )
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
FYI I don't know where they got "paperwhite backlight" or that image from, but the backlight certainly doesn't look like that white or even.
1/
It looks like the 150USD gone sky-high to 188USD and with tax ... 184USD :-/O ( 158.82 € excl. VAT )
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
FYI I don't know where they got "paperwhite backlight" or that image from, but the backlight certainly doesn't look like that white or even.
paper-white is in Brymen pdf file.
1/
It looks like the 150USD gone sky-high to 188USD and with tax ... 184USD :-/O ( 158.82 € excl. VAT )
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
2/
Available from 10.01.2021, other models are also presented, like BM785 Available from 24.12.2020 for 125.21 € excl. VAT , BM789 starting 24.12.2020 for 150.42 € excl. VAT
Eee, really rationaly thinking will be to skip BM786 and go for less expensive and better BM789 , avaiable earlier
3/
Overal spec is not bad, but actually DC current accurancy is not that important, but AC indeed is quite important if specified for wide frequency range.
Although it measures a bit below the BM879 and Uni-T 181, the new improvements make me like the BM786 more than the BM869 for my work. Great job as always Joe. Thank you so much.
And ... yet more confirmation that Brymen is the new king of multimeter manufacturers.
Not checked manuall, they for sure described this, but I noticed that 60000 counts is not a full '60000'.
And ... yet more confirmation that Brymen is the new king of multimeter manufacturers.
Fluke should bring back 189 to make market position harder to Brymen. That old 189 is still better than this new Brymen (neglecting the price)
Not checked manuall, they for sure described this, but I noticed that 60000 counts is not a full '60000'.
AC is cut to two digits after dot, the same for resistance, same for current , that looks sometimes more like 6000 than 60000.
Actually e.g. 1mOhm resolution would be really very usefull.
But can you explain what are you talking about 6000 digits?
Interesting to see the Fluke 87V falling apart in tests where even a Uni-T keeps on going. :P
But can you explain what are you talking about 6000 digits?
All is about resolution e.g. for AC this will be 39.95 , but not 39.954V, e.g. for resistance it will be 28.04, but not 28.041 Ohms, e.g. for current 50.02 but not 50.025mA so really not different to a 6000 count multimeter.
I would not cry for AC volts , but actually 1mOhm resistance would be really very usefull.The same for AC current (10A socket).
No it is not like that. It is 60000 counts, BUT, for some reasons, on some measurements it didn't autorange to 60V AC range for 32V measurement, but stayed on 600V range, so it reads 032.00 V.
Fluke should bring back 189 to make market position harder to Brymen. That old 189 is still better than this new Brymen (neglecting the price)
S
But can you explain what are you talking about 6000 digits?
All is about resolution e.g. for AC this will be 39.95 , but not 39.954V, e.g. for resistance it will be 28.04, but not 28.041 Ohms, e.g. for current 50.02 but not 50.025mA so really not different to a 6000 count multimeter.
I would not cry for AC volts , but actually 1mOhm resistance would be really very usefull.The same for AC current (10A socket).
No it is not like that. It is 60000 counts, BUT, for some reasons, on some measurements it didn't autorange to 60V AC range for 32V measurement, but stayed on 600V range, so it reads 032.00 V.
S
But can you explain what are you talking about 6000 digits?
All is about resolution e.g. for AC this will be 39.95 , but not 39.954V, e.g. for resistance it will be 28.04, but not 28.041 Ohms, e.g. for current 50.02 but not 50.025mA so really not different to a 6000 count multimeter.
I would not cry for AC volts , but actually 1mOhm resistance would be really very usefull.The same for AC current (10A socket).
No it is not like that. It is 60000 counts, BUT, for some reasons, on some measurements it didn't autorange to 60V AC range for 32V measurement, but stayed on 600V range, so it reads 032.00 V.
MiroS, Sinisa, indeed this is a weird behaviour and to me a bug. Sure, while Joe had the waveform with plenty of DC offset, I imagine there was a chance the autorange could be confused in ranges, but not after wards, where a pure AC was applied.
Again, during the last test where the DC had been removed, the meter was set to VFD. The bargraph will be disabled, the filter will be active causing a bit of an voltage difference for the higher frequency content waveforms and yes, it only displays two places past the decimal point. We can see this on page 24.
Is it worth repeating this test with the VFD disabled? I could also just run two meter and remove the DSO, maybe slow it down a bit further to make it easier to track. We could also increase the number of waveforms. This test requires little effort to setup so if you feel it's worth it, let me know.
I am still not sure what the comment was about UNI-T not having a problem. I could toss the 87V into the mix as well if this is what you want to see. It just gets more difficult for me anyway, to follow what is going on with so many devices active at once.
Again, during the last test where the DC had been removed, the meter was set to VFD. The bargraph will be disabled, the filter will be active causing a bit of an voltage difference for the higher frequency content waveforms and yes, it only displays two places past the decimal point. We can see this on page 24.
Is it worth repeating this test with the VFD disabled? I could also just run two meter and remove the DSO, maybe slow it down a bit further to make it easier to track. We could also increase the number of waveforms. This test requires little effort to setup so if you feel it's worth it, let me know.
I am still not sure what the comment was about UNI-T not having a problem. I could toss the 87V into the mix as well if this is what you want to see. It just gets more difficult for me anyway, to follow what is going on with so many devices active at once.
Hi Joe,
If it is not big effort and you're willing to do it, sure, it would be nice.
It would be nice to see limits of this, and maybe with what waveforms it will happen. I doubt autoranging will have problem with standard waveforms...
Maybe see it through full range (6V, 60V, 600V) ... Definitely check whether it is VFD related.
...
There was a comment on YT that BM869s has a problem with 560kOhm resistance measurement if it is performed close to power cord. I would propose to add this to the list of tests if you will decide to make next tests with BM786.
... Definitely check whether it is VFD related.
...
But sure, if it can be fixed, it will be "betterer".
The BM786 Bar-graph does seems to have a strange behavior. Here it seems to be in 600.00V DC range but bar-graph would then correspond to 200 volts or so. Also note the DC is low but the BM786 seems to stay in the 600V DC as long as the overlayed AC is preset - it does not shift the range down to DC 5.0000V like the left Fluke 189.
To me a standard waveform would be something like IEC413.
There's nothing to fix. Again it's documented in the manual. Yes, it is all to do with the VFD mode. No big deal though to show it. Give me a while to repeat it.
Interestingly the BM786 LCD does seem to have a High Voltage warning symbol - but it's not mentioned in the manual and does never seem to be displayed either. Any particular reason for that? I think it's the same on BM869.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=1114054)
That warning symbol probably isn’t a requirement by any safety standard. And I’m not suggesting Brymen is less safe or anything like that - I just noticed the BM786 LCD has a symbol for it - so perhaps Brymen has planes to implement it in the future.
Again, during the last test where the DC had been removed, the meter was set to VFD. The bargraph will be disabled, the filter will be active causing a bit of an voltage difference for the higher frequency content waveforms and yes, it only displays two places past the decimal point. We can see this on page 24.
Is it worth repeating this test with the VFD disabled? I could also just run two meter and remove the DSO, maybe slow it down a bit further to make it easier to track. We could also increase the number of waveforms. This test requires little effort to setup so if you feel it's worth it, let me know.
I am still not sure what the comment was about UNI-T not having a problem. I could toss the 87V into the mix as well if this is what you want to see. It just gets more difficult for me anyway, to follow what is going on with so many devices active at once.
Hi Joe,
If it is not big effort and you're willing to do it, sure, it would be nice.
It would be nice to see limits of this, and maybe with what waveforms it will happen. I doubt autoranging will have problem with standard waveforms...
Maybe see it through full range (6V, 60V, 600V) ... Definitely check whether it is VFD related.
...
There was a comment on YT that BM869s has a problem with 560kOhm resistance measurement if it is performed close to power cord. I would propose to add this to the list of tests if you will decide to make next tests with BM786.
It can be exacerbated by holding the meter in your hands.
Again, during the last test where the DC had been removed, the meter was set to VFD. The bargraph will be disabled, the filter will be active causing a bit of an voltage difference for the higher frequency content waveforms and yes, it only displays two places past the decimal point. We can see this on page 24.
Is it worth repeating this test with the VFD disabled? I could also just run two meter and remove the DSO, maybe slow it down a bit further to make it easier to track. We could also increase the number of waveforms. This test requires little effort to setup so if you feel it's worth it, let me know.
I am still not sure what the comment was about UNI-T not having a problem. I could toss the 87V into the mix as well if this is what you want to see. It just gets more difficult for me anyway, to follow what is going on with so many devices active at once.
Hi Joe,
If it is not big effort and you're willing to do it, sure, it would be nice.
It would be nice to see limits of this, and maybe with what waveforms it will happen. I doubt autoranging will have problem with standard waveforms...
Maybe see it through full range (6V, 60V, 600V) ... Definitely check whether it is VFD related.
...
There was a comment on YT that BM869s has a problem with 560kOhm resistance measurement if it is performed close to power cord. I would propose to add this to the list of tests if you will decide to make next tests with BM786.
I can confirm that this is a thing. It starts at around 520k and persists up to 660k or so. It can be exacerbated by holding the meter in your hands.
I ran cables from a resistance decade to my meter, with a few cm being parallel to my PC power lead.
I was unable to duplicate the effect with my 87V, 289, or UT139C.
I'm guessing it's some kind of low hysteresis between the autorange selection between 600k and 6M, as it basically starts flipping between them at a rate of two or three Hz.
The video linked by MiroS shows the same issue on the 869s
The video linked by MiroS shows the same issue on the 869s
Actually this video is mentioning three problems for 869s, I think it is worth of checking is new multimeter is affected by them.
From Dave message - resisatnce sims to work, but who knows which firmware is in Dave multimeter, that may be old one, Joe could be one of first external testers for corrected/imporved firmware.
I think Brymen may be still not aware of issues, I do not think that anyone reported this to them for 869s.
Actually this video is mentioning three problems for 869s, I think it is worth of checking is new multimeter is affected by them.
Actually this video is mentioning three problems for 869s, I think it is worth of checking is new multimeter is affected by them.
It would be nice to try the new meter. I agree. Has it been tested with Fluke cables?
Actually this video is mentioning three problems for 869s, I think it is worth of checking is new multimeter is affected by them.
It would be nice to try the new meter. I agree. Has it been tested with Fluke cables?
1. First problem is one with resistor. It has to do with instrument having high impedance and on the edge of autoranging ... It does seem a bit nervous, but any meter can be destabilised this way if you try hard enough.
1. First problem is one with resistor. It has to do with instrument having high impedance and on the edge of autoranging ... It does seem a bit nervous, but any meter can be destabilised this way if you try hard enough.
Yep. I bet it will disappear if you switch to manual ranging.
Also Dave's test with BM786 is invalid .. Of course that 60000 count meter won't have problem with 560 kOhm. It might have problem with 650 kOhm, because that is where it will have switchover and similarily high impedance.....
The video linked by MiroS shows the same issue on the 869s
Actually this video is mentioning three problems for 869s, I think it is worth of checking is new multimeter is affected by them.
From Dave message - resisatnce sims to work, but who knows which firmware is in Dave multimeter, that may be old one, Joe could be one of first external testers for corrected/imporved firmware.
I think Brymen may be still not aware of issues, I do not think that anyone reported this to them for 869s.
1. First problem is one with resistor. It has to do with instrument having high impedance and on the edge of autoranging ... It does seem a bit nervous, but any meter can be destabilised this way if you try hard enough.
Yep. I bet it will disappear if you switch to manual ranging.
Of course it will, it is autoranging problem. You have value right at the edge of range, very high impedance on input and you're injecting maybe a volt of interference. That combined with fast frontend, makes a jittery autoranging. We are all annoyed when things are not perfect, but it is not a real problem.
The video linked by MiroS shows the same issue on the 869s
Actually this video is mentioning three problems for 869s, I think it is worth of checking is new multimeter is affected by them.
From Dave message - resisatnce sims to work, but who knows which firmware is in Dave multimeter, that may be old one, Joe could be one of first external testers for corrected/imporved firmware.
I think Brymen may be still not aware of issues, I do not think that anyone reported this to them for 869s.
1. First problem is one with resistor. It has to do with instrument having high impedance and on the edge of autoranging ... It does seem a bit nervous, but any meter can be destabilised this way if you try hard enough. This is something I would like if Brymen could make better, but would not change the meter because of it.
2. Second problem I don't really understand what is he doing..
3. 3rd problem is not a problem at all and has nothing to to with VFD, Crest mode has less resolution, in order to be fast enough. It's in a manual.
So to an inexperienced user the BM896 might (possible) seem to be broken when it is in fact just different - or in this case less sensitive on the frequency display - than another multimeter.
So to an inexperienced user the BM896 might (possible) seem to be broken when it is in fact just different - or in this case less sensitive on the frequency display - than another multimeter.
No , no ... look starting at 4:04 - 117AC on input ...
The same BUG with 235V AC 50Hz, no question for me , that is a real bug.
So NOT a bug. Bug is unexpected behaviour. This is not unexpected behaviour. It is clearly documented in specifications. Fact is BM869S has frequency measurement that is not very sensitive, and you need to be in right range for it to work. It probably makes measurements stable and resilient to noise.
So NOT a bug. Bug is unexpected behaviour. This is not unexpected behaviour. It is clearly documented in specifications. Fact is BM869S has frequency measurement that is not very sensitive, and you need to be in right range for it to work. It probably makes measurements stable and resilient to noise.
Right , I am idiot -> '1000.0V = 280V', but really ... |O
The video linked by MiroS shows the same issue on the 869sActually this video is mentioning three problems for 869s, I think it is worth of checking is new multimeter is affected by them.
From Dave message - resisatnce sims to work, but who knows which firmware is in Dave multimeter, that may be old one, Joe could be one of first external testers for corrected/imporved firmware.
I think Brymen may be still not aware of issues, I do not think that anyone reported this to them for 869s.
So NOT a bug. Bug is unexpected behaviour. This is not unexpected behaviour. It is clearly documented in specifications. Fact is BM869S has frequency measurement that is not very sensitive, and you need to be in right range for it to work. It probably makes measurements stable and resilient to noise.
Right , I am idiot -> '1000.0V = 280V', but really ... |O
I don't know you so I will have to trust your word on that.
I will repeat: I took my BM869S, connected it to 237.00 V 50Hz mains, it autoranged to 500V range and shown 50Hz correctly. Then I manually ranged to 1000V range, it shown 0237.0 V and 0 Hz. It didn't measure frequency , because according to datasheet, you need 500 V RMS minimum in 1kV range for frequency measurement to work. Is it inconvenient that it doesn't measure it in that range ? It probably might have been made to work, but who cares. Just leave it in autorange, it will autorange to 500V range and measure frequency nicely
I don't know you so I will have to trust your word on that.
Please post about he BM869 issue here so we don't pollute this thread.
https://www.eevblog.com/forum/testgear/brymen-bm869-resistance-quirk/ (https://www.eevblog.com/forum/testgear/brymen-bm869-resistance-quirk/)
But higher frequencies will likely require higher voltages.True.
How sensitive is the BM869s in its upper resistance range compared with other meters?
How sensitive is the BM869s in its upper resistance range compared with other meters?
Old Fluke 25/27 can measure 2kOhms with 1V AC, 1MOhm with up to 2V AC noise.
That noise is visible as an oscillating bar graph.
If you have some pots, you could try to find the thresholds, then measure the pots values. Then set the pot to the mid point and try to see what voltage level upsets it.
The newer Brymen BM869s with the latest firmware has thresholds of 540K and 470K ohms. Setting the decade box to 505K, the meter is unstable at as low as 27mVRMS. Test current was around 0.85uA.
If you have some pots, you could try to find the thresholds, then measure the pots values. Then set the pot to the mid point and try to see what voltage level upsets it.
I took this data from Fluke manual, not by testing, no idea why Fluke published this for 2k and 1M, and no idea if this could be a trend that lower resistance is more sensitive (1V) than higher resistance (2V)
Quote from: joeqsmith on November 19, 2020, 02:02:50 am
I have repeated the DCV test to see if I could replicate the problem with the bargraph. It doesn't look like it locks up but rather that they calculate it differently than the readout. It's really strange but easy to reproduce. I have asked Brymen if they can fill us in on what it's doing.
The digital reading and analog bargraph of BM780 DCV function come from different algorithm designs. Analog bargraph algorithm uses faster converter to get the peak averaging RMS (not True RMS) of the input signal. That is the reason why bargraph display speed is more faster than digital reading update speed. That is also the reason why bargraph algorithm can be with the mechanism to judge if the input DCV is with additional high ACV and if meter should auto switch to higher measuring range in case of being with high ACV. Nevertheless, its peak averaging RMS algorithm design is with a nature. While the DCV level is less than ACV peak, the bargraph will display ACV peak averaging RMS only. The bargraph will start to reflect DCV component only in case DCV level is higher than ACV peak. That is the reason why the bargraph appeared to lockup against your tests.[/i]
Someone had posted this link, asking me if the new meter was going to be available January.
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
To be clear, I don't have any inside knowledge as to when the meter is going to be available, what the cost will be or who will be distributing it. Ultimately it's up to Brymen.
Someone had posted this link, asking me if the new meter was going to be available January.
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
To be clear, I don't have any inside knowledge as to when the meter is going to be available, what the cost will be or who will be distributing it. Ultimately it's up to Brymen.
The BM786 is exclusive to the EEVblog, it will not be sold under any other brand or dealer.
Welectron and Spark Labs/Simon's Electronics are the only dealers who will carry it.
You'll have to buy the BM789 or the lower model if you want the Brymen brand.
Someone had posted this link, asking me if the new meter was going to be available January.
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
To be clear, I don't have any inside knowledge as to when the meter is going to be available, what the cost will be or who will be distributing it. Ultimately it's up to Brymen.
The BM786 is exclusive to the EEVblog, it will not be sold under any other brand or dealer.
Welectron and Spark Labs/Simon's Electronics are the only dealers who will carry it.
You'll have to buy the BM789 or the lower model if you want the Brymen brand.
What about price and release date? Anything solid yet?
The BM786 is exclusive to the EEVblog, it will not be sold under any other brand or dealer.
Welectron and Spark Labs/Simon's Electronics are the only dealers who will carry it.
You'll have to buy the BM789 or the lower model if you want the Brymen brand.
Someone had posted this link, asking me if the new meter was going to be available January.
https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1 (https://www.welectron.com/Brymen-BM786-Multimeter-EEVBlog-Edition_1)
To be clear, I don't have any inside knowledge as to when the meter is going to be available, what the cost will be or who will be distributing it. Ultimately it's up to Brymen.
The BM786 is exclusive to the EEVblog, it will not be sold under any other brand or dealer.
Welectron and Spark Labs/Simon's Electronics are the only dealers who will carry it.
You'll have to buy the BM789 or the lower model if you want the Brymen brand.
What about price and release date? Anything solid yet?
No release date yet, they are still working on it.
Like I said, I can sell it significantly under US$150. Reseller prices and amazon prices may vary.
For those who want it cheap sign up for my newsletter on the website and you'll get notified of a discount when it goes on sale.
The BM786 is exclusive to the EEVblog, it will not be sold under any other brand or dealer.
Welectron and Spark Labs/Simon's Electronics are the only dealers who will carry it.
You'll have to buy the BM789 or the lower model if you want the Brymen brand.
I'm curious as to why neither you nor Brymen have a US distributor?
or maybe it's because he's a one man shop with 2 sons looking up to him? If he extends trust to a US rep to carry a $25K stock level on all his merch and a cash float of $10K to manage flow, one false move and someone may miss-out on college..The BM786 is exclusive to the EEVblog, it will not be sold under any other brand or dealer.
Welectron and Spark Labs/Simon's Electronics are the only dealers who will carry it.
You'll have to buy the BM789 or the lower model if you want the Brymen brand.
I'm curious as to why neither you nor Brymen have a US distributor?
Greenlee and AMPROBE have rebranded some of their products. Maybe there are others.
The BM786 is exclusive to the EEVblog, it will not be sold under any other brand or dealer.I'm curious as to why neither you nor Brymen have a US distributor?
Welectron and Spark Labs/Simon's Electronics are the only dealers who will carry it.
You'll have to buy the BM789 or the lower model if you want the Brymen brand.
Are you waiting on a final cost from Brymen? Just curious as when I asked them about pricing, they also gave me a vague sort of answer. A range based on other products.
Like I said, I can sell it significantly under US$150.
Of course that's fine.Are you waiting on a final cost from Brymen? Just curious as when I asked them about pricing, they also gave me a vague sort of answer. A range based on other products.
They gave you a vuage answer because they don't set retail prices, and various dealers would likely have different FOB cost deals and different margins.
I've just been lazy and haven't worked out a final retail cost yet, is that ok?
Makes me wonder how much Fluke makes on every meter.
Does any brymen meter beep in diode mode like flukeApparently this person believes Fluke only makes one product or that all Fluke products behave the same.
It's the middle of summer and the office is fairly warm. Even with all the insulation, the small Peltiers are having a difficult time reaching -5C.If you were making money out of these tests, a chest freezer would be your christmas gift! :-+
I doubt using better resistors and a good relay would make any difference for the settling time. Originally, I would just short them but it seems Dave had posted some data with a 10 ohm and I follow suit to try and get a decent comparison.
There was a person who had posted about trying to use one of my videos to come up with an actual time. After that I setup a high speed camera with a counter as a reference. at 1000fps, you would watch the LCDs operate. It was fairly accurate but not very useful information, to me anyway.
I uses a opto-fet for switching a resistor in when testing DMM's, this way I avoid any noise or leak current and because it is a dual-fet I can also use it for capacitance ranges.
Instead of comparing different meters I find how long time I need to switch the resistor on before the meter will measure it correctly, this is easier to do and more precise, but it would not look as interesting on video.
My circuit: https://lygte-info.dk/info/DMMTesterACSwitch%20UK.html (https://lygte-info.dk/info/DMMTesterACSwitch%20UK.html)
You want to avoid leak current but stick a 10M probe across it?
Instead of comparing different meters I find how long time I need to switch the resistor on before the meter will measure it correctly, this is easier to do and more precise, but it would not look as interesting on video.
QuoteInstead of comparing different meters I find how long time I need to switch the resistor on before the meter will measure it correctly, this is easier to do and more precise, but it would not look as interesting on video.
I'm not understanding your above comment. If you do not time them with the scope, I doubt leakage would be a problem with these handhelds. Without the scope, I assume you monitor the settling with the display. How is what you are doing more precise. I guess I need to take the time to read your entire blog.
With your jig using a 10uF, I guess I don't see the point of the two FETs. I was looking my fixture using the first four meters and capacitance was about 1nF. Even with these large vintage FETs (I think I have some BUZ parts in there), 10uF would be no problem to switch in.
QuoteInstead of comparing different meters I find how long time I need to switch the resistor on before the meter will measure it correctly, this is easier to do and more precise, but it would not look as interesting on video.
I'm not understanding your above comment. If you do not time them with the scope, I doubt leakage would be a problem with these handhelds. Without the scope, I assume you monitor the settling with the display. How is what you are doing more precise. I guess I need to take the time to read your entire blog.
There is no reason to look at the pulse, I know the pulse with from my generator and when the pulse width is long enough for the meter to get a correct reading I have my time. With some meters this time varies a bit and I increase the time until I get a stable reading for each pulse.
With your jig using a 10uF, I guess I don't see the point of the two FETs. I was looking my fixture using the first four meters and capacitance was about 1nF. Even with these large vintage FETs (I think I have some BUZ parts in there), 10uF would be no problem to switch in.
Many meters uses some sort of AC to measure capacitors, with two FETs I switch both polarities on/off.
QuoteInstead of comparing different meters I find how long time I need to switch the resistor on before the meter will measure it correctly, this is easier to do and more precise, but it would not look as interesting on video.
I'm not understanding your above comment. If you do not time them with the scope, I doubt leakage would be a problem with these handhelds. Without the scope, I assume you monitor the settling with the display. How is what you are doing more precise. I guess I need to take the time to read your entire blog.
There is no reason to look at the pulse, I know the pulse with from my generator and when the pulse width is long enough for the meter to get a correct reading I have my time. With some meters this time varies a bit and I increase the time until I get a stable reading for each pulse.
Again, I guess I am missing the your point of it being more precise. More precise than scratching the leads? More precise than using a high speed camera with a clock for a reference?
Does it not look as interesting as what on video? Scratching the leads?
Looks like are basically doing the same thing.
With your jig using a 10uF, I guess I don't see the point of the two FETs. I was looking my fixture using the first four meters and capacitance was about 1nF. Even with these large vintage FETs (I think I have some BUZ parts in there), 10uF would be no problem to switch in.
Many meters uses some sort of AC to measure capacitors, with two FETs I switch both polarities on/off.
I assume you ran into problems with some meters when turning off the single FET and the meter still reading the 10uF or some other high value. I had looked at four of the meters using a 10uF in series with the single FET and it seemed fine. Any idea which meters had the problem with the single FET? Maybe I have one.
With my method I do multiple tests, this means I do not risk getting the fastest time the meter can do.
Looking at a couple of meter and seeing which is fastest may be more interesting for some, I like the numbers because I can compare all the meters I have tested (>100). If you measure frames you can, of course, do the same, except for continuity.
I did not bother checking capacity before I had the AC switch, only disconnecting one way may lead to errors (I have no idea if it do, I have never bother comparing).
Could you please explain how you actually get the settling time?
So you haven't checked if there was actually a problem with the single FET. More just trying to prevent a possible problem. Makes sense. Adding a capacitor may be of interest but I would like to go down to 200pF ish and up around 1000uF as most of the meters I have looked where slowest at the two extremes.
I think I get it. So you keep changing the pulse time until you find the spot where the meter is stable, triggering each time. To get any sort of precision it must take a very long time to run. If you had a way to monitor the meter (HS camera) one long pulse and you would have it.
I think I get it. So you keep changing the pulse time until you find the spot where the meter is stable, triggering each time. To get any sort of precision it must take a very long time to run. If you had a way to monitor the meter (HS camera) one long pulse and you would have it.
It takes a few minutes, precision is not really an issue (2.5s or 2.53s do not matter).
I think I get it. So you keep changing the pulse time until you find the spot where the meter is stable, triggering each time. To get any sort of precision it must take a very long time to run. If you had a way to monitor the meter (HS camera) one long pulse and you would have it.
It takes a few minutes, precision is not really an issue (2.5s or 2.53s do not matter).
30fps or 33ms would do it. Basically any cell phone should handle it. One cycle would get you there. Maybe a counter in the background for the time reference.
I am not sure it would be faster that way.
And as I have already said: The measure time varies (At least for some DMM's).
I am not sure it would be faster that way.
And as I have already said: The measure time varies (At least for some DMM's).
Does seem like with your eyes being used for the feedback, 30ms error would be conservative. Maybe not. Camera would let you run more than one meter at a time plus better precision? What meters do you have that vary?
Your using the display for visual feedback so of course the time for the meter needs to display the value is included. But the time that your eyes will detect it seems like it can vary depending on you. The time for the 789 to show the value dimly on the display vs fully on is about 100ms.
I am not sure it would be faster that way.
And as I have already said: The measure time varies (At least for some DMM's).
Does seem like with your eyes being used for the feedback, 30ms error would be conservative. Maybe not. Camera would let you run more than one meter at a time plus better precision? What meters do you have that vary?
The timing is the pulse width before the meter can read the value each time, the time the meter needs to display the value is not included.
I have not noted what meters varies, I simply adjust the time until I get a reading each cycle. With ohm the variance is usually small, but when doing continuity it easily triple (or more) the reaction time.
Your using the display for visual feedback so of course the time for the meter needs to display the value is included. But the time that your eyes will detect it seems like it can vary depending on you.
Another option, start with the grill starter, kill it in a few seconds and leave it at that.... Nice short video, right to the point. :-DD :-DD
At first glance yes. The UT61E (and probably the UT61E+) are finicky with transients but why not put it through its paces? Who knows? Perhaps it could be an additional advantage of the "plus" model...Another option, start with the grill starter, kill it in a few seconds and leave it at that.... Nice short video, right to the point. :-DD :-DD
Correct.
I mean, seriously, what is the point of testing the UT61E for "robustness"? We all know it isn't.
At first glance yes. The UT61E (and probably the UT61E+) are finicky with transients but why not put it through its paces? Who knows? Perhaps it could be an additional advantage of the "plus" model...Another option, start with the grill starter, kill it in a few seconds and leave it at that.... Nice short video, right to the point. :-DD :-DD
Correct.
I mean, seriously, what is the point of testing the UT61E for "robustness"? We all know it isn't.
Obviously that the "real" test would be with the "third party plus-certified and mega-accredited and über-listed" UT161E, but that is in another price league...
At any rate, I don't think there is much to be lost, especially after you already beaten to death the UT61E original, with excellent suggestions to increase its robustness.
(edit) Kerry Wong also did a teardown of the UT61E+
http://www.kerrywong.com/2021/04/04/teardown-of-a-uni-t-ut61e-true-rms-multimeter/ (http://www.kerrywong.com/2021/04/04/teardown-of-a-uni-t-ut61e-true-rms-multimeter/)
(edit2) Tenma has some discounts on beefed up UT61E (non plus)
https://www.eevblog.com/forum/buysellwanted/newark-sale-on-many-tenma-brand-meters/msg3655997/ (https://www.eevblog.com/forum/buysellwanted/newark-sale-on-many-tenma-brand-meters/msg3655997/)
The impact of a transient would be highly dependent on many factors - a certain Joeqsmith even said once that it is very hard to evaluate the robustness by looking at a PCB... :)At first glance yes. The UT61E (and probably the UT61E+) are finicky with transients but why not put it through its paces? Who knows? Perhaps it could be an additional advantage of the "plus" model...Another option, start with the grill starter, kill it in a few seconds and leave it at that.... Nice short video, right to the point. :-DD :-DD
Correct.
I mean, seriously, what is the point of testing the UT61E for "robustness"? We all know it isn't.
Looking at the data I've collected, of the eight UNI-T products I looked at, half never made it past the ESD, AC line tests. During the EEVBLOG review for the 61E+, Dave focuses on the lack of a surge rated resistor. The UT181A is the same and survived some decent hits after a few small changes. Dave talks about the new ground path. It could help but my guess is it won't.
Indeed ESD is a different kind of beast.Obviously that the "real" test would be with the "third party plus-certified and mega-accredited and über-listed" UT161E, but that is in another price league...
That meter would fail ESD just like the stripped down version.
And don't I know that? It seems the more effort put on a video, the lesser the audience watches thoroughly. Anything related to multimeters or consumer products goes a long way on my channel, but everything else does not go very far w.r.t. audience and retention. Or perhaps it is me. (oh, the mysteries of life...)At any rate, I don't think there is much to be lost, especially after you already beaten to death the UT61E original, with excellent suggestions to increase its robustness.
For you, skim the video for a few seconds and your done. Flip side, it takes fair amount of my time to run the tests and edit the videos. For this meter, assuming the grill starter kills it, maybe six days. Half of that would be cycling the function switch.
We could reorder the tests for this special meter. Start with the 100us transients. If it survives that (which it won't) then run the AC line test and then the ESD. Not sure we would learn anything more doing this. The end results the same.Well, every test exposes a level of weakness - the ESD is quite violent but less energy. IIRC the cert agencies are mostly concerned about the transients (or not, don't quote me on that), I would imagine more meters would survive further in your round of tests.
UNI-T fanboys are already thinking I am biased against this meter. I can see the mass of down votes. lol. I have more than enough data now to know what to expect.
Hey Joe,
i was one of the few who voted against doing these kind of videos. (Seems like years ago...)
If i could vote again, i would definitely change my answer.
Just wanted to say that your videos are awesome, please keep them coming.
Just a little question regarding the BM869s:
I am using my BM869s to discharge capacitors before working on them(Through capacitance mode). In the manual brymen only states that
large value capacitors should be discharged through an appropriate resistive load. What is your opinion on this?
Best regards,
Tim
The impact of a transient would be highly dependent on many factors - a certain Joeqsmith even said once that it is very hard to evaluate the robustness by looking at a PCB... :)
And don't I know that? It seems the more effort put on a video, the lesser the audience watches thoroughly. Anything related to multimeters or consumer products goes a long way on my channel, but everything else does not go very far w.r.t. audience and retention. Or perhaps it is me. (oh, the mysteries of life...)
I am scratching my head why the channel has so many subscribers. Ads are turned off, so YT doesn't promote it. I don't advertise outside of EEVBLOG. My videos are not released on any sort of schedule and months can go by without making one. It's maybe the worse way to run a channel. :-DD Combine all that with I am no showman. Your never going to hear: Please give it a thumbs up and join my Patreon so I can continue to bring you these high quality videos. :-DDYou did something that nobody did before, so there's that. Also, EEVBlog forums are primed for test gear, therefore solely promoting this here is already a tremendous leg up. The fact you don't give a hoot for brand loyalty is another factor. At last, a bit of controversy (the subject of this poll) stirs the audience, including the fanboys that will throw tomatoes at the screen. :-DD
Although I am monetizing my channel, I don't have any hopes of it becoming a true source of income (the first US$100 only after 13 months - yay!) and could easily gather more audience speaking a language less uncommon than Portuguese.
Pssst! I can't say it out loud...Although I am monetizing my channel, I don't have any hopes of it becoming a true source of income (the first US$100 only after 13 months - yay!) and could easily gather more audience speaking a language less uncommon than Portuguese.
You owe me a coffee. Mine just came out my nose.
The question now is how much was spent during that time? :-DD
I am scratching my head why the channel has so many subscribers. Ads are turned off, so YT doesn't promote it. I don't advertise outside of EEVBLOG. My videos are not released on any sort of schedule and months can go by without making one. It's maybe the worse way to run a channel. :-DD Combine all that with I am no showman. You're never going to hear: Please give it a thumbs up and join my Patreon so I can continue to bring you these high quality videos. :-DD
***
SP
On the video you nailed the interesting bits of the UT61 series: the lightning fast capacitance meter (the original UT61E is the king on this, even on capacitors with tens of thousands of µF) and its wide input frequency (which cooked the frequency range unfortunately). I did not improve the safety on mine since, as long as I keep it on the bench, I don't see it being cooked anytime soon. Also, the absence of an auto-power off is great.
Back to the frequency range, the UT61E+ manual (https://www.uni-trend.com/uploadfile/2020/1101/20201101050334873.pdf) indicates that frequencies above 40MHz have unspecified accuracy, thus the marketing department was very optimistic on this feature.
The manual also says the maximum input voltage at that range is derated to 20VRMS maximum, although it says it has a 1000V overvoltage protection. How many volts did you apply?
The UNI-T UT61E+
https://www.youtube.com/watch?v=4rADgFqFFH8 (https://www.youtube.com/watch?v=4rADgFqFFH8)
Prediction: The grill starter killed it... :popcorn:
I'm a bit confused: Shouldn't a hot PTC have saved the meter? Isn't that their job?
I'm a bit confused: Shouldn't a hot PTC have saved the meter? Isn't that their job?
Well, despite the PTC was cooked, the rest of the meter is intact (or should be).I'm a bit confused: Shouldn't a hot PTC have saved the meter? Isn't that their job?
At those frequencies, he basically made a Metcal soldering iron from a meter.
All the RF energy was simply dissipated inside meter as heat..
I'm a bit confused: Shouldn't a hot PTC have saved the meter? Isn't that their job?
At those frequencies, he basically made a Metcal soldering iron from a meter.
All the RF energy was simply dissipated inside meter as heat..
Well, despite the PTC was cooked, the rest of the meter is intact (or should be).
That is a whole debacle over the role that CAT ratings have in cheaper meters that supposedly are approved (UT139C, UT61E for the EU market and so on): should they survive a transient unscathed or should they only guarantee the operator survives regardless of their own functional state? The second option should be expected, but the first one is a bit in the air.
That is a whole debacle over the role that CAT ratings have in cheaper meters that supposedly are approved (UT139C, UT61E for the EU market and so on): should they survive a transient unscathed or should they only guarantee the operator survives regardless of their own functional state? The second option should be expected, but the first one is a bit in the air.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=1269721;image)
And yes the fuse is soldered in as well.
The CAT ratings are safety standards, it just has to fail safe.
I don'y recall if that's for every test in the standard, but it's the basic gist of the high energy testing.
I've provided you with quotes from the standards and how at least one of the top handheld manufacture and one of the lower tier interprets them.Precisely. It hinges on interpretation. It is not crystal clear nor set in stone.
I've provided you with quotes from the standards and how at least one of the top handheld manufacture and one of the lower tier interprets them.Precisely. It hinges on interpretation. It is not crystal clear nor set in stone.
As I also mentioned before, this is understandable as standards are comprised of various players in the industry with different goals and aiming different target prices. There is always a give and take going on at standards' commitees.
Who would ever have thought a meter with latching relays would every make it to market. There's no test for it. :-DD Have they lost their way? Seems so.
Being mechanical, relays are naturally more fragile than solid state parts for a handheld device (no issue with bench units), therefore there are chances of accelerated degradation or failure in an equipment used in a mechanically unstable environment - IIRC the standard does not have a mechanical test (although don't quote me on that). Unfortunately, I don't think there is data that shows drop tests on both types (solid state and relay) to quantify any degradation, either short or long term.Who would ever have thought a meter with latching relays would every make it to market. There's no test for it. :-DD Have they lost their way? Seems so.
I'm not clear on the problem--there have been meters in the past that have used latching relays without issues that I know of. Are you saying they are inherently problematic or that they aren't being used correctly?
William "Pete" Snell was the "Racer of the Year" when he died needlessly in a 1956 Sports Car Club of America racing event. His then state-of-the-art helmet, made of leather and pressed cardboard paper, didn’t protect him. The following year, in memory of Pete, a number of his friends, colleagues, and fellow racers, including Dr. George Snively, formed the Snell Memorial Foundation, now known as Snell Foundation. Its purpose was to set helmet performance standards to encourage the development and use of truly protective helmets.
DOT and ECE are law of the land for motorcycle helmets sold in the US and in European Union countries. Although government standards are required, they also are the minimal standards. Snell Standards demand the highest premium protection that current technology and materials can offer. Snell Standards are voluntary. Many of the best helmet manufacturers decide to design and make helmets to Snell Standards because many consumers seek out Snell certified helmets.
The CAT ratings are safety standards, it just has to fail safe.
I don'y recall if that's for every test in the standard, but it's the basic gist of the high energy testing.
IIRC, the meter must continue to indicate the presence of hazardous voltages, although it doesn't have to be accurate. This makes sense, or alternatively (not in the standards AFAIR, just my opinion) at least it should fail completely (no display) rather than indicate 0.000V. Imagine I hang my meter up at a machine I want to test and hook it up, it says 240VAC. I walk over to the service panel and turn off the wrong breaker, but there is a big transient that blows open the inputs on the meter--but doesn't cause any physical damage. I come back and my meter reads 0VAC--so I go to work. This is an argument against fused leads and also is the basis for the 'test before touch' protocol that requires that the meter be proved immediately before and after testing.
In germany, safety regulations do also not allow to check for the absence of voltage with a DMM, you are to use a 2-pole voltage tester instead. (Well known brand here is "Duspol")
Reasons:
- Due to operator error, you could misplug the cables and end up in the low-impedance input of the DMM, which causes accidents
- due to the high impedance in todays multimeters, they can measure some "stray voltage" on the wires because of some capacitic effects on long cables. A 2-pole voltage tester has buttons where you can put a low impedance on that circuit so to see if the voltage remains or under load goes down
In germany, safety regulations do also not allow to check for the absence of voltage with a DMM, you are to use a 2-pole voltage tester instead. (Well known brand here is "Duspol")
Reasons:
- Due to operator error, you could misplug the cables and end up in the low-impedance input of the DMM, which causes accidents
- due to the high impedance in todays multimeters, they can measure some "stray voltage" on the wires because of some capacitic effects on long cables. A 2-pole voltage tester has buttons where you can put a low impedance on that circuit so to see if the voltage remains or under load goes down
In germany, safety regulations do also not allow to check for the absence of voltage with a DMM, you are to use a 2-pole voltage tester instead. (Well known brand here is "Duspol")
Reasons:
- Due to operator error, you could misplug the cables and end up in the low-impedance input of the DMM, which causes accidents
- due to the high impedance in todays multimeters, they can measure some "stray voltage" on the wires because of some capacitic effects on long cables. A 2-pole voltage tester has buttons where you can put a low impedance on that circuit so to see if the voltage remains or under load goes down
What would those regulations say about a DMM that doesn't have current ranges and is fully protected on the ranges that it does have (takes care of first problem) and has a Lo-Z function?
In germany, safety regulations do also not allow to check for the absence of voltage with a DMM, you are to use a 2-pole voltage tester instead. (Well known brand here is "Duspol")
Reasons:
- Due to operator error, you could misplug the cables and end up in the low-impedance input of the DMM, which causes accidents
- due to the high impedance in todays multimeters, they can measure some "stray voltage" on the wires because of some capacitic effects on long cables. A 2-pole voltage tester has buttons where you can put a low impedance on that circuit so to see if the voltage remains or under load goes down
What would those regulations say about a DMM that doesn't have current ranges and is fully protected on the ranges that it does have (takes care of first problem) and has a Lo-Z function?
When is a multimeter not a multimeter?
https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-113 (https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-113)
When is a multimeter not a multimeter?
https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-113 (https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-113)
https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-116 (https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-116)
Hey Joe thanks for your videos! Just watched your new video about the UT61E+ as it was recommended to me (see, you do get recommended by Youtube!) :)I read your previous posts. One test I run is a taking a 220VAC, run it through bridge and apply that to the meter with it set to every mode. Sadly, you will not find where I ran a UT61E beyond the one I modified for the purpose of surviving my tests. The plan is to put the 61E+ through the normal tests but just not document any of the results due to it being slightly modified.
I'm just curious if you would be willing to make a very simple input test: give the meter 230VAC on the ohms range.
That easily killed the old model, even when it was the "GS" typerated version with beefier input protection.
You can see my thread on it linked below, I managed to kill mine twice already this way :-DD
I do realize after you changed the input protection now it might fare better, but still an interesting test I'd say, as it is an easy mistake to do.
https://www.eevblog.com/forum/repair/uni-t-ut61e-diode-mode-repair/msg3622382/#msg3622382 (https://www.eevblog.com/forum/repair/uni-t-ut61e-diode-mode-repair/msg3622382/#msg3622382)
@Joe
Hi Joe, and first, keep safe and more importantly a big THANK YOU for keeping this thread going and your fascinating testing & analysis of dozens of DMMs over the last 6 years and counting!
I have read of course the rules that you set in your first post in this thread and I hope I am not disrespecting them if I have a request for you: would it be possible for you to test this unassuming, low cost (around $15 including shipping) UNI-T UT125C DMM? What makes it different from others in the same price range is that it is apparently independently certified to conform to UL STD 61010-1, -2-030, -2-033 and -031 and rated CAT III 600V.
It's a tiny thing, comparable in size to the Brymen BM27 which you have tested, only much thicker and mechanically sturdier. Now whether it would pass your gas grill lighter test is an unknown.
I am attaching two pics of the UT125C, a top view and an internal view which shows the PTCs and MOVs and protection diodes in its input path. Curiously there is also a spark gap but the component above it is not present, so I wonder if the spark gap has any use in this case.
Thanks again for your fascinating work!
I am attaching two pics of the UT125C, a top view and an internal view which shows the PTCs and MOVs and protection diodes in its input path. Curiously there is also a spark gap but the component above it is not present, so I wonder if the spark gap has any use in this case.The thing I'm not seeing in the Uni-T is the big surge-rated resistor.
I would hope that gap is not directly across the inputs. If it is and has a UL safety cert, it would just further erode my confidence in these large bodies.
Not doubt there are some idiots who would say that meter is very robust.
The thing I'm not seeing in the Uni-T is the big surge-rated resistor.
Then there's what you are calling a spark gap. It sure does look like that's the intent with the plated edges. I would hope that gap is not directly across the inputs. If it is and has a UL safety cert, it would just further erode my confidence in these large bodies.
Another problem I see is how the meter shares the inputs with the current function. The problem there is depending how the meter is designed, the fuse may blow after each transient. For two functions, that's 20 transients for each level, or 20 fuses. I have seen meters like this before and point them out but have not ran them for this reason.IMO that is one of the worst features of any DMM. Sure, you can make the case that ultra-cheap meters cannot afford an extra input jack due to size/cost, but that is a terrible design decision for anything more serious that might be subjected to transients.
The thing I'm not seeing in the Uni-T is the big surge-rated resistor.That tends to be replaced by R46, R47 and R48. 300kΩ each.
Have you tried to find pictures of the bottom side? You may be able to trace out the front end.
If you think that Uni-T 135C is bad (and I agree with you), just be glad you haven't had the misfortune to encounter one of these turds:
Yes, there are high resolution pictures of the top and bottom sides of the UT125C PCB on HKJ's website.
If that happens, arc would exit the case following the cables.
It might.... if you used it outside the CAT III environment that it's rated for.
And where do you think CAT III is?
On the safest side of a distribution panel with circuit breakers in it.
We still don't know for sure if what we're looking at is a spark gap or where it is in the meter's input circuit, eg. Is it in series with the fuse? To me it looks like there could be a current shunt across that gap in some variant of the mater (between the two vias where the vertical white line is painted).
If that happens, arc would exit the case following the cables.
It might.... if you used it outside the CAT III environment that it's rated for.
Yes, there are high resolution pictures of the top and bottom sides of the UT125C PCB on HKJ's website.
Can you pop the fuse out and confirm which end the positive lead is connected to?
Edit: it appears from one of HKJ's other photos that it is connected to the top (near the PTCs) as one would hope.
...
We still don't know for sure if what we're looking at is a spark gap or where it is in the meter's input circuit, eg. Is it in series with the fuse?
...
... (insulation is badly damaged on cables on that photo..) ...
Yes, the positive lead is connected to the side of the fuse that meets the PTCs. So I would guess if ever there is a transient that arcs across the gap, it should blow the fuse?
...
So here is a plausible example. Suppose you have a large machine that uses 10 of these motors:
...
...
A phase-to-phase fault on a 480-V system with 20,000 amperes of fault current provides 9600000 watts of power (9,6 MW).
...
Yes, there are high resolution pictures of the top and bottom sides of the UT125C PCB on HKJ's website.
Can you pop the fuse out and confirm which end the positive lead is connected to?
Edit: it appears from one of HKJ's other photos that it is connected to the top (near the PTCs) as one would hope.
Yes, the positive lead is connected to the side of the fuse that meets the PTCs. So I would guess if ever there is a transient that arcs across the gap, it should blow the fuse?
...
So here is a plausible example. Suppose you have a large machine that uses 10 of these motors:
......
A phase-to-phase fault on a 480-V system with 20,000 amperes of fault current provides 9600000 watts of power (9,6 MW).
...
Excluding the apocalyptic scenarios, we are talking about a $15 10cm tall DMM for home use, certainly not an electrician's tool for use in industrial settings. All I am interested in is that it is independently certified to a CAT III 600V rating. And of course I am curious about the spark gap. Btw if you look closely it also has a PCB cutout under the (beefy?) PTCs. So it seems that UNI-T spent a few extra cents to try to meet the CAT III rating, but was the effort and money well spent?
...It will blow the fuse, but they are slow devices. ...
Yes, the positive lead is connected to the side of the fuse that meets the PTCs. So I would guess if ever there is a transient that arcs across the gap, it should blow the fuse?
All I am interested in is that it is independently certified to a CAT III 600V rating.
...It will blow the fuse, but they are slow devices. ...
Yes, the positive lead is connected to the side of the fuse that meets the PTCs. So I would guess if ever there is a transient that arcs across the gap, it should blow the fuse?
I believe there is a PTC+MOV in parallel with the spark gap + fuse across the input leads, shouldn't that react faster than the fuse?
So the transient energy would be absorbed in two steps, first by the PTC+MOV combo and then eventually second, by arcing across the spark gap and blowing the fuse?
I haven't measured the width of the spark gap but it seems to be about 1mm to 1.5mm wide, so the transient would need to be above 3kV to 4.5kV to arc across it, or am I getting it wrong?
I believe there is a PTC+MOV in parallel with the spark gap + fuse across the input leads, shouldn't that react faster than the fuse?
I haven't measured the width of the spark gap but it seems to be about 1mm to 1.5mm wide, so the transient would need to be above 3kV to 4.5kV to arc across it, or am I getting it wrong?
Btw if you look closely it also has a PCB cutout under the (beefy?) PTCs.
...., but Germans being traditionally thorough, ....
A phase-to-phase fault on a 480-V system with 20,000 amperes of fault current provides 9600000 watts of power (9,6 MW). If the fault lasts for 200 milliseconds before the overcurrent protection clears it, the released energy would be 1,92 MJ, which corresponds roughly to a stick of dynamite.
if it turns out that it got that CAT III/600V rating through entirely legitimate means, then the CAT ratings themselves are not a very strong indication of anything. And that is bad for everyone, IMO.
With arc accidents, it is not transient that does damage. Transient creates plasma that creates short fault.
And power grid powers the explosion
...
:-DD As I stated, there's nothing there to save the PTCs except the PCB and leads. Maybe the MOVs would open up first.
...
Those surge rated resistors are expensive. Lets just put two 5mm PTCs in series. What could go wrong?
IIRC the CATIII 600V rating means the DUT has to withstand 10 repeated transients, so if the PTC fails catastrophically after the first or second transient, the DUT does not get the rating?
...
:-DD As I stated, there's nothing there to save the PTCs except the PCB and leads. Maybe the MOVs would open up first.
...
Those surge rated resistors are expensive. Lets just put two 5mm PTCs in series. What could go wrong?
I think I understand: a surge rated resistor is needed in series with the PTC, to absorb part of the energy of the transient until the PTC has enough time to heat up and see its resistance value increase. If there is no surge rated resistor, the PTC absorbs all the energy of the transient before its resistance value has enough time to increase and could eventually fail catastrophically.
IIRC the CATIII 600V rating means the DUT has to withstand 10 repeated transients, so if the PTC fails catastrophically after the first or second transient, the DUT does not get the rating?
CAT ratings have many grey areas. It's easy to invent worst-case scenarios for any category.
I'm not going to pretend to understand them but I'll happily point out that a CAT III 600V rating isn't automatically a CAT IV 300V rating even though they both say "6000V @ 2 Ohms" in the cute little chart.
The way I understand it is that the standards only say that the meter has to fail in a safe manner.
ie. the PTC can explode during the first transient and it still gets the rating if no shrapnel penetrates the case.
...
It seems you feel that the transients I apply cause the PTCs to switch. I have no idea why you would feel this way, but I've made whole videos on this subject. You could also look at the datasheets for various PTCs and see what are the effects of various package sizes.
...
as discussed elsewhere:
"After the voltage of 4.4.2.101 has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
NOTE The METER is not required to maintain its normal accuracy. A maximum deviation of 10 % is acceptable."
"Conformity is checked by inspection while applying the maximum RATED voltage of each voltage measurement range capable of MAINS voltage measurements."
as discussed elsewhere:
"After the voltage of 4.4.2.101 has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
NOTE The METER is not required to maintain its normal accuracy. A maximum deviation of 10 % is acceptable."
I note you've missed out the next part of that text, which says:Quote"Conformity is checked by inspection while applying the maximum RATED voltage of each voltage measurement range capable of MAINS voltage measurements."
The PTCs aren't on the "voltage measurement" part of a multimeter circuit, they're on the much lower-impedance "ohms/continuity/etc" part of the circuit.
Ref: https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/100/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/100/)
as discussed elsewhere:
"After the voltage of 4.4.2.101 has been applied to the METER, the METER shall continue to be
able to indicate the presence of HAZARDOUS LIVE voltages up to the maximum RATED voltage.
NOTE The METER is not required to maintain its normal accuracy. A maximum deviation of 10 % is acceptable."
I note you've missed out the next part of that text, which says:Quote"Conformity is checked by inspection while applying the maximum RATED voltage of each voltage measurement range capable of MAINS voltage measurements."
The PTCs aren't on the "voltage measurement" part of a multimeter circuit, they're on the much lower-impedance "ohms/continuity/etc" part of the circuit.
Ref: https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/100/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/100/)
And where do you think CAT III is?
On the safest side of a distribution panel with circuit breakers in it.
I note you've missed out the next part of that text, which says:Quote"Conformity is checked by inspection while applying the maximum RATED voltage of each voltage measurement range capable of MAINS voltage measurements."
The PTCs aren't on the "voltage measurement" part of a multimeter circuit, they're on the much lower-impedance "ohms/continuity/etc" part of the circuit.
...Either you should set aside the equivalent to 15€ or you can lose all faith in independent certification companies. Because Intertek has indeed tested the UT125C. I found the UT125C in their directory, here:
If that UNI-T can actually read mains voltage after being subject to 10 strokes of whatever transient most closely matches the CAT III/600V 6kV/2ohm IEC model, I'll buy one.
But, aren't they prior to the range switch, and therefore part of the circuitry in play when in the volts ranges?[/b]
The PTCs aren't on the "voltage measurement" part of a multimeter circuit, they're on the much lower-impedance "ohms/continuity/etc" part of the circuit.
No, I didn't miss that. However, on the UNI-T we are trashing, one of the PTCs is in series with the voltage circuit and since there is no surge resistor, when the 2 MOVs clamp it will be roasted just as badly as if it were in series with another low-impedance circuit. If that UNI-T can actually read mains voltage after being subject to 10 strokes of whatever transient most closely matches the CAT III/600V 6kV/2ohm IEC model, I'll buy one.
Either you should set aside the equivalent to 15€ or you can lose all faith in independent certification companies. Because Intertek has indeed tested the UT125C. I found the UT125C in their directory, here:
I haven't looked closely at this particular Uni-T but generally multimeters have a separate 10MOhm voltage input and a 10kOhm+PTC resistance/continuity input.
The PTCs aren't on the "voltage measurement" part of a multimeter circuit, they're on the much lower-impedance "ohms/continuity/etc" part of the circuit.
No, I didn't miss that. However, on the UNI-T we are trashing, one of the PTCs is in series with the voltage circuit and since there is no surge resistor, when the 2 MOVs clamp it will be roasted just as badly as if it were in series with another low-impedance circuit. If that UNI-T can actually read mains voltage after being subject to 10 strokes of whatever transient most closely matches the CAT III/600V 6kV/2ohm IEC model, I'll buy one.
I haven't looked closely at this particular Uni-T but generally multimeters have a separate 10MOhm voltage input and a 10kOhm+PTC resistance/continuity input.
Keep those stories coming. We're here all night folks.
Either you should set aside the equivalent to 15€ or you can lose all faith in independent certification companies. Because Intertek has indeed tested the UT125C. I found the UT125C in their directory, here:
I would happily spend the $22 to have my faith renewed in the certification process and gain a reliable meter that I don't need in the process. Unfortunately I'm anticipating being disappointed by the Intertek Shenzen branch--or somebody, anyway.
Keep those stories coming. We're here all night folks.
I'm having a moment, aren't I?
I suspect you have been looking at too many low end meters like the UNI-T, ANENG.... Your statement about "...generally multimeters have a separate 10MOhm voltage input.." could be correct
I suspect you have been looking at too many low end meters like the UNI-T, ANENG.... Your statement about "...generally multimeters have a separate 10MOhm voltage input.." could be correct
Yeah, the only ones I've sat and traced out (a couple of years ago) were cheapies and the voltage input went straight to the 10MOhm resistor chain with a separate branch where the 10K resistor and (single) PTC was.
I've just watched this again and I'm all edumacated now:
...
The meter in that video^ (Fluke 27) also has two input branches, one with just a resistor before it goes off to the ADC. :popcorn:
The meter in that video^ (Fluke 27) has two input branches, one with only a resistor before it goes off to the ADC. :popcorn:
3. Intertek has countless offices in China, 13 of which are located in Shenzhen. https://www.intertek.com/contact/asiapacific/china/ (https://www.intertek.com/contact/asiapacific/china/)
2. Shenzhen (please note the correct spelling) is a modern, prosperous city of nearly 13 million, including thousands of permanently resident foreigners.
1. Intertek has certified the UNI-T UT125C.
CAT III is already a serious place. It is circuit just after or on fuse panel. High fault currents are still possible.
For instance you have an 200kW elevator motor, that one would be CAT III because it is behind junction box and has a fuse.
A phase-to-phase fault on a 480-V system with 20,000 amperes of fault current provides 9600000 watts of power (9,6 MW). If the fault lasts for 200 milliseconds before the overcurrent protection clears it, the released energy would be 1,92 MJ, which corresponds roughly to a stick of dynamite.
At 20000A current, at a distance of 0.5 m, light intensity might reach magnitude of about 1,8 M lux!
Fault currents in CAT III can be up to 25kA... I assure you that is a serious arc fault accident.
The Mersen lab has two generators. Each generator is rated 10 megavolt-amperes (MVA) continuous with a short-circuit rating of 68 MVA and is powered by a 4,160-volt (V), 536-horsepower electric motor that is directly connected to the utility. When a test is conducted, the short-circuit current comes from the generator and not the electric utility.
This lab has the capability to produce up to 100,000A of short-circuit current at 480V.
...
How is this relevant to the issue at hand?
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Apart from your "anticipating being disappointed by the Intertek Shenzen (sic) branch", do you have anything to say based on facts relevant to the issue at hand?
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Yep. There's a bunch of Aneng meters that are "certified" with downloadable certification certificates but one look a the PCB will tell you it's lie.
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.... If it were, we would all be experts at everything. ...
.... If it were, we would all be experts at everything. ...
We are!
https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols (https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols)
1. "one look at the PCB" is not enough for much. If it were, we would all be experts at everything. Ah, but I forgot: you are an (self-proclaimed) expert... :-DD
2. What exactly do you claim is a lie?
We are!
https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols (https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols)
Joe: If I'm reading it right this is a meter where the input goes directly from the volts jack to the IC with only R16 and R17 in between. The PTC is on a separate circuit (after going through the range switch!)
The fact that Intertek has certified the UNI-T UT125C is certainly relevant to the issue at hand. But the baseless or irrelevant dribble you posted certainly isn't.
Apart from your "anticipating being disappointed by the Intertek Shenzen (sic) branch", do you have anything to say based on facts relevant to the issue at hand?
1. "one look at the PCB" is not enough for much. If it were, we would all be experts at everything. Ah, but I forgot: you are an (self-proclaimed) expert...
perhaps refrain from the baseless claims and "anticipating being disappointed" sort of comments a little bit?
Free meters!!! It's been a while since anyone has "reached out" to me with such an offer.
... you can certainly spot creepage and clearance insufficiencies.
Free meters!!! It's been a while since anyone has "reached out" to me with such an offer.
I'm torn. You could accept it and zap it.
Was it Dave or you that did a bad 'review' of something and the manufacturer put it on their web page anyway? I don't remember. :-DD
(Bad meter! Bad!)
HIOKI also "reached out" to me a while ago. I use some of their equipment for industrial work. I don't believe they are certified. :scared:
And to be clear, you're suggesting that ALL of the Chinese do not?HIOKI also "reached out" to me a while ago. I use some of their equipment for industrial work. I don't believe they are certified. :scared:
That's common for the Japanese meters, they do self certification to the standard.
But as opposed to the Chinse companies, the Japanese actually do do it and take it seriously.
HIOKI also "reached out" to me a while ago. I use some of their equipment for industrial work. I don't believe they are certified. :scared:
That's common for the Japanese meters, they do self certification to the standard.
But as opposed to the Chinse companies, the Japanese actually do do it and take it seriously.
That's common for the Japanese meters, they do self certification to the standard.I'm not sure about that - I'd emailed Sanwa and Hioki asking for Certificate of Conformance or any proof about their multimeter 61010 claims.
ANENG 61010 certificate is just for a 3V battery-powered device, no hazardous energy connected to it. chinese reports can be very hokey, skipping many tests.
Engineers can design to their heart's content and think it's all good- but testing is done to prove the PC board spacings are adequate, components etc. work and it stays reasonably safe.
...You don't actually know that for sure, do you? Unless you have worked with any DMM manufacturer development team at any point in your life, which I am certain you didn't...
No, they have a room full of meter zapping equipment and test it themselves at every stage during development. Find the weak points and eliminate them. Third party testing only happens after the meter is fully production-ready.
Hioki just skips the last step.
...You don't actually know that for sure, do you? Unless you have worked with any DMM manufacturer development team at any point in your life, which I am certain you didn't...
No, they have a room full of meter zapping equipment and test it themselves at every stage during development. Find the weak points and eliminate them. Third party testing only happens after the meter is fully production-ready.
Hioki just skips the last step.
"Internal conformance testing" just what is this exactly? The Honour System.
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A good question would be: is there any verified information how many industrial accidents were caused by using UNI-T meters..?
A research, by numbers, how much more accidents happen by using UNI-T than Fluke?
I would like to see that information..
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I choose to believe it because:
a) Hioki are reputable in the same way that Fluke/Brymen/Amprobe are reputable.
b) They don't sell meters for $25 on Aliexpress
c) I've seen Hioki Teardowns
d) Joe's zapped some Hiokis
e) Dave says Hioki do the internal testing
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A good question would be: is there any verified information how many industrial accidents were caused by using UNI-T meters..?
A research, by numbers, how much more accidents happen by using UNI-T than Fluke?
I would like to see that information..
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In your dreams. Please be realistic, who would pay for such information to be researched and published, and in any case, how would you guarantee that the information wouldn't be "fudged"?
This is exactly why we have mandated safety standards and independent testing and certification companies. And it is also exactly why we, as consumers, should prefer products that are independently tested and certified vs. products that are not.
:-DD Thanks for a good laugh! c) above is absolutely priceless!
Feel free to point out any safety issues:The batteries are a choking hazard and the supplied leads use probes that are very sharp. They have fuses that can easily be jumped out. I also suspect they use materials known by the state of CA to cause cancer.
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Feel free to point out any safety issues:
( links to two YouTube videos )
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which is safer, a Chinese product certified by Intertek or a self certified Japanese product?
Which is safer, a self-certified 200€ Japanese CAT IV 600V DMM that is the subject of two YouTube videos
Which is safer, a self-certified 200€ Japanese CAT IV 600V DMM that is the subject of two YouTube videos
Joe's video clearly says "Part 1 of 3" in the title, so that's at least four videos.
A good question would be: is there any verified information how many industrial accidents were caused by using UNI-T meters..?
A research, by numbers, how much more accidents happen by using UNI-T than Fluke?
I would like to see that information..
Which is safer, a self-certified 200€ Japanese CAT IV 600V DMM that is the subject of two YouTube videos
Joe's video clearly says "Part 1 of 3" in the title, so that's at least four videos.
People here should realize that most consumers do not take apart their DMMs, etc when they get them to check the internals, they just use them as is. And almost all of us are totally incapable of judging the safety or robustness or standards compliance of a DMM, even when we have it taken apart in front of our eyes.
Imo independent testing and certification is a valuable step in bringing a DMM or any piece of test equipment to market, and every DMM review should clearly state whether the device reviewed has been independently tested and certified or not, to what standards, and by which independent certification company. Whether this will actually encourage manufacturers to get their products certified is another question, but it would be a step, however small, in the right direction.
The blanket statement that independent certification is "worthless" is, imo, a step in the wrong direction. Also, any certificate can be "fudged", that applies to just about anything, from DMMs to diesel engines to jets. The question is whether it is worth it to "fudge" the certificate and risk being exposed. Personally I'll never buy another VW car or fly in a 737-MAX, but that's just me and it seems I am a rather rare case.
Feel free to point out any safety issues:joeqsmith says his content and this thread is not about safety, it's about robustness.
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Well apparently if you buy UNI-T you better take it apart to make sure they haven't omitted parts in production that were needed to get their 'certification'. And no, we aren't "totally incapable" of observing that one product uses carefully matched isolation slots and internal shielding, has larger PTCs, uses higher interrupt rated fuses, observes published creepage and clearance requirements, etc etc--and another product doesn't do all that. Of course it is true that we generally don't have any concrete means of correlating those features to actual performance on a particular test, but as a relative comparison tool I don't see the problem. I don't buy the notion that consumers should make their choices solely or even primarily on the results if this sort of testing or 'level' of certification--even if the results aren't fake.
Kreosan had some fun with their transient testing which included mains, might be worth figuring out.
And no, we aren't "totally incapable" of observing that one product uses carefully matched isolation slots and internal shielding, has larger PTCs, uses higher interrupt rated fuses, observes published creepage and clearance requirements, etc etc--and another product doesn't do all that.
Well that is your opinion which you are naturally entitled to, and it seems it is based on how you compare your own expertise vs that of entire teams of electronics engineers that do testing day in, day out with special-purpose equipment in dedicated labs.
jeoeqsmith says his content and this thread is not about safety, it's about robustness.
The follow-through current is zero. It's mains transient testing minus the mains. So a GDT looks wonderful, when it's actually not.
Kreosan had some fun with their transient testing which included mains, might be worth figuring out.
jeoeqsmith says his content and this thread is not about safety, it's about robustness.
The follow-through current is zero. It's mains transient testing minus the mains. So a GDT looks wonderful, when it's actually not.
Kreosan had some fun with their transient testing which included mains, might be worth figuring out.
jeoeqsmith says his content and this thread is not about safety, it's about robustness.
how you compare your own expertise vs that of entire teams of electronics engineers that do testing day in, day out with special-purpose equipment in dedicated labs.
I am such an idiot, I prefer to rely on independent certification processes.
You misunderstood. The teams I was referring to are the testing teams at certification companies, who you seem to believe don't exist or don't matter. As to comparing yourself to the teams that develop testing equipment at any of the major manufacturers, well... I'll leave you to your delusions of grandeur. :-DDhow you compare your own expertise vs that of entire teams of electronics engineers that do testing day in, day out with special-purpose equipment in dedicated labs....
I don't compare or equate my expertise or observations with "entire teams of electronics engineers that do testing day in, day out with special-purpose equipment in dedicated labs", in fact I like working on and repairing equipment designed by such people because I can admire and learn from their efforts.
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If we're saying that it isn't about 'safety' as in industrial arc-flash accidents, then I'd agree, these evaluations aren't conclusive.
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You misunderstood. The teams I was referring to are the testing teams at certification companies, who you seem to believe don't exist or don't matter.
As to comparing yourself to the teams that develop testing equipment at any of the major manufacturers, well... I'll leave you to your delusions of grandeur. :-DD
jeoeqsmith says his content and this thread is not about safety, it's about robustness.
The follow-through current is zero. It's mains transient testing minus the mains. So a GDT looks wonderful, when it's actually not.
Kreosan had some fun with their transient testing which included mains, might be worth figuring out.
Your first sentence is true but the bolded statement is not accurate. I use the open circuit voltage waveform but with 2X the FWHH. The short circuited current is limited to about 20J max. Even with no AC lines, the transients I apply are no where near the energy of what the actual IEC surge standards call for. Again, that was never a goal. While I can continue to correct these statements for another four years, there are going to be those who never understand it. Their expert opinions will continue to fuel the confusion. Those average Americans anyway... Oh wait... :-DD :-DD
Again, I want to be very clear that the IEC surge has nothing to do with arc-flash. And while I based my open circuit voltage waveform on the IEC surge open circuit waveform, that's about all they have in common. Comparing anything I show to a surge test shows a total lack of understanding. Thinking it has anything to do with arc flash testing is a whole new level.
Is your goal theoretical robustness or real-world, or theatrical robustness lol. I think even us non-Americans can appreciate the differences.
Mains transients are superimposed on the sine-wave, so any crowbar (i.e. GDT) action will last for a long time, not mere usec but msec. Typically 1/2 cycle to zero-cross but much worse when there is copper vapor and soot to clear. Cat. III can have high fault currents for the long duration which is the safety issue I am trying to point out, but you seem to be missing.
Again, I want to be very clear that the IEC surge has nothing to do with arc-flash. And while I based my open circuit voltage waveform on the IEC surge open circuit waveform, that's about all they have in common. Comparing anything I show to a surge test shows a total lack of understanding. Thinking it has anything to do with arc flash testing is a whole new level.
I'm not sure 'nothing to do with' is a fair assessment.
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And to be clear, you're suggesting that ALL of the Chinese do not?HIOKI also "reached out" to me a while ago. I use some of their equipment for industrial work. I don't believe they are certified. :scared:
That's common for the Japanese meters, they do self certification to the standard.
But as opposed to the Chinse companies, the Japanese actually do do it and take it seriously.
As long as we are making broad statements, I'm curious to know your opinion which is safer, a Chinese product certified by Intertek or a self certified Japanese product?
[/quote]HIOKI also "reached out" to me a while ago. I use some of their equipment for industrial work. I don't believe they are certified. :scared:That's common for the Japanese meters, they do self certification to the standard.
There's no way I would touch that one but I thought you may take a swing at it. :-DDQuoteAs long as we are making broad statements, I'm curious to know your opinion which is safer, a Chinese product certified by Intertek or a self certified Japanese product?I'm not playing your game, sorry.
No, you just don't get it. I don't compare or equate my expertise or observations with "entire teams of electronics engineers that do testing day in, day out with special-purpose equipment in dedicated labs", in fact I like working on and repairing equipment designed by such people because I can admire and learn from their efforts. However, I don't confuse high-quality products made by such companies with rubbish hacked together on a shoestring by third rate hacks.
There's no way I would touch that one but I thought you may take a swing at it. :-DDQuoteAs long as we are making broad statements, I'm curious to know your opinion which is safer, a Chinese product certified by Intertek or a self certified Japanese product?I'm not playing your game, sorry.
As long as I am thinking about it, a member had asked about connecting the UT61E+ to the 220V mains with it set to the resistance mode. I had checked your review and you did not run that test. Because I had already damaged the one I bought, any way to talk you into running it with yours?
No, you just don't get it. I don't compare or equate my expertise or observations with "entire teams of electronics engineers that do testing day in, day out with special-purpose equipment in dedicated labs", in fact I like working on and repairing equipment designed by such people because I can admire and learn from their efforts. However, I don't confuse high-quality products made by such companies with rubbish hacked together on a shoestring by third rate hacks.
Do you learn nothing from people who are asked to make a full size multimeter at a $25 price point?
If anything, it's more difficult then working on a massive budget to make a "high quality" meter.There's no way I would touch that one but I thought you may take a swing at it. :-DDQuoteAs long as we are making broad statements, I'm curious to know your opinion which is safer, a Chinese product certified by Intertek or a self certified Japanese product?I'm not playing your game, sorry.
Yep. Anbody that frames this as "China vs. Japan" instead of "Uni-T vs. Hioki" is at the Donald Trump level of debate.
Do you learn nothing from people who are asked to make a full size multimeter at a $25 price point?
If anything, it's more difficult then working on a massive budget to make a "high quality" meter.
As long as I am thinking about it, a member had asked about connecting the UT61E+ to the 220V mains with it set to the resistance mode. I had checked your review and you did not run that test. Because I had already damaged the one I bought, any way to talk you into running it with yours?
Left on for 10 seconds, survives just fine at the nominal 245V here. Readings a smidge low as the PTC recovers.
The damaged meter was a Dick Smith Q1425 and has a 40 pin ICL7106CPL dated 10/94 so almost 27 years old but in immaculate condition for its age.
I evaluated several meters on my channel and, although I don't apply an untamed outlet-level power supply on them, I use a reduced 80~90V current-limited source to get an idea of a meter's survivability in case of wrong selection by a user - a much more common case of multimeter failure (when compared to transients) among the folks that watch my channel. Even at that ridiculously low level, several meters failed this specific test with weird behaviour such as resetting, powering down, beeping uncontrollably, etc., giving a hint about its survivability.As long as I am thinking about it, a member had asked about connecting the UT61E+ to the 220V mains with it set to the resistance mode. I had checked your review and you did not run that test. Because I had already damaged the one I bought, any way to talk you into running it with yours?
Left on for 10 seconds, survives just fine at the nominal 245V here. Readings a smidge low as the PTC recovers.
Thanks. I tried running mine 300VACRMS 60Hz and it also survived.
Well it is OT but because you linked it, I think what he describes there is also a good case for a good general education with a broad spectrum even if most of that knowledge will never be needed for for an employment..... If it were, we would all be experts at everything. ...
We are!
https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols (https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols)
I have had a few people ask me about testing AC line devices which point to just how ignorant some viewers are. I don't see that changing although I run into it less and less.
The damaged meter was a Dick Smith Q1425 and has a 40 pin ICL7106CPL dated 10/94 so almost 27 years old but in immaculate condition for its age.Another 10 years or so and it would probably have been manufactured in Japan.
...So our views coincide on the matter of independent certification.
Is it a third party independent testing a better scenario than self-certification or reputation alone? Yes, of course, especially since most people don't understand the technicalities of what they are buying
- unfortunately this hasn't been he ideal scenario as time and time again it has been proven it is caveat emptor. That is why youtube and the internet have been acting as a "fourth party" source of information.The problem with relying on information from YouTube or any other form of social media rather than information from independent testing and certification companies is quite obvious to me. If you have to take any information from independent testing and certification companies with a grain of salt, information on social media requires a truckload of skepticism and common sense - and time. Since I don't have much common sense and very little time, I always prefer to rely on information from independent testing and certification companies, however flawed it may prove to be in some cases.
Well it is OT but because you linked it, I think what he describes there is also a good case for a good general education with a broad spectrum even if most of that knowledge will never be needed for for an employment..... If it were, we would all be experts at everything. ...
We are!
https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols (https://www.harvardmagazine.com/2018/03/death-of-expertise-by-tom-nichols)
Of course "social" media oppinion bubbles just makes the situation much worse.
I have had a few people ask me about testing AC line devices which point to just how ignorant some viewers are. I don't see that changing although I run into it less and less.
I don't know what the "ignorant" people asked from you, but both general household appliances, and especially the common surge protectors are a very interesting topic with all sensitive elctronics to find in an everage household. And the protection itself is very similar to what you can find in the multimeter.
So though you would of course classify me as ignorant too, but I would be really interested in both how an appliance (can be anything like a modern washing machine control board) behaves just with a 2-3000 V small voltage spike what your generator outputs, what different surge protectors let through, and of course what happens if a surge protector really meets with its thaoretical 30-70Ka rating.
(Yes I know that it is not your generator...)
Possibly a huge amount af goods is getting damaged because of this, even without any serious lightning strike or similar big issue.
Another 10 years or so and it would probably have been manufactured in Japan."all the best stuff is made in Japan..."
I am not aware of any appliances that use surge rated resistors in series with PTC and then shunted with MOVs, with selectable low voltage clamps made from back to back transistors. I have had people write me about running my tests too fast and over heating the MOVs in the DMMs.
People have asked me about running devices which would attach to the mains like power supplies and surge protectors across my generator. Yes, very ignorant. Sadly, the people who ask I expect lack the basic education to understand even the basics of what has been shown, so I don't see an easy fix.
The problem with relying on information from YouTube or any other form of social media rather than information from independent testing and certification companies is quite obvious to me. If you have to take any information from independent testing and certification companies with a grain of salt, information on social media requires a truckload of skepticism and common sense - and time. Since I don't have much common sense and very little time, I always prefer to rely on information from independent testing and certification companies, however flawed it may prove to be in some cases.
Left on for 10 seconds, survives just fine at the nominal 245V here. Readings a smidge low as the PTC recovers.
Left on for 10 seconds, survives just fine at the nominal 245V here. Readings a smidge low as the PTC recovers.
So I'm curious about why these tests would be conducted at those levels on meters with a CAT-anything label at. Should the meter not withstand, without damage, the application of full rated voltage (1000V in this case) to any input on any setting?
Indeed. Why wouldn't someone want a reliable third party that verifies a manufacturer's claims in a very reproducible, reliable and uncompromised way? We don't have this today. That is the gist of the discussion....So our views coincide on the matter of independent certification.
Is it a third party independent testing a better scenario than self-certification or reputation alone? Yes, of course, especially since most people don't understand the technicalities of what they are buying
I fully understand your stance, as there are things in life that I have to rely on an evaluation from a cert or government agency - food, utilities (gas, water) and pharmaceuticals being a few of them. Regardless, it only takes you to get burned once or twice by a product that was supposedly evaluated from these agencies to make you get smart about it. Examples galore, both in this thread with something of a niche product such as a multimeter and of more general public interest, such as the scandal where several cities in the state of Michigan had lead poisoned water for decades.- unfortunately this hasn't been he ideal scenario as time and time again it has been proven it is caveat emptor. That is why youtube and the internet have been acting as a "fourth party" source of information.The problem with relying on information from YouTube or any other form of social media rather than information from independent testing and certification companies is quite obvious to me. If you have to take any information from independent testing and certification companies with a grain of salt, information on social media requires a truckload of skepticism and common sense - and time. Since I don't have much common sense and very little time, I always prefer to rely on information from independent testing and certification companies, however flawed it may prove to be in some cases.
That's the theory but you never know for sure.
I understand that it is not exacly the same setup...
Left on for 10 seconds, survives just fine at the nominal 245V here. Readings a smidge low as the PTC recovers.
So I'm curious about why these tests would be conducted at those levels on meters with a CAT-anything label at. Should the meter not withstand, without damage, the application of full rated voltage (1000V in this case) to any input on any setting? AFAIK, even supposedly fragile CAT I bench meters will pass that test. Some older pre-CAT bench meters have separate, lower specifications for voltage protection on ohms and such, but even the old Fluke 8842A will pass that test.
I'm referring to meters that some claim to be properly rated, not ones where there isn't any dispute that the CAT info printed on them is a bad joke.
Again, they are not even close. And again, the generator was designed not to simulate AC mains conditions, or anything even close to it.
Some of the smaller PTCs are only rated for 500V. Some meters have only a single PTC which if the low voltage clamp is active, will have well over 900V across them.... Maybe.... Turn the dial, I suspect you will get a light show.
So you are suggest to use a high pot tester across the meter with it set to the volts mode?Again, they are not even close. And again, the generator was designed not to simulate AC mains conditions, or anything even close to it.
Do they need to be? HiPot testing is a valid method of looking at potential HV breakdown (obviously not L-L in a normal operating mode) without riding on any mains, so why not consider it as transient HiPot method? It certainly would at least be a usable diagnostic tool that can be used to non-destructively find weak points. One would have to learn how to interpret the results just like you do with an old engine analyzer ignition scope.
Some of the smaller PTCs are only rated for 500V. Some meters have only a single PTC which if the low voltage clamp is active, will have well over 900V across them.... Maybe.... Turn the dial, I suspect you will get a light show.
Well that doesn't sound very robust! I don't know if that is a failure to meet a standard or not, but it seems like a basic expectation to me. Every CAT labelled meter I currently have that isn't known junk should pass that test. Some of them already have by accident.
So you are suggest to use a high pot tester across the meter with it set to the volts mode?
I've seen a few people post videos (including Dave) using an insulation tester.
There was a guy posting about using a stun gun to test meters. I wrote them but they never responded.
Another option would be to actually get a combo generator tied to the mains and a nice blast shield.
All fun ideas and if anyone starts a channel where they run the meters this way, I will watch.
What would be the most important difference with a mains voltage spike with lets say 3000V P-P with the same energy level that your generator creates, to a spike 3000V p-p with your generator?
Just because it is half wave? There are no half wave spikes on the AC line?
But to turn around the argumentation, if the effects of spikes on the mains are so different(same joule level), than your generator shoud simulate rather those, because those will most likely hit the meter.
But you see I am that kind of ignorant who is trying to get an expert oppinion even if seek a bit more detailed one :)
Edit: Or what you could mean the aftermath of the possible shorts with main condition? Because like bdunham7 says after any breakdown(or letting through spikes) the interpretation is up to the viewer.
[...] Some of the smaller PTCs are only rated for 500V. Some meters have only a single PTC which if the low voltage clamp is active, will have well over 900V across them.... Maybe.... [...]
I understand. Still disconcerting the UT61E+ LCD display flickering during the BBQ lighter tests, it might be an EMC issue. I hope the IC is not getting damaged.
One could look at the input current to a multimeter during an ohms-function overload, to see the PTC heat up and settle. ...
I suspect the thermal mass of the PTCs prevent it from responding to the transients I apply.
What would be the most important difference with a mains voltage spike with lets say 3000V P-P with the same energy level that your generator creates, to a spike 3000V p-p with your generator?
The short circuit current waveform will not be even remotely close to correct, the FWHH is twice what is called out, lack of a coupling network, lack of a way to synchronize it or change the phase, lack of polarity selection, lack of support for both 50/60 Hz, lack of ability to select the mains amplitude. I think I would also like to run burst as well as surge. There are also several other tests that would be performed.Just because it is half wave? There are no half wave spikes on the AC line?
But to turn around the argumentation, if the effects of spikes on the mains are so different(same joule level), than your generator shoud simulate rather those, because those will most likely hit the meter.
Where did you get the idea that they have the same energy levels? You assume I am using these meters on the mains. I've been pretty clear about that. While there are standards in place for qualifying various devices for mains use, this is not what I have been showing over the last few years.But you see I am that kind of ignorant who is trying to get an expert oppinion even if seek a bit more detailed one :)
Edit: Or what you could mean the aftermath of the possible shorts with main condition? Because like bdunham7 says after any breakdown(or letting through spikes) the interpretation is up to the viewer.
Your opinion is that the waveforms I use to test the meters are adequate to test mains devices. My opinion is that you're ignorant on AC mains testing. Of course, you could start doing some research if it interests you and correct that deficiency but you will not find many details in this thread about it.
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I certainly agree that thesignal-to-noisenoise to signal ratio on YouTube, or even EEVBlog can be quite high. But you make it seem as if there are only two choices--social media or Intertek--and that your decisions somehow need to be made on technical merits. You say you 'prefer to rely', which to me means 'choose to believe'--a silly concept IMO, but we'll go with it. I opt to rely on a the technical merit and integrity of companies that have provided excellent products that have served me and others reliably, sometimes under very tough conditions, for decades.
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The short circuit current waveform will not be even remotely close to correct,
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Where did you get the idea that they have the same energy levels?
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Your opinion is that the waveforms I use to test the meters are adequate to test mains devices. My opinion is that you're ignorant on AC mains testing. Of course, you could start doing some research if it interests you and correct that deficiency but you will not find many details in this thread about it.
Thanks for the more detailed explanation, but if I am not completely wrong, we might talk about two different thing.
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And if the rise time is the same, the peak voltage is the same and the energy as well, than the short circuit current waveform during that small spike can not be that different.
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Where did you get the idea that they have the same energy levels?thinking I may be able to explain where your thinking is flawed but you refused to answer. Ignorance can be overcome easily with education but I suspect learning is also a problem for you. It's similar to discussing the basics with the people interested in perpetual motion. It becomes a religion to them and they can't move beyond it.
That's called "reputation" and if you "choose to believe" in the reputation of any particular company, that's your subjective choice, based on a) your personal anecdotal experience, b) the anecdotal experience of others and c) a carefully constructed brand image. I prefer to rely on independent testing and certification reports which despite all their flaws, are an objective criteria.
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The short circuit current waveform will not be even remotely close to correct,
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Where did you get the idea that they have the same energy levels?
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Your opinion is that the waveforms I use to test the meters are adequate to test mains devices. My opinion is that you're ignorant on AC mains testing. Of course, you could start doing some research if it interests you and correct that deficiency but you will not find many details in this thread about it.
Thanks for the more detailed explanation, but if I am not completely wrong, we might talk about two different thing.
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And if the rise time is the same, the peak voltage is the same and the energy as well, than the short circuit current waveform during that small spike can not be that different.
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While I could continue to explain to you that the energy is not the same, you would ignore it. I askedQuoteWhere did you get the idea that they have the same energy levels?thinking I may be able to explain where your thinking is flawed but you refused to answer. Ignorance can be overcome easily with education but I suspect learning is also a problem for you. It's similar to discussing the basics with the people interested in perpetual motion. It becomes a religion to them and they can't move beyond it.
I understand that it is not exacly the same setup,but it is similar, by means of trying to clamp down an overvoltage to save a microcontroller, and other sensitive stuff.
Even small energy spikes get through the main lines which damage equipment.
And it is indeed interesting, what different surge protectors can let through from even these small energy spikes.
So if you mean it is ignorance because the small energy involved, than again, you don't necessary have huge surges on the AC line.
I did not ignore your question, but the starting assumption of the discussion was this, and I supposed you read it:
I understand that it is not exacly the same setup,but it is similar, by means of trying to clamp down an overvoltage to save a microcontroller, and other sensitive stuff.
Even small energy spikes get through the main lines which damage equipment.
And it is indeed interesting, what different surge protectors can let through from even these small energy spikes.
So if you mean it is ignorance because the small energy involved, than again, you don't necessary have huge surges on the AC line.
You did not argue with this statement. That is why I asked you what else can be so dramatically different if we are talking about LOW ENERGY SURGES. But than you got back to the energy level.
If I commented this in your style would that raise the quality level of the discussion?
It can be hard for a company to change that image. I can remember when Brymen had a reputation as a chinky Taiwanese maker of cheap meters, it took several decades to get to where they are now.
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But then you have companies like Uni-T that have a reputation for changing and omitting parts in models on a whim.
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I prefer to rely on independent testing and certification reports which despite all their flaws, are an objective criteria.
A review of any testing equipment that emphasizes subjective criteria is, in my opinion, a poor review - and that's what you mostly find on YouTube and social media in general.
You seem to have such contempt for anything made in China that you wrote off the UNI-T UT125C right off the bat, even though I have linked to its certification by Intertek. Then you dismissed the Intertek Shenzhen "branch"
I guess there is no end to your arrogance.
That's anecdotal, and even though it matters for a company's reputation or "vibes", objectively you would have to comparatively test to see how it affects the product's performance or safety.
But what I was talking about (and maybe bdunham7 also) is just the voltage spike itself without mains connected. And if the rise time is the same, the peak voltage is the same and the energy as well, than the short circuit current waveform during that small spike can not be that different.
There are already standards for this, so if you were going to rig something up, I'd start there.
A few years back, someone was selling off a pallet of test equipment for AC line testing. Looked like a lab had closed and they were selling off the assets. If I were going to toe dip into this area, I would try and find another deal like this.
Hire a good looking female to narrate it for you and you will have a million followers in no time.A few years back, someone was selling off a pallet of test equipment for AC line testing. Looked like a lab had closed and they were selling off the assets. If I were going to toe dip into this area, I would try and find another deal like this.
If I wanted a YouTube channel to compete with ElectroBOOM, that would be the way to go! Buy cheap crap on Amazon and blow it up, all with big, official looking equipment.
Just a note: the UNI-T UT61E+ that Joe is testing these days is not independently certified. On the other hand, the UT161E, which externally seems identical, is certified by Intertek (from the manual: "Conforms to UL STD 61010-1, 61010-030, 61010-2-033, Certified to CSA STD C22.2 No. 61010-1, 61010-030, 61010-2-033.")
The cost of these two DMMs, including VAT and shipping to France:
- UT61E+: 73€ shipped from China (2 to 3 weeks).
- UT161E: 75€ shipped from Spain (3 to 7 days).
Personally I would rather pay an extra €2 and get the certified UT161E.
But what I was talking about (and maybe bdunham7 also) is just the voltage spike itself without mains connected. And if the rise time is the same, the peak voltage is the same and the energy as well, than the short circuit current waveform during that small spike can not be that different.
Just to be clear, what I was referring to would be something completely different, and a diagnostic or analytical tool not a test. I don't have the time or inclination to pursue it at the moment, so I'll just point out that the whole situation with spikes and energy isn't that simple. For example, it is entirely possible for a surge to 'get through' and damage a microprocessor without ever causing any arcing or even clamping in a protective circuit, so damage to equipment is not perfectly correlated to potential for arc or fire hazards. There are already standards for this, so if you were going to rig something up, I'd start there. One issue that you'd have to consider is that an AC mains connected device is in a low-impedance circuit and you can't really have low energy, low impedance and high voltage--so something has to give.
A few years back, someone was selling off a pallet of test equipment for AC line testing. Looked like a lab had closed and they were selling off the assets. If I were going to toe dip into this area, I would try and find another deal like this.
If I wanted a YouTube channel to compete with ElectroBOOM, that would be the way to go! Buy cheap crap on Amazon and blow it up, all with big, official looking equipment.
Especialy the low energy spikes will be hard to find any info about, because they don't cause imediate failure so it would be difficult to asess what would be the most common but already harmful energy and voltage level.But I think something well within Joes generators range.
[...] One could look at the input current to a multimeter during an ohms-function overload, to see the PTC heat up and settle. [...]I meant long-term overload, such as mains applied when on the ohms function. PTC holding current might be 10mA? hard to tell temperature in the heatshrink tubing sleeve but it's going be hot.
....generally multimeters have a separate 10MOhm voltage input and a 10kOhm+PTC resistance/continuity input.
Keep those stories coming. We're here all night folks.
Especialy the low energy spikes will be hard to find any info about, because they don't cause imediate failure so it would be difficult to asess what would be the most common but already harmful energy and voltage level.But I think something well within Joes generators range.
You're going to have to define and quantify 'low energy' and fully specify the circuit characteristics and other test conditions for any further discussion to have meaning. I wouldn't call the jqsTM transients 'low energy'.
Here's two of them side by side:
....generally multimeters have a separate 10MOhm voltage input and a 10kOhm+PTC resistance/continuity input.
Keep those stories coming. We're here all night folks.
I found another meter that has a separate path for voltage that doesn't go via the surge resistor/PTC.
It's none other than our little friend the Fluke 101!
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The voltage input goes through R2/R3/R4/R5/R6/R7/R8. The Ohms/diode/continuity/etc. goes the other way.
See, I'm not crazy! :) :) :)
I haven't looked closely at this particular Uni-T but generally multimeters have a separate 10MOhm voltage input and a 10kOhm+PTC resistance/continuity input.
Here's two of them side by side:
So you have your choice of a CAT III/1000V meter with 600V fuses and quite a population of PTCs and MOVs or a CAT III/1000V meter with even less appropriate fuses and no MOVs. Let's call the versions 'fail' and 'didn't even try'.
....generally multimeters have a separate 10MOhm voltage input and a 10kOhm+PTC resistance/continuity input.
Keep those stories coming. We're here all night folks.
I found another meter that has a separate path for voltage that doesn't go via the surge resistor/PTC.
It's none other than our little friend the Fluke 101!
(https://www.eevblog.com/forum/testgear/fluke-101-multimeter-teardown/?action=dlattach;attach=77867;image)
The voltage input goes through R2/R3/R4/R5/R6/R7/R8. The Ohms/diode/continuity/etc. goes the other way.
See, I'm not crazy! :) :) :)
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But then you have companies like Uni-T that have a reputation for changing and omitting parts in models on a whim.
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That's anecdotal, and even though it matters for a company's reputation or "vibes", objectively you would have to comparatively test to see how it affects the product's performance or safety.
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The surge resistor and PTC are still used in the voltage range to clamp via the two series MOVs to ground.
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The PTCs aren't on the "voltage measurement" part of a multimeter circuit, they're on the much lower-impedance "ohms/continuity/etc" part of the circuit.
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But then you have companies like Uni-T that have a reputation for changing and omitting parts in models on a whim.
...
That's anecdotal, and even though it matters for a company's reputation or "vibes", objectively you would have to comparatively test to see how it affects the product's performance or safety.
Fungus posted this before, two UT-61E's.
I don't need a compartive test to tell me that one lacks all the MOV's and has smaller and lower rated fuses than the other.
EDIT: Here is my UT61E added to the right side:
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=1284730;image)
And there are other examples of Uni-T meters doing this. I've even had it myself were a meter I have differs a lot from one someone else has.
(WTB I have not been following any argument in this thread, so I don't know the history here)
The surge resistor and PTC are still used in the voltage range to clamp via the two series MOVs to ground.
Once you have a clamp like for any main energy spike, then you don't need any major protection on the voltage input because of the attenuator. Maybe just a basic extra transistor clamp or something just in case.
EDIT: Here is my UT61E added to the right side:
The 10MOhms in that path will obviously attenuate a spike to the point where it can't damage the IC or it can be clamped by small components.
EDIT: Here is my UT61E added to the right side:That's three non-anecdotal variants!
Worse: You can see Uni-T deliberately planned to produce these unsafe variants after CAT certification by Intertek - the PCB has holes in it for different size fuse holders.
The surge resistor and PTC are still used in the voltage range to clamp via the two series MOVs to ground.No argument.
A few pages back I said something about the volts-measurement path inside meters not going via the surge resistor+PTC and I got called out for it. The 101 is an example of a well regarded meter that does exactly that. :)
The Fluke 28 is another example.
The Fluke 28 is another example. The 10M input resisotr is a ceramic jobbie, but in this case it does have an extra MOV on the other side of it.
The surge resistor and PTC are still used in the voltage range to clamp via the two series MOVs to ground.No argument.
What if the PTC heats up? Now the MOVs aren't doing much.
My only point was that many meters have a path from the input jack to the IC that doesn't go via the PTC as shown in your input protection video.
The PTCs aren't on the "voltage measurement" part of a multimeter circuit, they're on the much lower-impedance "ohms/continuity/etc" part of the circuit.
I haven't looked closely at this particular Uni-T but generally multimeters have a separate 10MOhm voltage input and a 10kOhm+PTC resistance/continuity input.
Which "UT61E" do you claim is certified? Which one do you think you'll get for 75 Euros? Better cross your fingers when you order...
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A) You removed the PTC and found the 101 could no longer read AC and/or DC voltages?
B) You removed the PTC and found the 101 could still read AC and/or DC voltages but you don't want me to eat too much crow?
C) You want to continue to believe your original statements and are concerned they are wrong?
D) Lack the soldering skills to lift one pin or the 101 costs too much and you are concerned about damaging it?
E) You're too lazy and can't be bothered to test your theory?
...
A) You removed the PTC and found the 101 could no longer read AC and/or DC voltages?
B) You removed the PTC and found the 101 could still read AC and/or DC voltages but you don't want me to eat too much crow?
C) You want to continue to believe your original statements and are concerned they are wrong?
D) Lack the soldering skills to lift one pin or the 101 costs too much and you are concerned about damaging it?
E) You're too lazy and can't be bothered to test your theory?
Joe, you are assuming Fungus actually owns or has access to a Fluke 101. It's not that he is too lazy to test his theories, it's just that he can't. He really is the perfect armchair expert on DMMs that he has never even seen in person, much less taken apart.
How many Fluke meters do you own? 3 or so as I recall?
Five! (101, 187, 27FM, 37, 8060A)
Brymens? Only one! :)
The UT61E has been discontinued, so your entire argument is moot.In France, does the word discontinued mean something is no longer available for purchase? Or are you just trolling him?
In fairness, the two meters to the right were never subjected to testing as AndrewBCN pointed out. Also, Dave was an earlier production model....
But then you have companies like Uni-T that have a reputation for changing and omitting parts in models on a whim.
...
That's anecdotal, and even though it matters for a company's reputation or "vibes", objectively you would have to comparatively test to see how it affects the product's performance or safety.
Fungus posted this before, two UT-61E's.
I don't need a compartive test to tell me that one lacks all the MOV's and has smaller and lower rated fuses than the other.
EDIT: Here is my UT61E added to the right side:
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=1284730;image)
And there are other examples of Uni-T meters doing this. I've even had it myself were a meter I have differs a lot from one someone else has.
The discussion evolves around safety and certifications. I don't know what the pass/fail criteria is for safety, only what I was told from two different companies that had very different interpretations. I assume all three flavors have been certified for use in CAT III 600 or what ever they are marked for. Is the cert worth anything? Personally, I have bad vibes about the whole process. :-DD
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But then you have companies like Uni-T that have a reputation for changing and omitting parts in models on a whim.
...
That's anecdotal, and even though it matters for a company's reputation or "vibes", objectively you would have to comparatively test to see how it affects the product's performance or safety.
Fungus posted this before, two UT-61E's.
I don't need a compartive test to tell me that one lacks all the MOV's and has smaller and lower rated fuses than the other.
EDIT: Here is my UT61E added to the right side:
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And there are other examples of Uni-T meters doing this. I've even had it myself were a meter I have differs a lot from one someone else has.
[...In France, discontinued means exactly the same as in any part of the US or the UK:
Referring to your recent comment:QuoteThe UT61E has been discontinued, so your entire argument is moot.In France, does the word discontinued mean something is no longer available for purchase? Or are you just trolling him?
The UT61E has been discontinued, so your entire argument is moot.
Oh, and just a note: as usual, you post pictures from others without attribution or mention of their origin. That picture of two different UT61E DMMs is by user Nisei and comes from this thread:
Joe, you are assuming Fungus actually owns or has access to a Fluke 101. He really is the perfect armchair expert on DMMs that he has never even seen in person, much less taken apart.
I am not sure what your point is exactly. UNI-T is certainly not the only manufacturer that changes the PCB of a product during its lifecycle, or that populates the PCB with different components from one production batch to another.
referring to 3~4 years old pictures of a different, discontinued model seems to me a bit irrelevant and a distraction.
[...In France, discontinued means exactly the same as in any part of the US or the UK:
Referring to your recent comment:QuoteThe UT61E has been discontinued, so your entire argument is moot.In France, does the word discontinued mean something is no longer available for purchase? Or are you just trolling him?
discontinued
adjective
(of a product) no longer available or produced.
In any case, why bring a discontinued product with various versions into the discussion, when my comment was about the UT61E+ and its Intertek-certified version the UT161E and the negligible price difference between these two?
In any case, why bring a discontinued product with various versions into the discussion, when my comment was about the UT61E+ and its Intertek-certified version the UT161E and the negligible price difference between these two?
I found another meter that has a separate path for voltage that doesn't go via the surge resistor/PTC.
See, I'm not crazy! :) :) :)
Have a look at the input diagram that I posted in response to Dave, then note that the 7 resistors you are referring to are 143K, so they add up to 1M. Without tracing it out or finding a schematic I can't be 100% sure of the configuration, but the 87V/AN schematic I posted is fairly typical for contemporary Fluke designs. As for others, it will be driven by the requirements of the chipset that they use.
A) You removed the PTC and found the 101 could no longer read AC and/or DC voltages?
B) You removed the PTC and found the 101 could still read AC and/or DC voltages but you don't want me to eat too much crow?
C) You want to continue to believe your original statements and are concerned they are wrong? (burying your head in the sand rather than confronting it)
D) You lack the soldering skills to lift one pin or the 101 costs too much and you are concerned about damaging it?
E) You're too lazy and can't be bothered to test your theory?
F) I've burned myself too many times trying to solder and am scared to pick that thing up!!
Burning yourself with a soldering iron is nothing to be ashamed of. :-DD
Crazy, no, but you may have jumped to a conclusion a bit early.
Have a look at the input diagram that I posted in response to Dave, then note that the 7 resistors you are referring to are 143K, so they add up to 1M.
Maybe that path is something to do with the IEC61010 requirement for the meter to still show hazardous voltages even if it's damaged. It could go directly to a comparator and show an indicator on screen or something like that. It would work in all ranges with no CPU required.
Right now I'm trying to think what it would be for if it's not for voltage measurement.
OK, I wasn't paying attention here but I've got other meters with a resistor chain like that and they add up to 10M. I've measured it.
[...] UNI-T is certainly not the only manufacturer that changes the PCB of a product during its lifecycle, or that populates the PCB with different components from one production batch to another.
While the manufacturer may have discontinued the product, it's certainly still available for purchase. People can still choose it over other products.
How is that relevant to the UT61E+ and its Intertek-certified version the UT161E?
G) You're in gloat mode and sound fairly sure of yourself so I'm guessing I'm wrong.
I don't mind being wrong, it's an excellent way to learn. I wish I could be wrong more often.
Right now I'm trying to think what it would be for if it's not for voltage measurement.
While the manufacturer may have discontinued the product, it's certainly still available for purchase. People can still choose it over other products.
I never wrote that it was not available for purchase, I wrote that it was discontinued.
Uni-T is doing the PCB copy'n'paste between UT61E+ and UT161E. I see the larger fuses and PTC's, PTC's moved slightly but nothing significant.
Looks like they want to charge a premium for a real 61010 product. I'll bet the BBQ lighter still makes it crash lol.
[...] UNI-T is certainly not the only manufacturer that changes the PCB of a product during its lifecycle, or that populates the PCB with different components from one production batch to another.
UT61E there are least 15 PC board revisions! Did you end up with the kindergarten or junior-high version? Earlier ones were extra junky and ended up in landfill.
It's a bit ridiculous and I don't get a sense they know what they are doing. Seem to sell prototype builds off with fake regulatory claims and as they learn, for years.
And it's over $0.25 worth of parts savings for the boss's new Lambo :-DD
The two schematics one has MOV's, they don't use Rev. #'s and SG4 (4th MOV) at the current-shunts, appears useless.
Rev. 13(GS) has 4 MOV's, 3 PTC's, 600V fuses, rating Cat. III 300V, Cat. II 600V
Rev. 12 has 4 MOV's, 3 PTC's, 600V fuses, rating Cat. III 300V, Cat. II 600V
Rev. 9C no MOV's, 3 PTC's, 250V fuses, rating Cat. III 1,000V, Cat. IV 600V; SOT89 clamps
Rev. 9A no MOV's, 2 PTC's, 250V fuses, rating Cat. III 1,000V, Cat. IV 600V
Rev. 8 no MOV's, 2 PTC's, 250V fuses, rating Cat. III 1,000V, Cat. IV 600V; SOT23 clamps
UT61E+
Rev. 3 has 3 MOV's, 4 PTC's, 250V fuses, rating Cat. III 1,000V, Cat. IV 600V
Rev. 2 looks the same, blue pcb
Also the pictures of the discontinued UT61E that Fungus posted are from another EEVblog forum member Nisei, who duly noted (as can be seen on the PCB silk screen) that the two UT61E DMMs that he owns are different variants of the UT61E - the model on the left is a UT61E-GS and indeed it has better input protection and larger fuses.
Show me a photo of a Uni-T meter, a manual, or a website link that actually has a meter labelled "UT61E-GS".
I often ask why people continue to discuss safety in a thread that has nothing to do with it.
Show me a photo of a Uni-T meter, a manual, or a website link that actually has a meter labelled "UT61E-GS".
My reply #4203 has them. The meter is still labelled UT61E, but has the "GS" mark and has different CAT ratings.
That's my point. The model number is exactly the same, yet the meter differs greatly in it's safety specs.
That's my point. The model number is exactly the same, yet the meter differs greatly in it's safety specs.Yes, I suppose that's true if the '-GS' is just an internal designation and the model that it was marketed as is just UT61E. So under the jurisdiction of the TUV, they sold one 'UT61E' with protection and lowered CAT ratings, elsewhere they depopulated the protection and increased the purported CAT ratings. I think other companies in other areas may do similar things between markets, but CAT ratings are a globally harmonized standard (or so I thought) so it does seem quite slippery of them.
With my Brymen meters that I resell under the EEVblog branding I have to have them the exact same model number BM235/BM786 and the Brymen name, otherwise if I change it they would of had to have got it entirely UL certified again which is of course lengthy and expensive process. I can't just whack another model number on it and use the UL logo and certificate for physically the exact same meter, it's that strict.
Especialy the low energy spikes will be hard to find any info about, because they don't cause imediate failure so it would be difficult to asess what would be the most common but already harmful energy and voltage level.But I think something well within Joes generators range.
You're going to have to define and quantify 'low energy' and fully specify the circuit characteristics and other test conditions for any further discussion to have meaning. I wouldn't call the jqsTM transients 'low energy'.
The 20J may be overkill but all you safety experts posting here already know where that number came from.
You may not agree but hopefully you at least now have some understanding why I will continue to call my transients low energy.
Is it because that is about the energy used in a defibrillator or because it matches up with the output of an electric fence charger (a powerful one)? :-DD20J is a baby fence unit these days now energisers of 60J are available:
They were indeed idiots when doing this to the UT61E but, in all fairness, that is exactly what they are doing now with their new UT61E+ / UT161E differentiation. Perhaps an attempt to redeem themselves? Even still, this does not excuse slapping false ratings in several of their meters.Show me a photo of a Uni-T meter, a manual, or a website link that actually has a meter labelled "UT61E-GS".
My reply #4203 has them. The meter is still labelled UT61E, but has the "GS" mark and has different CAT ratings.
That's my point. The model number is exactly the same, yet the meter differs greatly in it's safety specs and ratings.
Why would anyone trust a company that sells the exact same model number meter in different markets with different safety/protection components?
At the very least give it another model number.
With that in mind, given the mayhem your jqs IEC LiteTM transients cause, it is difficult for me to see how some of these units could emerge from the full mains-connected IEC transient test unscathed, unless the criteria being applied are just that the device not explode or trip the mains limiting.In my interpretation of the 61010 is that the meter is not expected to survive the transients. The fact Fluke and others are not screaming at the top of their lungs about this is an indication I am not alone in my interpretation. Sure, Fluke has some spectacular videos of exploding meters, but they talk about containing the energy of the damage inside the housing to avoid high speed ejection of material and quenching arc flash.
Uni-T is doing the PCB copy'n'paste between UT61E+ and UT161E. I see the larger fuses and PTC's, PTC's moved slightly but nothing significant.You can bet whatever you want, but thanks for digging out a picture of the internals of the UT61E+ and the externally identical, but internally quite different, intertek-certified UT161E (from a Russian forum?).
Looks like they want to charge a premium for a real 61010 product. I'll bet the BBQ lighter still makes it crash lol.
Show me a photo of a Uni-T meter, a manual, or a website link that actually has a meter labelled "UT61E-GS".
My reply #4203 has them. The meter is still labelled UT61E, but has the "GS" mark and has different CAT ratings.
That's my point. The model number is exactly the same, yet the meter differs greatly in it's safety specs and ratings.
Why would anyone trust a company that sells the exact same model number meter in different markets with different safety/protection components?
At the very least give it another model number.
So UNI-T charge a 3€ "premium" for the larger fuses and PTCs, and proper independent testing and certification for the UT161E, which as you well know, has a cost.
It still has the stupid transistor tester though. I'd never own one because of that "feature". I'd have to do a facepalm every time I turned the selector past that position on the dial.
I often ask why people continue to discuss safety in a thread that has nothing to do with it.
One would need to reread the entire thread to see how that seeped in, but I suspect the similarities of your test transient levels to the ones specified for the CAT ratings are one factor.
Anyhow, by now I agree with you, if you are referring to safety as meters exploding or arc-flash type concerns. My concerns are similar to what you have said about wanting meters to not die during normal, non-dangerous bench or other use. Transients are one way to kill them of course, but accidental overvoltage is another. I had one set of expectations about what a CAT-rating would mean about this, specifically that a meter with a CAT rating for any voltage--like a bench meter rated CAT I/1000V--would endure 1000VAC or 1000VDC on any range or input selection without damage. There's also the expectation that after the transient tests, the meter works. If those expectations on my part are wrong and the CAT ratings don't indicate performance in that regard across the board, or if different manufacturers have different standards regarding these issues, then the CAT ratings themselves are meaningless to me and of questionable value to anyone else, IMO.
If anyone wants to comment on my assertion that a CAT x/1000V meter should withstand a full 1000V on any input setting or jack, I can see about setting up a test.
Some of the smaller PTCs are only rated for 500V. Some meters have only a single PTC which if the low voltage clamp is active, will have well over 900V across them.... Maybe.... Turn the dial, I suspect you will get a light show.
Well that doesn't sound very robust! I don't know if that is a failure to meet a standard or not, but it seems like a basic expectation to me. Every CAT labelled meter I currently have that isn't known junk should pass that test. Some of them already have by accident.
Maybe start reading here. Dave chimes in. So do I.
https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg1580530/#msg1580530 (https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg1580530/#msg1580530)
Is it because that is about the energy used in a defibrillator or because it matches up with the output of an electric fence charger (a powerful one)? :-DD20J is a baby fence unit these days now energisers of 60J are available:
https://pel.co.nz/en-nz/node/11974
I earlier wrote that for the extra 3€, I would rather buy the Intertek-certified UT161E rather than the UT61E+ that Joe is testing these days. The picture you posted just confirmed this.
Hell no !Is it because that is about the energy used in a defibrillator or because it matches up with the output of an electric fence charger (a powerful one)? :-DD20J is a baby fence unit these days now energisers of 60J are available:
https://pel.co.nz/en-nz/node/11974
Don't take a whiz on that!
Here's a genuine CAT III 300V certified meter which has been discussed somewhere in the middle thread. It has two resistor trails leading off before anything gets to the PTC. The R31/R30/R29/R28 chain is 10MOhms, the same as the impedance of the meter in volts mode. It's not the only meter I own that's like this, hence the silly ideas in my head.
I think the input circuit is clear enough in this photo:
...
I lifted up one leg of the PTC as joe suggested:
...
Guess what? It still measures volts perfectly!
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OK, maybe the Fluke 101 doesn't work that way (I should have looked at the resistor values before opening my mouth) but there's definitely some certifiable meters that do work that way.
I suspect you have been looking at too many low end meters like the UNI-T, ANENG.... Your statement about "...generally multimeters have a separate 10MOhm voltage input.." could be correct as I suspect there are more low end meters being introduced and sold. We love our cheap, disposable products which drives the market and I just don't want to admit it.Keep those stories coming. We're here all night folks.
I'm having a moment, aren't I?
I am all for YOU running a test like this. I think if you want to light it up, you are going to have to use the meter incorrectly and turn the function switch with it live. If you pick a meter that I have already and find it survives, maybe I can attempt to repeat it. I have that one 121GW that was used for the majority of my destructive tests. It has been certified. I could toss that into the mix as well.
1kVDC with more than enough current to cause a major meltdown ready when you are.
Just another cheap meter. These don't surprise me but I'm interested in what your Fluke 101 does.
Just another cheap meter. These don't surprise me but I'm interested in what your Fluke 101 does...
I'm more interested in the function of that circuit than simply confirming something that's already known - science doesn't advance that way. Corrrect procedure requires a theory before I barge in and do any experiments so I need to find time to sit down and trace out the 101 PCB as the next step.
PS: The Fluke 101 is a "cheap meter". For the price of a Uni-T U61E I can get a Fluke 101 and an Aneng 870.
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I don't want to abuse the meters by switching ranges under power, just test them at max voltage on all ranges. I'll leave exploding things to others for now.
First test was a Fluke 116. You have tested a 115, I don't know if you have it still or how similar they are. I gave it 600VDC and 600VAC/100Hz in all ranges, 10-15 seconds per range, then checked its calibration afterwards. All good. I did notice that when it clamps, it can clamp a lot more current than my calibrator can supply. I had to use a different DC supply. For AC, I had to start at a lower voltage then work my way up as fast as I could push the buttons.
The next victim was actually not a handheld, but an old Fluke 8842A bench meter. No CAT rating, but it took the 1000VDC and 700VAC listed on the front panel without complaint, ohms range and all, but the calibrator started whining (literally) so I quit for the night. I'm really not looking to blow that one up.
I can toast a Harbor Freight meter for giggles, but other than that I don't have a lot to throw at it right now.
Now I need a new theory. The signal isn't used on either of the main voltage ranges and it's not for the hazardous voltage indicator. ???
The resistor chain goes up to the selector and is connected across to the adjacent track when the switch is in the mV/Ohms/Capacitance/Hz modes.
When cold, I am expecting with a kV applied, the initial draw is somewhere around 1kV/2000ohms or 500mA. Higher for some of the cheap meters. I doubt many electronics hobbyist have that sort of power supply on hand. I would think the use case was you touch the leads to the live source with the meter set to each function, except for the current. Allowing a minute or so for the PTC to cool between tests. Creeping up on the voltage would seem like a rare case.
As for range switching, I think they do put some thought into that. For example, the Auto Lo-Z function requires you to cross the OFF position to get in or out of it.That off position could be the end of the meter. You had the meter in the lowZ, attached to a high current DC kV source, then turn it to the OFF position. I doubt that will end well.
The concern would be engaging a low voltage clamp and opening the contact with a kV DC applied. I don't see too many meters surviving that but I've never tried it.
For AC, thing could get interesting if you are suggesting that any frequency is open game. We just need to stay below the printed voltage on the meter. I cooked that UT61E+ doing just that and suspect that may of these cheap meters that only use a PTC to limit the current would be damaged well below their claimed level. I'm not sure how that fits into your criteria.
The concern would be engaging a low voltage clamp and opening the contact with a kV DC applied. I don't see too many meters surviving that but I've never tried it.I think the meter's main defense against that would be that the PTC quickly lowers the current to a level that a switch can maybe handle. If you spin the dial with the power on, you may defeat that feature. I suspect that even if the meter doesn't burn up on the spot, there would be cumulative damage.
Your 116 specs the frequency to 50kHz. Dave's 121GW, 1MHz. Seems like the 121GW should handle 1MHz within the voltage limits. Maybe...
Of course, I would think a meter with a spec'ed freq counter at 220MHz would be able to read 220MHz before the solder starts to reflow and the case melts.
The 20J may be overkill but all you safety experts posting here already know where that number came from.
Hmmm. Is it because that is about the energy used in a defibrillator or because it matches up with the output of an electric fence charger (a powerful one)? :-DDQuoteYou may not agree but hopefully you at least now have some understanding why I will continue to call my transients low energy.
Thanks for the detailed explanation. Low is a relative term, of course, and relative to MOV ratings, IEC transients, etc, 20J is obviously much lower. The comment I responded to was talking about damage to semiconductors, etc and there 20J will pop the lid on quite a few devices. I think the low energy events he was referring to are the sorts of noise, ESD or spikes that might get through normal filtering for reasons other than that they overwhelm the protection systems by simply exceeding their voltage or energy limitations. Piezo igniters and 220MHz RF come to mind....
Silly you for believing anything printed on a UNI-T box..... :-DD Did you ever figure out what the output voltage and power of that RF amp was?
To melt the solder what, 20W - 40W? A bit of damage to the PCB, 80W? Say the meter presents 5 ohms @ 120MHz, 20V would get you 80W. Just a ballparkish guess. Let's say double that. Does 40V seem like a lot to you? I mean, I thought you were all about kVs?! :-DD
There must separate path injecting current into DUT for resistance and capacitance, and this composite 1 MOhm resistor is measurement path for these ranges. There will be transistor clamp after it somewhere before going into DMM chip. ...
Nice job sir. Do you have the tools/skills needed to remove one of the resistors that make up the chain R8-R2?
...I have no plans to do much testing with that old Fluke after saving it from scrap. It's only job is to hang out next to my 8000A and act as a reminder of days of old. :-DD
And your 8506A, despite being a specialized HF AC instrument, is only good for half that. Having a wirewound resistor or a common-mode toroid right at the front end might help in these extreme cases, but I suspect that level of RF will burn up lots of things. If you're doing it some more, I'll watch from here.
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I actually bought a cheapo hot air gun a couple of weeks ago. Maybe this is the opportunity to take it out of the box. :)I've soldered with a heat gun for many years. Your boards may be lead free and require more heat than you can get out of your gun. I would practice with the cheap meter first. Maybe blend in some tin lead on the Fluke to help pull them until you get an idea how to use the new gun. Always new things to learn.
Consider the newer small Fluke multimeter input protection circuit, instead of desoldering things.
You can see the three main channels, the 1MEG, 10MEG and how they are used.
It seems like you are backing down about surviving the max marked voltage on the face of the meter. Rather we need to actually read the manual and understand the specs to save the meter.
Your 116 specs the frequency to 50kHz. Dave's 121GW, 1MHz. Seems like the 121GW should handle 1MHz within the voltage limits. Maybe... Of course, I would think a meter with a spec'ed freq counter at 220MHz would be able to read 220MHz before the solder starts to reflow and the case melts.The concern would be engaging a low voltage clamp and opening the contact with a kV DC applied. I don't see too many meters surviving that but I've never tried it.I think the meter's main defense against that would be that the PTC quickly lowers the current to a level that a switch can maybe handle. If you spin the dial with the power on, you may defeat that feature. I suspect that even if the meter doesn't burn up on the spot, there would be cumulative damage.
Maybe. It would be easy to setup a simple test without a meter and just see if an arc could be drawn. I would use a 1k resistor in series with the PTC, apply the 1kVDC across it, let the PTC heat up, then open the circuit. It's nothing I have ever tried. I'll make a clip of it.
That's the Fluke 15, 17 family. The 101, 107 only uses two MOV's. Point is it's been optimized beyond the classic 87 input protection, and for cost as well.
And here is an important announcment for The Uni-t Ut60e Protection Circuit Variations Collector Society:I only found a UT61D, not UT61E: https://www.clasohlson.com/se/Multimeter-med-USB-UNI-T-UT61D/p/36-4717 (https://www.clasohlson.com/se/Multimeter-med-USB-UNI-T-UT61D/p/36-4717)
(short: TUUPCVCS)
There is a possibly really unique version aviable in Sweden, the Clas Ohlsson edition. Which is a kind of store chain. Being a swedish version I suppose maybe it comes with REAL fuses from the Nobel factories.
(Note for the Fluke test guys: Reinforce the blast shield if testing those!)
Being a rarity and a collectors item soon, I consider sending it to anyone for a symbolic 2000 Euro price. (Shipping included) It would be a solid investmen in these hectic days! (No I don't have it yet, so can't post pictures.)
It was me who requested the test :)Left on for 10 seconds, survives just fine at the nominal 245V here. Readings a smidge low as the PTC recovers.
So I'm curious about why these tests would be conducted at those levels on meters with a CAT-anything label at. Should the meter not withstand, without damage, the application of full rated voltage (1000V in this case) to any input on any setting? AFAIK, even supposedly fragile CAT I bench meters will pass that test. Some older pre-CAT bench meters have separate, lower specifications for voltage protection on ohms and such, but even the old Fluke 8842A will pass that test.
Link to the persons posts who had asked about this may be found here:
https://www.eevblog.com/forum/repair/uni-t-ut61e-diode-mode-repair/ (https://www.eevblog.com/forum/repair/uni-t-ut61e-diode-mode-repair/)
Some of the smaller PTCs are only rated for 500V. Some meters have only a single PTC which if the low voltage clamp is active, will have well over 900V across them.... Maybe.... Turn the dial, I suspect you will get a light show.
***QuoteI'm referring to meters that some claim to be properly rated, not ones where there isn't any dispute that the CAT info printed on them is a bad joke.
Sorry, I missed that part. If a KVDC were applied with unlimited current and the function switch were rotated, I suspect you would burn the contacts on most meters. I wouldn't recommend anyone attempt it.
And here is an important announcment for The Uni-t Ut60e Protection Circuit Variations Collector Society:I only found a UT61D, not UT61E: https://www.clasohlson.com/se/Multimeter-med-USB-UNI-T-UT61D/p/36-4717 (https://www.clasohlson.com/se/Multimeter-med-USB-UNI-T-UT61D/p/36-4717)
(short: TUUPCVCS)
There is a possibly really unique version aviable in Sweden, the Clas Ohlsson edition. Which is a kind of store chain. Being a swedish version I suppose maybe it comes with REAL fuses from the Nobel factories.
(Note for the Fluke test guys: Reinforce the blast shield if testing those!)
Being a rarity and a collectors item soon, I consider sending it to anyone for a symbolic 2000 Euro price. (Shipping included) It would be a solid investmen in these hectic days! (No I don't have it yet, so can't post pictures.)
That said your post is funny.
However it seems to be the bog standard "Chinese" version and not the "GS" branded version because the listed spare fuses for it are 1A 240V for the mA range.
But they are 0.5A 600v in the "GS" version.
And the linked manual on their page also claims the instrument is CAT-IV rated at 600v and CAT-III at 1000v which we all know is blatantly false.
(The GS rated meter is CAT-III 300v and CAT-II 600v but even that is a stretch if you follow the link in my quote below from Joe).
https://www.youtube.com/watch?v=gKK7Dl-fnjk (https://www.youtube.com/watch?v=gKK7Dl-fnjk)From the video: "... I think it would do the meter in." Proceeds to film in slow motion plasma with a 5mm arc from 1000V DC power supply. :popcorn:
From another TÜV 61010 test report, they added tests:
16.2DV.1
"Multifunction meters and similar equipment shall be tested by changing the function /range selector to all possible settings while connected to the maximum rated source."
16.2DV.2
"Compliance is checked by testing to verify no HAZARD occurs when switching selector settings."
Consider the newer small Fluke multimeter input protection circuit, instead of desoldering things.
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Even just a V-Hz number, as if the average user can do math in their head, won't help. I'm pretty sure that almost any meter can take 10mV @ 1GHz, but not many will do well at 1GV @ 10mHz! So yes, that is always going to be an RTFM specification, its just a shame that most manuals omit this entirely, even when the meter has specifications that might invite disaster.
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Even my 8505A would like to stay below 2*107. And your 8506A, despite being a specialized HF AC instrument, is only good for half that. Having a wirewound resistor or a common-mode toroid right at the front end might help in these extreme cases, but I suspect that level of RF will burn up lots of things. If you're doing it some more, I'll watch from here.
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You're firing on all eight cylinders today I see. Still, it was a good opportunity to try out that heat gun.Consider the newer small Fluke multimeter input protection circuit, instead of desoldering things.
I was thinking I could maybe take the spring contact out of the range selector - it breaks the circuit, it's much easier!
Consider the newer small Fluke multimeter input protection circuit, instead of desoldering things.
I was thinking I could maybe take the spring contact out of the range selector - it breaks the circuit, it's much easier!
I would expect that my first Fluke DMM was highly susceptible to being damaged by RF (or looking at it sideways). I suspect as the front ends of these handhelds evolved, the need to derate them was less important. Of course, you still end up with meters like the UNI-T UT61E+ having some sort of frequency counter speced at 220MHz with a couple of PTCs in series, but I suspect most modern robust meters would not have a problem. Like I had shown with the BM78x, with the same setup that damaged the UT61e+, the PTCs had very little heat. As I demonstrated, that resistor was fairly stable to 50MHz and a 1kohm just doesn't present much of a load to the small amplifier.
I don't mind running other tests if you had something in mind. I could take that same resistor/PTC we just used and run them any way you like. The same with that Brymen BM78x prototype. Let me know.
I have 3 of the 8000A models in my junkpile, they're all toasted and they all have evidence that they've been soldered on during their lifetimes. But those were early days in the whole field, not just for Fluke. Meters may be more durable nowadays, but they still have limits and I, for one, would like to see those limits specified in detail--but they usually aren't.I wouldn't have spent any time rebuilding my 8000A had it not been my first DMM. Beyond it's sentimental value and being the catalyst for running these tests, it has no other redeeming qualities.
I haven't see the video of you giving any other meters the jqs MeltCalTM treatment, I'll have to go look. I think it might be interesting to try to determine what parts are used in the meters and then characterize and test those--and look at datasheets if possible--to see who is using what and how the expected component performance matches up with the claimed performance of the meter.
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After the attached comment, I demonstrated the BM78x at over 100MHz during Part 2 of the UT61E+ review. At these higher frequencies, the majority of the voltage drop will be across the resistors, not the PTCs. I'm guessing this would have been obvious to all the radio hobbyist.
You're firing on all eight cylinders today I see. Still, it was a good opportunity to try out that heat gun.
Just don't lose the bugger!
OK, I took out the spring from the selector switch.
Perhaps we need a MacroVNA, with a 1kW output.
For the F27, you could for example, try using the AC line to get the PTCs to switch, then quickly attach it to the calibrator. Maybe just a DPDT switch to prevent it from cooling.
I assume these are all after the PTCs have switched. Otherwise for LowZ, I would expect the current to be much higher. At a kHz, I doubt you will see much change.
QuoteI assume these are all after the PTCs have switched. Otherwise for LowZ, I would expect the current to be much higher. At a kHz, I doubt you will see much change.
Well, there's the problem--it does change, and a lot. I tested them at low and high voltages with different frequencies. I used 6V and 600V for the F116, then 15V and 1000V for the F27. I needed to use the higher voltage on the low end for the F27 because it doesn't have a Lo-Z mode, so I have to overwhelm the low voltage clamps in whatever circuit I'm using (OHMS in this case) so that I see mostly the PTC/resistor characteristics.
At 6VAC in 'AUTO V/Lo-Z', the F116 had a current of about 2.0mA @ 50Hz, and that didn't change much at 1kHz or even 10kHz. However, at 600VAC, it had about 1.9mA at 50Hz, but that rose to 5.1mA @ 1kHz.
The F27 at 15VAC stayed in the 2.1-2.3 range, not totally steady because the OHMs circuit was reacting a bit. At 1000VAC, it showed about 2.0mA @ 50Hz, but raising the frequency to 1kHz caused a surge to about 7mA and then it settled back down to 5.4mA.
Those are huge differences from 50Hz to 1kHz, but only at higher voltages. I have to wonder if the trend would continue if you kept going--the calibrator is maxed out.
I'm only at 106 V-Hz but some of these meters are supposedly good for 10X or 20X more. The next time I place an order maybe I'll get a few of those big dark grey monster PTCs that you find in the larger CAT III/1000 Flukes and try to characterize them. It looks like they pick up 500-1000pF when they warm up. Maybe they should be called thermisto-varactors.
"Not much change" meaning Amps vs mA. At these low frequencies, Xc is not going to be a problem. As you move up in frequency, Xc will dominate and we can damage the parts with a very low voltage, unless there is something else to limit the current. Perhaps a resistor...
"Not much change" meaning Amps vs mA. At these low frequencies, Xc is not going to be a problem. As you move up in frequency, Xc will dominate and we can damage the parts with a very low voltage, unless there is something else to limit the current. Perhaps a resistor...
Yes, the resistor is key at low voltage and much higher frequencies. But take the case of the F116 running at 600V and continuing to ramp up the frequencies. If you just assume that the PTC goes to a state of very high resistance but a capacitance of 0.5nF, the current will go high enough (~70mA) to exceed the rated power of the resistor (which I'm presuming is 5W for now) at around 40kHz. So unless there is some other change, by 100kHz it has likely unsoldered itself if the PTC hasn't come undone first. This is probably a bit of a far-fetched example, but perhaps not when it comes to VFD drives and such. In any case, what caught my eye was the reactance change at higher voltages that wasn't there at lower ones.
So use of the PTC thermistor in the AF and RF ranges is not possible, meaning that applications are restricted to DC and line frequency operation.
Section 6.2 Figure 7 provides some insight.
https://www.tdk-electronics.tdk.com/download/408374/d78540dfe0589d2bd90cabef477c90b9/pdf-general-technical-information.pdf (https://www.tdk-electronics.tdk.com/download/408374/d78540dfe0589d2bd90cabef477c90b9/pdf-general-technical-information.pdf)
Where is the 500pF coming from?
Keep in mind, using your 500nF, 40kHz, 1k resistor that the power dissipation for the PTC is 36 Watts.
In part 4, the UT61E+ is temperature cycled, dropped and transient tested. I also use the NanoVNA to compare the 61E+'s input impedance with a few other meters.
Now these are some classic comments! There's just so many good points but that last sentence of Capture5 is priceless. I never knew I was a 121GW fanboy! :-DD :-DD :-DDMan, those are precious! He clearly did not watch the video.
In part 4, the UT61E+ is temperature cycled, dropped and transient tested. I also use the NanoVNA to compare the 61E+'s input impedance with a few other meters.
it survived the low voltage zapper?
You know what that means, joe? You're going to have to buy another UT61E+ so you can repeat the tests on an "unmodified" one. :-DD
...That was the first comment I saw from them. Painfully lost. I was going to provide them a few links but after reading the second post, knew they are already an expert and would never read them.
Also... parts operating from 0~50C?!? Perhaps in Shenzhen's specials.
Keep in mind, using your 500nF, 40kHz, 1k resistor that the power dissipation for the PTC is 36 Watts.
Well, they did unsolder themselves in your case! But we don't know the power dissipation because we don't know what the phase angle between I and V across the PTC is. The resistor can't escape the heat so easily. This is one of the things I'd like to test on part samples, rather than cooking a nice meter.
Yes, the resistor is key at low voltage and much higher frequencies.
Sounding like a Keysight.But we were told by the one reviewer, they put 10s of thousands of cycles on the same Keysight meter every year. Their rebuttal video on the Keysight where they couldn't even bother to show the
What a difference a day makes. It has a long way to go...Haha, perfect for a quiet lab, it's so silent now! :-DD
Into day 3 of the life cycle. I wonder if there is anything left of the PCB or contacts.I forgot: you constantly evaluate the staus of the contacts during the ordeal, right?
The UNI-T uses grease on the contacts where the 17B+ was dry. Surely the grease will make the UNI-T outperform the Fluke.
Uni-T did a ripoff of the Fluke rotary switch patent US8946571 (https://patents.google.com/patent/US8946571B2/en) and US8093516 (https://patents.google.com/patent/US8093516B2/en), as far as the detents, teeth and spring... copied. So it should work just as good ;) minus the nickel-plated beryllium copper...
It looks like there are still a few via's on the rings contact path though.
Into day 3 of the life cycle. I wonder if there is anything left of the PCB or contacts.
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Wouldn't it be correct to point out that 50,000 rotary switch endstop-to-endstop cycles correspond to > 20 years of daily normal use for any of us here?
So in summary, the contacts and the PCB traces survived the 50,000 cycles in relatively good shape, the (nylon?) spring lobes were slightly worn out and the two small endstop plastic posts broke off, which you "repaired" in less than 15 minutes.
Wouldn't it be correct to point out that 50,000 rotary switch endstop-to-endstop cycles correspond to > 20 years of daily normal use for any of us here?We talked about this early on. Similar to the transient testing, it evolved. If you watch the very first video where I proposed running this test, I was looking at 2000 cycles and was not monitoring the resistance. Someone posted an ad for a UNI-T meter that was rated for 30,000 cycles on the switch.
b) The meter stopped working right after they snapped off (see contact resistance graphs)
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With the wiper contacts not fully rotating, they and the PCB were not subjected to the same level of testing other meters endured.
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No doubt that when the pins broke it limited the movement of the wiper contact.
Well, the meter survived quite well the torture - thanks for doing this.
A few unknowns, especially due to the dramatic self-healing, but that happened with the other meters as well.
After 50k the status of its contacts and PCB are quite interesting. No way to compare with the 17B+, but still...
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With the wiper contacts not fully rotating, they and the PCB were not subjected to the same level of testing other meters endured.
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No doubt that when the pins broke it limited the movement of the wiper contact.
So, the 50,000 cycles "torture test" is to be considered inconclusive with regards to wear of the PCB and contacts?
And would you say the two small plastic pins/post broke of because your test bed setup was hitting the end stops thousands of times?
Does that correspond to a real use case?How would we know? There is a big difference between the guy taking the meter out of a drawer twice a year to look at some clock batteries and someone working as a professional in an industry were the meter is in constant use.
It seems you concluded in the video that the UT61E+ is "more robust" than the discontinued UT61E, but that's not saying much, is it?Yes, discontinued but still available for purchase brand new. And yes, 61E+ more robust after mods than the stock UT61E. From the factory, I have no idea.
Joe, do you know which are the plastics paired in this meter? (The white spring, and the dark one it rubs on.)
And in the Keysight?
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It's bad design. The physical integrity of the dial depends on two small posts for no good reason - the posts could easily be made much bigger for zero additional cost.
Indeed. The transient test could have swayed you out of the switch test a lot earlier in the process. However, as we stand today, the state of the contacts and PCB held much better than the other single-test brands you did (apart from UEI, of course).Well, the meter survived quite well the torture - thanks for doing this.
For a UNI-T product, overall, I couldn't agree more but not when compared with the better brands I have looked at.
Then again, having the meter modified may have saved it from the total destruction we are use to seeing with this brand. It's not good enough for me to want to invest more time into looking at the brand again. After 13 products, I think we have learned our lesson.
Indeed they didn't open, although the cheapest of the bunch (17B+) was the only one completely unfazed during the test cycle. Also, they are Shift-left the price of an UT61E+ (apart from the Keysight, of course), so there is something to be said about bang per buck (something I also commented on Youtube - didn't read yet your reply there).A few unknowns, especially due to the dramatic self-healing, but that happened with the other meters as well.
Well, let's be clear. If we are talking about the contacts opening up (>1kohm) some meters have self healed. Cycle3 shows the five worse meters I have looked at. All of these went open before 7000 cycles. It's good to see Keysight in the mix with UNI-T and the free HF meter. :-DD
But consider the other five meters in Cycle4. None of these meters ever opened up during the entire duration of the test. Note that even Dave's 121GW with it's cobbled switch and countless contacts hung in there. While Dave's test limited the measurement to 10 ohms, I like being able to see the higher values and trusting the HP bench meter.
Yes, the breakoff was quite unfortunate and we don't know when this happened in the test. If they indeed copied Fluke's patent as mentioned by floobydust above, they skimped on materials or were incompetent in their redesign.After 50k the status of its contacts and PCB are quite interesting. No way to compare with the 17B+, but still...
True but again, the wiper contacts were not locked to the knob. How would the meter have held up had the pins not broke? What if they hadn't spec'ed the frequency counter to 200MHz and the meter still had the original components? Would a small ESE event have damaged it?
However, as we stand today, the state of the contacts and PCB held much better than the other single-test brands you did (apart from UEI, of course).
... as you could well see, youtube videos do not bring enough revenue to justify such adventure.:-DD :-DD
I suspect you understood my statement, but let me clarify anyways: I wasn't closing the case on the meter's quality, but only on the evidence we could gather from the (unfortunately) imprecise test.QuoteHowever, as we stand today, the state of the contacts and PCB held much better than the other single-test brands you did (apart from UEI, of course).
It's similar to how Fungus would comment how a meter that was tested at 1kV and survived but then failed it 20kV with no other data collected between, didn't fail until 20kV. While technically true, it's very miss leading. You are also 100% correct. The switch broke early on in the testing. We've seen the contacts open up and a broken detent spring but we've never seen a design so poor that the contacts fail to turn with the knob. And yes, the PCB and contacts were spared.
Just to clarify, I have never asked to hit like or subscribe... Perhaps if I have done that (and created my videos in a language almost as common as Klingon) I could have made enough to splurge on another U1282A to be tortured. :-DQuote... as you could well see, youtube videos do not bring enough revenue to justify such adventure.:-DD :-DD
I have yet to beg for subscribers or $$$. If we run another UNI-T, I may have to start a go fund me account. Not to cover the cost of the meter or the time to run it but for pain and suffering. :-DD :-DD
I suspect you understood my statement, but let me clarify anyways: I wasn't closing the case on the meter's quality, but only on the evidence we could gather from the (unfortunately) imprecise test.
Well, that and perhaps a way to tickle your nerve and see if you would be swayed to run another UT61E+ (or another meter from them) in the future. Judging by your next statement, I now know you have a price... :-DD
Just to clarify, I have never asked to hit like or subscribe... Perhaps if I have done that (and created my videos in a language almost as common as Klingon) I could have made enough to splurge on another U1282A to be tortured. :-D
It's better to just buy products that meet your needs. This meter isn't something I would use but it could be a very good fit for someone else.
I am not a materials engineer and have no idea what they are using. The Keysight appears to be a glass filled material.Its often marked on the plastic with a few letters, so you don't necessarily have to throw it into a gas chromatograph. Glass fibre in that arrangement, does not seems to be good idea anyway, but it did not got so far to rub off the plastic.
Joe, do you know which are the plastics paired in this meter? (The white spring, and the dark one it rubs on.)
And in the Keysight?
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Like Joe, I am not a material/plastics engineeer, but I believe in the UT61E+ the white spring is nylon, whereas the dark plastic it rubs on is polycarbonate.
https://en.wikipedia.org/wiki/Nylon
https://en.wikipedia.org/wiki/Polycarbonate#Applications
Its often marked on the plastic with a few letters, so you don't necessarily have to throw it into a gas chromatograph. Glass fibre in that arrangement, does not seems to be good idea anyway, but it did not got so far to rub off the plastic.
...I believe POM is too stiff to be used as a plastic "spring" part, but in any case, the only way to be 100% certain about what plastics are used for the various parts in any multimeter or electronic test equipment is to get the information straight from the manufacturer, iow next to impossible (unless there are markings on the case, as you suggested).
The white stuff is usually POM. which stands probably for Polyoxymethylene Of Her Majesty.
I will check the Brymen later on, if it has letters on the parts.
Just wondering if any of the expensive meters are actually using teflon.
Its often marked on the plastic with a few letters, so you don't necessarily have to throw it into a gas chromatograph. Glass fibre in that arrangement, does not seems to be good idea anyway, but it did not got so far to rub off the plastic.
I would imagine that if all four prongs of the Keysight meter's detent spring hadn't fractured, it would have eventually started to cut into the case. But they broke really early on in the cycling.
I would have no reason to plug the leads into the UT210E.
There's not much room on the inside. I would imagine it would do about as well as the other 13 UNI-T products I have looked at.
the protection seems to be reasonable, at least compared with other Uni-t's.
....
Grill starters are cheap and easy to find.
I would have no reason to plug the leads into the UT210E.
There's not much room on the inside. I would imagine it would do about as well as the other 13 UNI-T products I have looked at.
This page has photos of the insides. Everything is very close together and there's still no surge resistor on the input.
https://lygte-info.dk/review/DMMUNI-TUT210E%20UK.html
It only claims CAT III 300V, CAT II 600V which is a very low standard. I guess it might meet those numbers.the protection seems to be reasonable, at least compared with other Uni-t's.
If you're confident in the protection you can do a grill starter test at home. Grill starters are cheap and easy to find.
I would have no reason to plug the leads into the UT210E.
There's not much room on the inside. I would imagine it would do about as well as the other 13 UNI-T products I have looked at.
Joe in one thread you mentioned measuring a welding inverter with it, after which in was only reading OL.
Did you use the clamp to measure the amps? What exactly caused the damage?
Sorry, just noticed this and feel like I have to step in to clarify the picture I've posted (even if it's been ages ago) which is being re-used in this thread.Also the pictures of the discontinued UT61E that Fungus posted are from another EEVblog forum member Nisei, who duly noted (as can be seen on the PCB silk screen) that the two UT61E DMMs that he owns are different variants of the UT61E - the model on the left is a UT61E-GS and indeed it has better input protection and larger fuses.Show me a photo of a Uni-T meter, a manual, or a website link that actually has a meter labelled "UT61E-GS".
I would like to ask the community I have UT181a not long but the battery drains very quick I measure the current when off to 18mA is this normal?
Doesn't a mA seem high?
Sure, the current most likely would get higher but is it really worth pointing out? I had asked them how they measured the current but not being there, I really have no idea outside of the cut wire. I don't know anything about the circuit but it could very well be acting as a constant current sink. They would need to supply more data. Still it's a 7ish volt battery. Even with a 100 ohms, at a mA your talking 100mV of drop. Under a percent error. I would think they would be using an amplified shunt without a fuse but who knows.Doesn't a mA seem high?
Especially when you consider the shunt resistance... take that out of circuit and it's going to be even higher.
Under constant observation the current leakage stabilized at 95μA maybe its the RTC and XTAL that's fine I guess...
Under constant observation the current leakage stabilized at 95μA maybe its the RTC and XTAL that's fine I guess...
As I said, mine will sit for months at a time and not discharge.
At first glance yes. The UT61E (and probably the UT61E+) are finicky with transients but why not put it through its paces? Who knows? Perhaps it could be an additional advantage of the "plus" model...Another option, start with the grill starter, kill it in a few seconds and leave it at that.... Nice short video, right to the point. :-DD :-DD
Correct.
I mean, seriously, what is the point of testing the UT61E for "robustness"? We all know it isn't.
Looking at the data I've collected, of the eight UNI-T products I looked at, half never made it past the ESD, AC line tests. During the EEVBLOG review for the 61E+, Dave focuses on the lack of a surge rated resistor. The UT181A is the same and survived some decent hits after a few small changes. Dave talks about the new ground path. It could help but my guess is it won't.Obviously that the "real" test would be with the "third party plus-certified and mega-accredited and über-listed" UT161E, but that is in another price league...
That meter would fail ESD just like the stripped down version.At any rate, I don't think there is much to be lost, especially after you already beaten to death the UT61E original, with excellent suggestions to increase its robustness.
For you, skim the video for a few seconds and your done. Flip side, it takes fair amount of my time to run the tests and edit the videos. For this meter, assuming the grill starter kills it, maybe six days. Half of that would be cycling the function switch.
(edit) Kerry Wong also did a teardown of the UT61E+
http://www.kerrywong.com/2021/04/04/teardown-of-a-uni-t-ut61e-true-rms-multimeter/ (http://www.kerrywong.com/2021/04/04/teardown-of-a-uni-t-ut61e-true-rms-multimeter/)
(edit2) Tenma has some discounts on beefed up UT61E (non plus)
https://www.eevblog.com/forum/buysellwanted/newark-sale-on-many-tenma-brand-meters/msg3655997/ (https://www.eevblog.com/forum/buysellwanted/newark-sale-on-many-tenma-brand-meters/msg3655997/)
Skimmed the Kerry Wong video but didn't notice anything beyond what Dave had gone over.
We could reorder the tests for this special meter. Start with the 100us transients. If it survives that (which it won't) then run the AC line test and then the ESD. Not sure we would learn anything more doing this. The end results the same.
UNI-T fanboys are already thinking I am biased against this meter. I can see the mass of down votes. lol. I have more than enough data now to know what to expect.
Hi,
I know this is reopening an old topic, but I would love to see how UT161E would fair in your tests.
Hi,
I know this is reopening an old topic, but I would love to see how UT161E would fair in your tests.
Why? If robustness is a big concern then you can buy a proper multimeter for that much money.
And how does the warranty work on the UNI-T in the USA?You can get warranty in the US for a "Uni-T like" by paying a steep premium from Farnell:
My other option is Brymen BM789 but I didnt want to spend that much and not sure how the warranty would even work on it, when its imported to US.As for Brymen in the US with warranty, Greenlee would be the brand to go. They don't have a BM789, but a BM869 instead. Paying a bit more than the originals, but it is the real deal. I just got a brand new DM200A (BM251S) on an eBay bargain (half of a UT61E+) and it is incredibly compact and well built, even features premium gold leads. :-+
And how does the warranty work on the UNI-T in the USA?You can get warranty in the US for a "Uni-T like" by paying a steep premium from Farnell:
https://www.newark.com/multicomp-pro/mp730679/dmm-true-rms-20a-1kv-22000-count/dp/64AJ4559?st=Tenma%20multimeter (https://www.newark.com/multicomp-pro/mp730679/dmm-true-rms-20a-1kv-22000-count/dp/64AJ4559?st=Tenma%20multimeter)
Terribly expensive for what it is. Even their old UT61E models do not have the promotional price anymore.
https://www.newark.com/tenma/72-10415/dmm-hh-10a-1kv-22000count/dp/94AC6580?st=Tenma%20multimeter (https://www.newark.com/tenma/72-10415/dmm-hh-10a-1kv-22000count/dp/94AC6580?st=Tenma%20multimeter)My other option is Brymen BM789 but I didnt want to spend that much and not sure how the warranty would even work on it, when its imported to US.As for Brymen in the US with warranty, Greenlee would be the brand to go. They don't have a BM789, but a BM869 instead. Paying a bit more than the originals, but it is the real deal. I just got a brand new DM200A (BM251S) on an eBay bargain (half of a UT61E+) and it is incredibly compact and well built, even features premium gold leads. :-+
Got anything close to 161e feature wise, better protection around $100?
161E goes on sale for $56 at times, if you can recommend anything better that has same features or more I'm open to suggestions.
If not, would 161e be safe while working on 240v 3 phase machines?
161 does have better fuses than 61E+. But I understand that nothing is 100% safe. I'm just saying I don't want it blowing up in my hands from that voltage.If not, would 161e be safe while working on 240v 3 phase machines?
No meter is 100% "safe" because there's always operator error. There's also a couple of pages now that are telling you that it's probably no better than the ordinary 61E, ie. the extra '1' in the name is mostly marketing.fluff to sell (practically) the same meter for more money.
The Fluke 101 is about as close as any meter gets to "safe" in untrained hands.
161 does have better fuses than 61E+.
I'm not a fan of carrying multiple multimeters
I wouldn't care much about 161e warranty for $50-60 price.There is no free lunch. The Fluke 101 is the strict low end of Fluke with robustness but zero features (and quality control issues in my experience). Brymen/Greenlee is what you are going to find with reasonable robustness and more features at the same price range (also Klein). The newer Uni-T models seem to have reasonable mechanical robustness, but electrically they are not as good.
Got anything close to 161e feature wise, better protection around $100?
If not, would 161e be safe while working on 240v 3 phase machines? I would mod it to make it more robust but not electrical engineer, and I know it's not allowed to ask for help with that here sadly.This is a question that can be approached from many angles.
... an Uni-T meter would be less robust than a Fluke/Brymen/Klein, but without testing no one can really know.
Thanks for the highlights. I haven't heard good things about older Klein DMMs - the MM2000 is an older design, although the MM500 seems somewhat newer, albeit both are discontinued.Quote... an Uni-T meter would be less robust than a Fluke/Brymen/Klein, but without testing no one can really know.
From my spreadsheet, I looked at a Klein MM2000 which was damaged with a 2kV transient . I also looked at an MM500 which was damaged at 5kV (much shorter FWHH). The MM500 was never exposed to any ESD transients.
The second UNI-T UT139C I tested where I crept up on it also failed at 5kV with the 100us FWHH but it survived the ESD tests.
From an electrical robustness standpoint, I wouldn't place Klein in the same class as Fluke and Brymen. Maybe Klein rebrands some better products that I have not looked at. Still we have looked at Fluke and Brymen's low end products and the results speak for themselves.
**
Which Klein product do you feel competes? Maybe we can have a look at that.
... I can only speculate.It funny how we see things so differently. I look at the following ad and notice the same super cheap leads and thermocouple I've found with so many low end meters our of China that I have sent to the recycle bin. I think, this meter has no chance of surviving to the same levels as the Flukes or the Brymens I have looked at. It would be lucky to survive ESE and maybe the low voltage transient generator. As you said earlier,
... but without testing no one can really know.
From an electrical robustness standpoint, I wouldn't place Klein in the same class as Fluke and Brymen.
From an electrical robustness standpoint, I wouldn't place Klein in the same class as Fluke and Brymen.
Maybe more interesting to look at something like these:
https://www.amprobe.com/product-category/multimeters/industrial-multimeters/ (https://www.amprobe.com/product-category/multimeters/industrial-multimeters/)
Looking at the claims... they ought to be the most robust meters out there. ;)
AC Volts (45 Hz to 2 kHz) transient protection: 12 kV impulse (1.2 µS/50 µS) based on EN 61010-1:2001 impulse requirement for at CAT IV 1000 V product. This product should not be used in installations where transients exceed 12 kV.but I don't just test the ACV mode. I used an Amprobe to set the cutoff of what I consider a robust meter. You may remember I ran a higher end Amprobe and it did very poorly.
They state:QuoteAC Volts (45 Hz to 2 kHz) transient protection: 12 kV impulse (1.2 µS/50 µS) based on EN 61010-1:2001 impulse requirement for at CAT IV 1000 V product. This product should not be used in installations where transients exceed 12 kV.but I don't just test the ACV mode. I used an Amprobe to set the cutoff of what I consider a robust meter. You may remember I ran a higher end Amprobe and it did very poorly.
If we wanted to find meters that were as robust as what I have seen with Fluke and Brymen, I would look at Gossen and Hioki. Both of these meters held up very well against my transient testing.
It's a wavetek original design ..... Wavetek hasn't been around for a long time. I wonder how old this meter is. Early 90s?
Sure, I'd like to see a Hioki DT4282 go under the hammer. Not only for robustness but to see how well it works ingeneral. :)
That channel is getting close to 20k subscribers. Like when it hit 2k, it seems like we should have a look at something special if it ever makes it up that high. Last time we had a lot of fun with a high end Gossen.
Indeed we see it differently. The thermocouple is visually similar to the Amprobe AM530 I had, the Agilent/Keysight U123x/U127x and a few others; the probes might be the cheaper models indeed, but the manufacturer sells replacements, so they are not necessarily a totally no-brand quality-uncontrolled product. The meter itself is quite well put together mechanically speaking (I had a MM700 once in my hands), and the manual (https://data.kleintools.com/sites/all/product_assets/documents/instructions/klein/MM700_1390112ART_WEB.pdf) is thorough enough with relevant specifications (RH%, Altitude, etc.) including drop test and independent verification.Quote... I can only speculate.It funny how we see things so differently. I look at the following ad and notice the same super cheap leads and thermocouple I've found with so many low end meters our of China that I have sent to the recycle bin. I think, this meter has no chance of surviving to the same levels as the Flukes or the Brymens I have looked at. It would be lucky to survive ESE and maybe the low voltage transient generator. As you said earlier,Quote... but without testing no one can really know.
And here is where the difference between robustness and safety relies. The last sentence is covered by the EN61010 but does not mean the meter will survive.They state:QuoteAC Volts (45 Hz to 2 kHz) transient protection: 12 kV impulse (1.2 µS/50 µS) based on EN 61010-1:2001 impulse requirement for at CAT IV 1000 V product. This product should not be used in installations where transients exceed 12 kV.but I don't just test the ACV mode. I used an Amprobe to set the cutoff of what I consider a robust meter. You may remember I ran a higher end Amprobe and it did very poorly.
Sanwa as well... The PC7000 (https://overseas.sanwa-meter.co.jp/products/digital_multimeters/index.html) is super nice and probably terribly expensive...If we wanted to find meters that were as robust as what I have seen with Fluke and Brymen, I would look at Gossen and Hioki. Both of these meters held up very well against my transient testing.
Sure, I'd like to see a Hioki DT4282 go under the hammer. Not only for robustness but to see how well it works ingeneral. :)
The last sentence is covered by the EN61010 but does not mean the meter will survive.
Indeed we both agree that it is wide open for interpretation - if it was the most stringent requirement (i.e., the meter survives) we would probably know by now. As I also said before, this perhaps is deliberate to cater to lower cost manufacturers - after all, these standards are frequently decided and agreed on committees comprised of representatives of various manufacturers.The last sentence is covered by the EN61010 but does not mean the meter will survive.
We covered this a few times here. I've gone so far as to site various sections from the standards and contacting a few of the manufactures. As I have stated, I could not get a consensus. If you know (know meaning with 100% certainly) what 61010 means, your are way ahead of me.
I think the only requirement is "fail safely". If the meter was required to survive then it would say so in the standard.Exactly my point. Rinse and repeat is all. No data.
This leaves the final decision in the hands of the manufacturers. If a manufacturer wants to build a reputation for "bomb proof" then they try to make their meters survive transients (and charge accordingly). If they don't want that reputation, then... whatever. :-//
To celebrate reaching 20k subscribers, the following list of handheld meters will be considered.That Metrix MTX3293B is also available under the Chauvin Arnoux brand, Chauvin Arnoux CA5293-bt
Brand model, requested by, link to manual
AEMC MTX 3293B, Bogdan Oliver, https://www.aemc.com/userfiles/files/resources/usermanuals/Multimeters/MTX3292B-3293B_EN.pdf (https://www.aemc.com/userfiles/files/resources/usermanuals/Multimeters/MTX3292B-3293B_EN.pdf)
I've added the Gossen just out of my own curiosity if they actually did do anything besides rename from Ultra to Prime.You're willing to buy another ~$1000 meter just to see if they added some shielding? :wtf: ;D
To celebrate reaching 20k subscribers, the following list of handheld meters will be considered.
Brand model, requested by, link to manual
Hioki DT4282, Fungus, https://www.hioki.com/euro-en/products/testers/dmm-4/id_5803 (https://www.hioki.com/euro-en/products/testers/dmm-4/id_5803)
Sanwa PC7000, rsjsouza, https://overseas.sanwa-meter.co.jp/download/index.html (https://overseas.sanwa-meter.co.jp/download/index.html)
AEMC MTX 3293B, Bogdan Oliver, https://www.aemc.com/userfiles/files/resources/usermanuals/Multimeters/MTX3292B-3293B_EN.pdf (https://www.aemc.com/userfiles/files/resources/usermanuals/Multimeters/MTX3292B-3293B_EN.pdf)
For me it's not just the electrical robustness testing, the quirks you find in the meters are the ones that I find most interesting. That is something other reviewers usually don't find. Maybe because they're sponsored, or maybe it requires that you have to spend real time with the meter going through everything and keep being alert. I think you have a real talent for that.Well said. Me too.
Hioki DT4282:
Its younger brother gave great performance in your tests. I doubt it will be any different.
You're willing to buy another ~$1000 meter just to see if they added some shielding? :wtf:Indeed. I'm surprised anyone would even question my insanity at this point! I waited a few years for the 121GW to mature before reviewing it. Seems we have givin Gossen more than enough time.
.... show others how to improve it ..... As an adult it seems irresponsible, not to mention potential liability. That is unless you are referring to my offering feedback to the manufactures to improve their products. There's a big difference when it comes to working with a group of professionals to solve problems.
I thought you don't care how many subscribers you get.I don't or I would do things much differently. Maybe just create some actual content once in a while. Still it seems fitting to celebrate that there are so many of you crazy people out there.
I've never had enough interest in the subject to contact the agencies. Have you? I doubt these agencies follow the EEVBLOG so I am not sure how we could know unless someone were to contact them. Otherwise, it's just a rinse and repeat cycle. We may even get a consensus on the forums of what we believe, but that's not data. As I stated, I went so far as to contact the manufactures and read the standards. I've provided feedback from both. If you have done anything further, I would like to hear your findings.Unfortunately I don't. I might have access to contacts on the cert agencies again later this year but, since liability about information is a critical part of their business, they tend to keep information quite compartmentalized across testing groups and therefore might not share anything that pertains to other class of products.
Sanwa PC7000:Interesting; I wasn't aware of (or perhaps forgot about) the PC7000 teardown - indeed it uses a BTC device inside. The other one I knew was the PC700 (https://youtu.be/3srAQ0KifPA).
After looking at its teardown, I am sure it is manufactured by Brymen since it is using Brymen branded chips. Even though these are lower specs models, I doubt they'll behave badly. If they do, it will be a slap in Brymen's face. MJLorton did a review and a teardown of this meter.
There is indeed a short teardown topic here on the forum:
If they haven't installed any shield inside this B model as well, you better buy that sheet metal you used to shield Gossen Ultra before ordering this meter.
Some time ago a few others had asked about looking at BenningI assume in that case you're thinking about the Benning M12, their top model?
and Testo.Looking at their meters, I'm not really blown away by their specs. It looks like all their meters are more targetted towards electricians/industry than electronics.
I should probably add the BM857S to the shortlist because that's the one I own. :)
But that would be boring. ;D
Before the tests start we already know it will be robust, there won't be any quirks, it'll be reliable and there will be no monumental screw ups in the design ;D
eg. One of the reasons I chose the BM857 is because there's almost no function overloading on the dial. People go on and on about the Fluke87V's simple user interface but this is even better. In a way the 857/859 are Brymen's most direct competitors to the 87V.
eg. One of the reasons I chose the BM857 is because there's almost no function overloading on the dial. People go on and on about the Fluke87V's simple user interface but this is even better. In a way the 857/859 are Brymen's most direct competitors to the 87V.
The 87 has never had a "simple" user interface. It has three different power up modes like centre zero bargraph mode etc.
I didn't record the model numbers and have not looked at what they offer. More just a reminder.Some time ago a few others had asked about looking at BenningI assume in that case you're thinking about the Benning M12, their top model?
....
That's also very interesing. Maybe more people here are contemplating whether or not to buy a high end keysight meter
I was not impressed with Keysight's lack of communication and how poorly the product performed but we could have a look at one of their high end meters.
Recently there was a person posting about measuring a carbon resistor and how much it was drifting. I made an attempt to replicate their tests and showed the effects of my walking into the lab, and then using a decent resistor.
I suspect that the Fluke they show has a much higher voltage with their resistor attached than their Brymen.
It's up to the buyer to pick the tools for their particular use.No my goal is not to improve the bm869s. Like I said I never work with these high values. I work more in the mV ranges and bought the meter specifically for the 500k mode in the DC mV range combined with the high accuracy and the possibility to have it calibrated according to iso17025.
.....
If your goal is to improve the BM869s, it would be best to open a discussion with Brymen.
It's up to the buyer to pick the tools for their particular use.No my goal is not to improve the bm869s. ... So maybe that was my goal :)
.....
If your goal is to improve the BM869s, it would be best to open a discussion with Brymen.
...but I am interested in where this quirk comes from and if it's possible to correct within reasonable means
I used that Caddock USVD2 2ppm 20.0007Meg resistor that is mounted in the foam as my reference.
To celebrate reaching 20k subscribers, the following list of handheld meters will be considered.
Please add the low budget KAIWEETS KM601 Smart meter.
Poll is now open.:-//
It worked fine for me. :-+Poll is now open.:-//
Seems locked here.
It's possible the people requesting I look at .....
The multimeter poll is currently neck and neck, and way more exciting than our federal election. :-DMM ::)TBH I want Joe to fry the KS and have them tell him as he is not a professional they will not support one of the products they have sold him. :-DD
When will it end? ??? and what happens if there is a draw? :-\
You KS fan boys do know I'm not going to open the box and talk about how great the product is without turning it on so you can feel good about your purchases. Keysight, if you're out there, hope you have your shit together.That is the idea here.
Someone finally voted for Benning. :-+
Looks like the KS is starting to pull away. Shame on me for adding it to the poll at the last minute. :-DD You KS fan boys do know I'm not going to open the box and talk about how great the product is without turning it on so you can feel good about your purchases. Keysight, if you're out there, hope you have your shit together.
13 week lead time. I'll start hunting around for stock.
***
Also, I want to thank everyone who took the time to vote.
Looks like the KS is starting to pull away.
... Patiently waiting for your review of KS (if KS will be the final pick).
Keeping in mind the slow response of GTDs and no MOVs in the circuit, my guess is it will not perform well with the transient testing, something like U1231A you tested. I may be wrong and the circuit may have better protection built into it. Only your practical tests will tell.
Would you kindly compare its functionality with 121GW (that is common among both) as both these meters are using the same DMM front end chip HY3131.
And thank you Joe for your efforts. Not many people including myself have tools and knowledge to check their equipment's limitations.
Much like any other voting. Very few will take the time to vote. Many will bitch about how the vote turned out. An infinite amount of resources is then spent trying to change the the outcome.Looks like the KS is starting to pull away.
Sock puppets. :P
Hi Joe,
You are right, I made a stupid mistake suggesting that GDTs are not as good as MOVs. I am sorry. Of course you've looked at the meters without MOVs that performed well, I just forgot while writing that message. Thank you for setting me straight and for the video suggestions.
Regarding the request for meter comparison, again I forgot you usually compare a bunch of meters while checking their functionality. I don't have anything particular in mind to test.
Seems like I have forgotten quite a few things. I need to refresh my memory and knowledge.
Qasim.
Interesting (or boring fits better), that Benning seems to switch from Appa to Brymen with its upcoming "High-End-Multimeter BENNING MM 7-2":-DD, which seems to be a further "Brymen 78X"? clone with a slightly different display arrangement, but same specs...same test leads...same type-k...
As always, if there's any non-destructive tests you would like to see before I run it, just let me know.
Suggesting that GDTs are not as good as MOV for this application is based on ignorance. [...]The ignorance is follow through current, which you do not include. Mains plus transients superimposed is a disaster with anything that crowbars such as GDT.
Why should you pay 325 Euro for this DMM, when any Brymen is that much cheaper? I don't get it, because I don't think, that they managed to improve the clonky rotary knob or the useless backlight-timer...but we will see at the end of 2022-07, when it should be available:There are several reasons to go for Benning, when you are in germany:
Suggesting that GDTs are not as good as MOV for this application is based on ignorance. [...]The ignorance is follow through current, which you do not include. Mains plus transients superimposed is a disaster with anything that crowbars such as GDT.
Fluke started with GDT and changed to MOV's, Brymen would have ditched the large MOV's long ago if they were practical.
I'd buy a GDT clock.
May have to turn it off when I want to use the WiFi though :-DD
Thanks for linking my video, despite being in Kling... *ahem* portuguese; I don't even remember what I said and tested on it, but I recall I didn't open it (it was still in warranty).
I look forward for your review and tests. It still ticks valiantly on my bench despite some mishaps in medium voltage.
Thanks for linking my video, despite being in Kling... *ahem* portuguese; I don't even remember what I said and tested on it, but I recall I didn't open it (it was still in warranty).
I look forward for your review and tests. It still ticks valiantly on my bench despite some mishaps in medium voltage.
I plan to work on small segments to allow people to provide feedback. I ran into a couple of snags right from the start. When you select the ACV function, then select frequency, how do you get it back to the standard mode? The only way I saw was to change the function and return back to ACV.
The other problem I see is I can get the frequency counter to work. Like the UNI-T meter, I wonder if they over spec'ed it. Does yours work?
I own a U1273A and a U1282A and had owned a U1233A. I haven't used the U1233A enough to have a strong opinion other than its size and packed features are a very nice feature. I tend to prefer the U1273A but the U1282A has its uses.
Leeching off bitseeker's excellent response, I have the following addenduns:
(I may be forgetting a few things)
U1273A:
- OLED display. The most controversial factor of this meter. Unbeatable indoors legibility and, if used in dark conditions, you will never be caught with a dark display (due to backlight timeout) while trying to evaluate the best places to put the probes. Its durability is unknown and various reports around this forum are concentrated on the previous model U1253 (only one or two concerned this model). Mine still works after 4~5 years of manufacturing (about 1-1/2 years of moderate use of about 1 hour per day). Threads here ([url]https://www.eevblog.com/forum/testgear/keysight-u1273a-heavily-discounted-at-fry_s/[/url]), here ([url]https://www.eevblog.com/forum/testgear/anyone-with-an-agilentkeysight-oled-dmm-still-happy-with-the-display-gt5-years/[/url]), here ([url]https://www.eevblog.com/forum/testgear/agilent-u1253b-display-becoming-unreadable/[/url]) and here ([url]https://www.eevblog.com/forum/testgear/agilent-u1253b-oled-slowly-going-bad/[/url]) (there may be others).
- Decent speed autorange.
- Frequency measurements do not require the signal to have zero crossing - good for signals with DC offset. (common to U127x/U128x)
- Various hold mechanisms (common to U127x/U128x), including a trigger (like an oscilloscope) and Auto hold.
- Built-in data logging with different trigger modes - the one I use the most is the event trigger, which allows to log only when a stable input is detected. (common to U127x/U128x)
- Low impedance ACV/DCV mode for eliminating ghost voltages (LoZ). Since in the bench I use several boards and power supplies and host PCs interconnected, this mode is quite useful to detect wide ground variations in unknown conditions. Lowest voltage difference is 3VAC - here ([url]https://www.eevblog.com/forum/testgear/dmms-with-lowz-feature/msg1407849/#msg1407849[/url])
- Can compensate for DC offset voltages when measuring resistance (smart ohms). I personally have seen myself using this mode more than I initially believed during my repairs around the house on HVAC, heater and other permanent installations.
- Good capacitance meter with excellent range: up to 33mF. Slow on auto-range, especially on higher ranges (somewhat expected).
- 3V Diode checker that tests in both directions so you don't have to swap the leads.
- Beep can only be fully disabled or fully enabled. No sensible settings to disable the turn on beep.
- Continuity tester has a very interesting melody setting. A gimmick.
- Uses AAA batteries (common to U127x/U128x). Not a big fan due to the fear of leakage, but this meter sees quite a bit of action and the batteries usually are replaced every 6~8 months with my use.
- Very well built and a bit tall for my taste, but it has good rotary switch and terminal jacks. The various buttons with the number of aggregated functions not always make much sense - I sometimes see myself pressing a number of buttons until I get what I want or just need to go back to the previous display.
- I love its leads (Dave dislikes them due to length) as they have banana jacks on both sides. Easy to plug accessories.
- Earlier versions, like mine, were sensitive to high-frequency RF on the input jacks that could alter the displayed value.
U1282A:
- LCD Display. Excellent size and quite clear.
- Its biggest drawback to me is the slow autorange.
- Frequency measurements do not require the signal to have zero crossing - good for signals with DC offset. (common to U127x/U128x)
- Various hold mechanisms (common to U127x/U128x), including a trigger (like an oscilloscope) and Auto hold. However, on this meter the switch between the different auto-hold modes only via a setup menu - the U127x cycles as you press the button. To me this detracts from the functionality.
- Built-in data logging with different trigger modes - the one I use the most is the event trigger, which allows to log only when a stable input is detected. (common to U127x/U128x). Other modes are manual and timed - quite useful as well.
- It has NCV with configurable sensitivity settings. Despite this, I find this NCV still too sensitive for reasonable use. I prefer to use my Fluke LVD2 that is a spot tester.
- Good capacitance meter with excellent range: up to 100mF. Slow on auto-range, especially on higher ranges (somewhat expected).
- It has square wave output with configurable duty cycle and frequency. Since the frequency is only switchable on the setup menu, it is somewhat cumbersome to use for my taste.
- It has an input for remote control to perform manual hold of measurements. Perhaps it has its uses for others, but I haven't seen the need to purchase its accessory.
- 3V Diode checker. Lacks the auto-diode feature of the U127x that I like.
- Beep can be disabled more sensibly than U127x - either disable the turn on beep (leaving continuity beep still on) or disable everything.
- Uses AAA batteries (common to U127x/U128x). Not a big fan due to the fear of leakage, especially because one of its big advertisements is the very long battery endurance. Better check them constantly.
- Very well built and large meter that can easily act as a weapon. It has rubbery feel rotary switch (if that is an issue or not it is a highly personal matter). The various buttons with the number of aggregated functions not always make much sense - I sometimes see myself pressing a number of buttons until I get what I want or just need to go back to the previous display. IP67 rated, but mine only sees action on the lab.
- Decent leads but do not allow plugging accessories.
- Came with USB accessory for firmware updating and data logging. A big plus to me.
- Did not come with the temperature probe. A fail in my opinion.
- Not plagued by high-frequency RF problem of the early U127x modes.
Interesting clips about autorange comparison and the melody setting (shameless plug)
Melody continuity:
[url]https://www.youtube.com/watch?v=fH6rL2U2oAI[/url] ([url]https://www.youtube.com/watch?v=fH6rL2U2oAI[/url])
Autorange comparison:
[url]https://www.youtube.com/watch?v=EWZ0OSjYnvg[/url] ([url]https://www.youtube.com/watch?v=EWZ0OSjYnvg[/url])
One of the most confusing aspects of the U1282A is its button interface. When you go to the Frequency, you can long press the "Dual" button and get back to AC. However, if you go to either period or duty cycle by pressing the same "Hz" button, you can't go back to V unless you press the "Hz" button to get to the frequency and then long press the "Dual". I end up flipping the rotary switch.
You can or can't? The frequency works alright, but there is a derating curve of sorts that is more aggressive on the VAC Hz function when compared to the MHz range. I recall I can get several hundreds of kHz out of it. The MHz range goes to many MHz IIRC (it is specified (https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf) to 10MHz)
- Frequency measurements do not require the signal to have zero crossing - good for signals with DC offset. (common to U127x/U128x)
What is the 100 division factor? Is it a special setting or an external probe (Sorry I do not have time to check the manual now).
A fast check on my U1282A showed that it worked at 1MHz with 4Vpp, but not at 2MHz.
You need to press the Range selection to get it to work above 2MHz.
Not even half the rated frequency, which is what I am finding as well. As I continued to increase the frequency, the meter will display more than 2X the actual. Everything I tried ended with the same results.
The last meter I looked at was a UNI-T which advertised their counter over 200MHz. I wouldn't expect Keysight to be on par with the UNI-T brand but here we are.
HP > Agilent > Keysight > UNI-sigh
Not even half the rated frequency, which is what I am finding as well. As I continued to increase the frequency, the meter will display more than 2X the actual. Everything I tried ended with the same results.
The last meter I looked at was a UNI-T which advertised their counter over 200MHz. I wouldn't expect Keysight to be on par with the UNI-T brand but here we are.
HP > Agilent > Keysight > UNI-sigh
Hence my use of the derogatory "Keyshite". I am, sad to say, not surprised in the least.
In this intro video, I go through a basic checkout which includes looking at the frequency function.
https://www.youtube.com/watch?v=QFino110A0c (https://www.youtube.com/watch?v=QFino110A0c)
Your wife's comment about the Uni-T and the annoying beeping when turning the knob definitely rang home to me. Why do they always insist on them beeping when pressing buttons or turning knobs, it's so annoying.
FYI, mine came without documentation. While the contents paper states it comes with it, there is a paper that talks about them going green. No problem. I go to get the manuals and the first thing they want was my email address. Google search found the direct links. I'm fine with electronic copies but don't make me have to create an account to gain access to them.The paper document that came with it was not very useful. Regarding the e-mail account, this is somewhat recent. Pretty stupid.
Interesting; there are two tables: one named Frequency specification for U1281A / U1282A at page 14 which states 9.9999MHz and another named Frequency counter specification for U1282A at page 16 which states up to 99.999MHz with a "divide-by-100" and up to 1.8VP spec. This last one works on the MHz range selection.You can or can't? The frequency works alright, but there is a derating curve of sorts that is more aggressive on the VAC Hz function when compared to the MHz range. I recall I can get several hundreds of kHz out of it. The MHz range goes to many MHz IIRC (it is specified (https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf) to 10MHz)
Unless I am not understanding the document you linked, they claim 100MHz.
From your post:Quite interesting your meter fails on this. Mine does not, in both VAC and MHz.Quote- Frequency measurements do not require the signal to have zero crossing - good for signals with DC offset. (common to U127x/U128x)
The meter I have appears to require the zero crossing. You can't use it to look at digital signals for example.
This can be turned off via the setup menu, leaving only the button beeps (which are also annoying IMHO), the continuity buzzer and the Vsense.Your wife's comment about the Uni-T and the annoying beeping when turning the knob definitely rang home to me. Why do they always insist on them beeping when pressing buttons or turning knobs, it's so annoying.
Yep.
It could be a really short "bip", too, that might be tolerable, but noooo... it has to be "beeeeeeeeeeeeeep". Every. Single. Time. :palm:
We're only one video in and it's already confirmed what I suspected, ie. that Keysight meters are horrible. I could buy three top-of-the-range Brymens for the price of that meter and still have change left over for a nice dinner.
I have a BM789 and was so excited to learn that I could turn off the beeper until I found that it also disabled it for continuity etc. |O. O well, at least it's still better than my Ideal clamp meter... That dang thing lets out the loudest most annoying beep any time it senses over 40V :palm:The U127x is also like that - enable all or disable all.
Interesting; there are two tables: one named Frequency specification for U1281A / U1282A at page 14 which states 9.9999MHz and another named Frequency counter specification for U1282A at page 16 which states up to 99.999MHz with a "divide-by-100" and up to 1.8VP spec. This last one works on the MHz range selection.The manual you linked is clear about which is the Frequency Counter. I assume that divide statement is just showing that the resolution has changed, not that the meter requires some sort of external clock divider. If they did require such a device, they make no reference to it in the accessories or show it's use in any of the manuals that I found. I also can't imagine anyone spec'ing their 1Hz counter to 1THz with unknown accuracy, provided to attached the 1THz divider. Maybe the bottom of the bowl companies.
One of the best features of the Flukes 87V, 179 and 189, the Brymen BM857 and the UT-61E is they are quite silent. :=\
Not even half the rated frequency, which is what I am finding as well. As I continued to increase the frequency, the meter will display more than 2X the actual. Everything I tried ended with the same results.
The last meter I looked at was a UNI-T which advertised their counter over 200MHz. I wouldn't expect Keysight to be on par with the UNI-T brand but here we are.
HP > Agilent > Keysight > UNI-sigh
Hence my use of the derogatory "Keyshite". I am, sad to say, not surprised in the least.
Yeah, really bad meter, specifications says 20MHz and it can show up to 36MHz.
The meter is inside specifications. The way the specifications are stated makes it very easy to assume the meter can do more than specified and it can, but not as much as it looks like.
So, you don't see it as a problem that they are resorting to marketing bs/misleading statements in the manual, instead of engineering excellence, as they would have in the past?
So, you don't see it as a problem that they are resorting to marketing bs/misleading statements in the manual, instead of engineering excellence, as they would have in the past?
It do not make the meter bad, it may still be "engineering excellence".
I’m confused. Which misleading statement in the manual?
There are so many compounding problems with frequency measurement on DMMs that it’s difficult to recommend them as suitable after about 200KHz or so.
Just to note I have owned a keysight handheld. One of the lower end non OLED units from the last redesign series. The user interface was absolutely dire and some of the features such as touch hold were completely useless. And disappointingly one of the buttons was sticky out of the factory. If they’d spent a couple more months on it, it’d be a good meter. I wouldn’t buy another keysight handheld b
You can or can't? The frequency works alright, but there is a derating curve of sorts that is more aggressive on the VAC Hz function when compared to the MHz range. I recall I can get several hundreds of kHz out of it. The MHz range goes to many MHz IIRC (it is specified (https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf) to 10MHz)
Unless I am not understanding the document you linked, they claim 100MHz.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=1559392)
I wasn't sure which band you referred when mentioned the 100MHz, so I had to check and found the second table of the MHz range. My first message was clearly stating the first table that goes up to 9.9999MHz, which may correspond to the VAC range. Regarding the divider, it was just to highlight what the table meant, not implying you were doing something wrong by not using any external device/accessory - I too can infer they mean a reduction in resolution.Interesting; there are two tables: one named Frequency specification for U1281A / U1282A at page 14 which states 9.9999MHz and another named Frequency counter specification for U1282A at page 16 which states up to 99.999MHz with a "divide-by-100" and up to 1.8VP spec. This last one works on the MHz range selection.The manual you linked is clear about which is the Frequency Counter. I assume that divide statement is just showing that the resolution has changed, not that the meter requires some sort of external clock divider. If they did require such a device, they make no reference to it in the accessories or show it's use in any of the manuals that I found. I also can't imagine anyone spec'ing their 1Hz counter to 1THz with unknown accuracy, provided to attached the 1THz divider. Maybe the bottom of the bowl companies.
If you can, try to see how high your meter can actually read frequency using the frequency counter function.I need to find where I put my RF generator, but I got a very accurate measurement using my 30MHz generator set to 1.0VPP on the MHz function.
Earlier in the manual it only specifies it up to 9.9999 MHz... confused yet?
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=1559899)
Maybe I am the only one who found the attached comment a bit odd. It's a very old meter and has been reviewed before including by Dave.
It's no problem if you don't want to run it. I wasn't accusing anyone of being a fanboy. This was a brand new meter and I was just curious if Keysight's older revisions may have performed better.Cool; I just wanted to be sure. :-+
Maybe I am the only one who found the attached comment a bit odd. It's a very old meter and has been reviewed before including by Dave.
Very strange...
It's no problem if you don't want to run it. I wasn't accusing anyone of being a fanboy. This was a brand new meter and I was just curious if Keysight's older revisions may have performed better.Cool; I just wanted to be sure. :-+
I will watch your two videos and let you know of any discrepancies - after all, any manufacturer has the "right to change the product without prior or express warning". :-/
(Been caught on that a few times).
One just describes the drift, which could be well within the accuracy. Say for example, we wanted to compensate for that error to tighten the measurement.
One just describes the drift, which could be well within the accuracy. Say for example, we wanted to compensate for that error to tighten the measurement.
I always thought that the temperature coefficient was additional error that needed to be added to the published specification when outside of the specified (usually 18-28C) range. Is my interpretation wrong?
I got to run it on the signal generator; up to -30dBm I got about 19MHz; at at -20dBm I got 25MHz, -10dBm I got about 27MHz and at 0dBm I got 31MHz.It's no problem if you don't want to run it. I wasn't accusing anyone of being a fanboy. This was a brand new meter and I was just curious if Keysight's older revisions may have performed better.Cool; I just wanted to be sure. :-+
I will watch your two videos and let you know of any discrepancies - after all, any manufacturer has the "right to change the product without prior or express warning". :-/
(Been caught on that a few times).
It's just very odd how it behaves. It's very repeatable and appears independent of the amplitude (within reason) and wave shape. I tried both a sine as well as a squareish wave, using both LVDS and PECL drivers. I've also tried various terminations, none of which seems to matter. Not all of that made it on the video as I didn't see it adding anything. Had it made any difference in how the meter responded, I would have left it in.
Let me start by stating I would always turn to the manufacture to explain any questions I have about a specifications.
Hope you have a registered VAT number then :-DD
Did Keysight ever send you any kit?
(...)I did some tests of crest response and autorange speed of various meters on my channel, including the U1282A. The video is in portuguese, though.
-Crest mode, also with current (If that would not be part of the standard procedure.)
Edit:
-Continuity current, and range, also how it keeps the false alarms at bay (or not.) This might be tested on a real circuit.
Thanks in advance!
If the meter is not destroyed yet, than here is my wish list:For those not aware, background for this may be found here:
-The controversal dc biased AC mV overload test, which you were also doing earlier on some meters.(Not on video but were posting the results here in the forum.)
-Display update speed when measuring changing current. (You did a comparison once on different meters.)
-General current reading capability, to test its freq limit, its response to different waveforms, especially square waves which could come from a VFD, also with low duty cycles.
-Crest mode, also with current (If that would not be part of the standard procedure.)
Edit:
-Continuity current, and range, also how it keeps the false alarms at bay (or not.) This might be tested on a real circuit.
Thanks in advance!
Regarding false alarms, the U1282A is very strident with its Vsense and the input jack alert, which is more a scream whenever you switch to any current range. This is a reason why I don't use it in current ranges - it is excessively annoying and I can't think of a single reason why someone would think this was a good idea.
To try and warn the beginner that once they move that lead, that meter presents basically a short and whey they go to try and measure their home outlets current by placing the meters lead directly into the outputs, they are in for a surprise. :-DD
I installed the software for the meter. I have to say, the software UNI-T and CEM has provided would be much better for my needs and that should say it all.
joe smith
8 hours ago
I have the software installed and I guess working. What are the requirements for what you are attempting to measure? Saying resistance of a cryo coil doesn't tell me much. What is the value you are expecting to read, what sort of accuracy, how much drift do you expect from the test coil? Have you looked at the specs for the meter and you know it it is capable of making the measurement you need? It's easy to waste a bunch of time taking useless data. I would like to make sure I understand what you are looking for and then we can perhaps use a low tempco resistor in that same range to check it. Obviously, you know it's not a 4-wire Kelvin bench device and it wouldn't compare to even my old bench meters.
Chuan Liu
2 hours ago
@joe smith My colleague is expecting the copper coil resistance to drop from 8 ohm to around 1 ohm within several minutes, and maintain that level for several hours. The accuracy of this meter's 60 Ohm range is 0.15 % + 20, which is not impressive, but it is acceptable for the purpose at the current stage. I would like to find out if the meter can maintain its accuracy and linearity within a prolonged period. If the meter can maintain a good linearity, I think the data would still be usable, even with a lower accuracy. We are expecting to receive some microohm meters with proper 4-wire leads sometime in the future. Maybe we can use it to adjust the offset afterward, providing the Keysight meter can maintain a good linearity. Another way is to use a current source to inject a constant current through the coil and sue the meter to measure the voltage drop, but the accuracy of the current source will have an impact on the result, which we need to do some math with. Therefore I'd like to find out the meter's accuracy and linearity on both DCV range and resistance range. We do have some bench meters, but they are quite old and we don't have any suitable hardware to setup the PC connection.
I am only interested whether the overload would be indicated or not.If the meter is not destroyed yet, than here is my wish list:For those not aware, background for this may be found here:
-The controversal dc biased AC mV overload test, which you were also doing earlier on some meters.(Not on video but were posting the results here in the forum.)
-Display update speed when measuring changing current. (You did a comparison once on different meters.)
-General current reading capability, to test its freq limit, its response to different waveforms, especially square waves which could come from a VFD, also with low duty cycles.
-Crest mode, also with current (If that would not be part of the standard procedure.)
Edit:
-Continuity current, and range, also how it keeps the false alarms at bay (or not.) This might be tested on a real circuit.
Thanks in advance!
https://www.eevblog.com/forum/testgear/brymen-bm789/ (https://www.eevblog.com/forum/testgear/brymen-bm789/)
There's some pretty funny posts in the thread. One year later, I still see it as a pointless case outside of a bit of entertainment it may provide. Like I mentioned back then I will use a blocking cap and that hasn't changed.
So while I am sure I can find cases where the Keysight has problems, that's nothing I would hold against the meter.
Rarely I do anything with the current inputs on these meters. Any idea what video shows the test you are interested in? If so, provide a link and I will see about replicating it.
I installed the software for the meter. I have to say, the software UNI-T and CEM has provided would be much better for my needs and that should say it all.The SW generally works well for me (although I am on Windows 8 and not the newfangled 10), but the biggest annoyance is that is requires MS Office installed for any reporting/export functions. That is a PITA as I haven't installed MS Office in years in my PCs (I use some really excellent clones such as the Softmaker Freeoffice).
I change the sample rate to 10 seconds, stop and restart, it still runs a 1sps. I try to change where it logs data but it doesn't seem to allow it. Zoom into an area, sorry, you can't really. Stats, what are stats. Looks like you can export the data to Excel but say the system dies. You now have this XML file. Where's the import function and post processing? It seems to have a lot of features to stay in touch with me while I am out playing a round of golf or getting my foo foo drink. I don't golf and drink black coffee and so these features are useless in that respect. Looks more like one of the marketing employee's kids wrote it than a group of professionals.
On the plus side, they did at least document the commands so putting something together wouldn't take a lot of effort.
Someone asked about running some day long tests. I plan to let it run and see if the software is at least stable and that I can get the data into a useful format.
If you use their software, what's been your experience? Think its the best data capture software ever created? Crash and burn on you a lot?
***
I see the import data.
Tried the export to CSV. Still would need a way to do something with the data.
Don't press report unless you want to restart the app as it seems to hang it.
The only way I have found to clear the plot was to exit the software and restart it.
Good stuff...
For those not aware, background for this may be found here:I am only interested whether the overload would be indicated or not.
https://www.eevblog.com/forum/testgear/brymen-bm789/ (https://www.eevblog.com/forum/testgear/brymen-bm789/)
There's some pretty funny posts in the thread. One year later, I still see it as a pointless case outside of a bit of entertainment it may provide. Like I mentioned back then I will use a blocking cap and that hasn't changed.
So while I am sure I can find cases where the Keysight has problems, that's nothing I would hold against the meter.
Rarely I do anything with the current inputs on these meters. Any idea what video shows the test you are interested in? If so, provide a link and I will see about replicating it.
The topic with many meters tested for this is actualy this one:
https://www.eevblog.com/forum/testgear/brymen-multimeters-fault/ (https://www.eevblog.com/forum/testgear/brymen-multimeters-fault/)
Maybe one or two meter passed this test from all of yours.
You were having the meters in series and changing the test current. Some meters were responding really Slowly.You may have noticed from watching reviews for this Keysight that it is very slow. I think the Martin (??) guy had made a video showing how it compared. I think Dave may have made one as well. You may want to try searching YT and see what's out there. It's an old meter and many people have looked at it.
Now that you made your wife to be the standard switch-feeling tester, it is a pity that you didn't show her the dt830 meter.I didn't want to waste too much of her time but thought it was interesting that the Fluke 87V and UNI-T shown were both subjected to the 50,000 cycle life test and still have a better feel than the Keysight. I never would have guessed she would like the BM869s. Many people complain about how tight the switch is and the small knob.
Hi! The 1282 Is specified in Crest mode with repetitive signals down to 250 microseconds, so it should go further down than in your test.(...)I did some tests of crest response and autorange speed of various meters on my channel, including the U1282A. The video is in portuguese, though.
-Crest mode, also with current (If that would not be part of the standard procedure.)
Edit:
-Continuity current, and range, also how it keeps the false alarms at bay (or not.) This might be tested on a real circuit.
Thanks in advance!
Crest
https://youtu.be/ZDGdnGpG3ho
Autorange
https://youtu.be/EWZ0OSjYnvg
Regarding false alarms, the U1282A is very strident with its Vsense and the input jack alert, which is more a scream whenever you switch to any current range. This is a reason why I don't use it in current ranges - it is excessively annoying and I can't think of a single reason why someone would think this was a good idea.
I did not state that any meter was perfect, it was only about this specific test. Maybe the extech was the only one with ac+dc mV scale which passed it.
I'm not aware of any meters I have that are perfect. If you feel there were, let me know which and I can have another look. It is very possible that someone has a specific case they were running and I had meters that would handle it but let's be clear that doesn't suggest they wouldn't have other problems. As shown in the photo, you could see that Keysight is no exception.
You were having the meters in series and changing the test current. Some meters were responding really Slowly.You may have noticed from watching reviews for this Keysight that it is very slow. I think the Martin (??) guy had made a video showing how it compared. I think Dave may have made one as well. You may want to try searching YT and see what's out there. It's an old meter and many people have looked at it.
Now that you made your wife to be the standard switch-feeling tester, it is a pity that you didn't show her the dt830 meter.I didn't want to waste too much of her time but thought it was interesting that the Fluke 87V and UNI-T shown were both subjected to the 50,000 cycle life test and still have a better feel than the Keysight. I never would have guessed she would like the BM869s. Many people complain about how tight the switch is and the small knob.
The SW generally works well for me (although I am on Windows 8 and not the newfangled 10), but the biggest annoyance is that is requires MS Office installed for any reporting/export functions. That is a PITA as I haven't installed MS Office in years in my PCs (I use some really excellent clones such as the Softmaker Freeoffice).That may be why the report generator locks up. I have Office installed.... 97! :-DD I refuse to change it as IMO, it started going down hill after this. Anytime I have to use the latest Office tools today, part of my soul dies.
I did not state that any meter was perfect, it was only about this specific test. Maybe the extech was the only one with ac+dc mV scale which passed it.
I'm not aware of any meters I have that are perfect. If you feel there were, let me know which and I can have another look. It is very possible that someone has a specific case they were running and I had meters that would handle it but let's be clear that doesn't suggest they wouldn't have other problems. As shown in the photo, you could see that Keysight is no exception.
Possibly the waterproof washer is the problematic part. Still, nex time show her the dt830 as well, just to have an objective oppinion :)I don't think that's going to happen any time soon but you are certainly free to ask your wife to run what ever test you like.
Pulled out my favorite meter of all time, the lime green TIP 194 II. Now keep in mind this meter is currently damaged and has high leakage on one of the controllers port pins that effects the resistance measurements.
In DCmV the meter over ranges at +/-500mV.
In ACmV the meter over ranges at 1.417Vp-p or again 500mV RMS (60Hz sinewave)
With 490mVRMS biased with 400mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 499.9mV with 490mV RMS applied, the meter provides the correct readings for both.
Next I apply 600mV of bias to our 490mV RMS signal and of course the DCmV reading is now out of range. But the ACmV reading is now effected again with no indication that there is a problem. With 1VDC bias the ACmV is all the way down to 374mV.
The TPI 194II does support the AC+DC and is a tri-display. But sadly this is not supported in mV ranges. It's too bad I could not get a controller to replace the one on the meter. I would have then attempted to improve it like I show with that low end UT61E.
**********************************************************************************************
Looking at the Extech EX540
In DCmV the meter over ranges at +/-412mV.
In ACmV the meter over ranges at 1.168Vp-p or again 412mV RMS (60Hz sinewave)
With 409mVRMS biased with 400mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 500mV, the meter over ranges on the DCmV but there is a slight effect on the ACmV.
With 1VDC bias the ACmV is down to 399mV which is better than the TPI 194 II but it's an error and there again is no indication that there is a problem.
This meter also supports AC+DC calculations and appears to show an over range for any combination that goes above 412mV.
**********************************************************************************************
And I'm sure everyone wants to know the UNI-Ts top of the line UT181A does. Again this meter was damaged like the TPI with one hit from the grill starter. I was able to repair it and made some pretty drastic mods to the PCB. This meter is not original but I do not believe I changed anything that would effect this test.
In DCmV the meter over ranges at +/-612mV.
In ACmV the meter over ranges at 1.731Vp-p or again 4612mV RMS (60Hz sinewave)
With 610mVRMS biased with 600mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 700mV, the meter over ranges on the DCmV but the ACmV is correct.
With 1VDC bias the ACmV is down to 587mV and again there is no indication that there is a problem.
This meter will calculate AC+DC and has a tri-display. In this mode with the same 1VDC bias, the AC+DC and mVDC are both over ranged but the mVAC shows the 587mVAC which is of course not correct. But if the OL were not enough to sway the user into thinking there may be a problem with their measurement, they go one step further and enable the yellow triangle with the lightning bolt. Still, really it's not full proof and the ACmV should show an error as well or you just know someone is going to trust that number...
**********************************************************************************************
Scott's going to ask about the Fluke 97. That's a special snowflake as it auto ranges both the AC and DC values. You exceed the mV range, it will switch.
I don't disagree with the OP that there is a problem with some meters showing inaccurate results under certain conditions without any warning to the user. Hopefully running these few meters shows that this is not something unique to one brand.
I'm surprised you would consider using a 2-wire approach below 10.
When using the this meter, I will do some software tricks to improve the measurement.
I would expect what you are asking to be a paper study more than anything.
Shown after 7 hours with a 40R0000 0.005% +/-1ppm S102K attached. Meter just setting on my desk in open air (no temp control). After 3 hours, something happens that we see a spike down to 1.239 ohms. There is nothing going on during this time. Office is closed off. So I am going to suggest the software/firmware/hardware has a problem. Zooming into this area, and ignoring the glitch we can see the meter changes 2 counts. I have a low tempco 0.5ohm I'll attach and let it run for the day.
To be more specific:Pulled out my favorite meter of all time, the lime green TIP 194 II. Now keep in mind this meter is currently damaged and has high leakage on one of the controllers port pins that effects the resistance measurements.
In DCmV the meter over ranges at +/-500mV.
In ACmV the meter over ranges at 1.417Vp-p or again 500mV RMS (60Hz sinewave)
With 490mVRMS biased with 400mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 499.9mV with 490mV RMS applied, the meter provides the correct readings for both.
Next I apply 600mV of bias to our 490mV RMS signal and of course the DCmV reading is now out of range. But the ACmV reading is now effected again with no indication that there is a problem. With 1VDC bias the ACmV is all the way down to 374mV.
The TPI 194II does support the AC+DC and is a tri-display. But sadly this is not supported in mV ranges. It's too bad I could not get a controller to replace the one on the meter. I would have then attempted to improve it like I show with that low end UT61E.
**********************************************************************************************
Looking at the Extech EX540
In DCmV the meter over ranges at +/-412mV.
In ACmV the meter over ranges at 1.168Vp-p or again 412mV RMS (60Hz sinewave)
With 409mVRMS biased with 400mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 500mV, the meter over ranges on the DCmV but there is a slight effect on the ACmV.
With 1VDC bias the ACmV is down to 399mV which is better than the TPI 194 II but it's an error and there again is no indication that there is a problem.
This meter also supports AC+DC calculations and appears to show an over range for any combination that goes above 412mV.
**********************************************************************************************
And I'm sure everyone wants to know the UNI-Ts top of the line UT181A does. Again this meter was damaged like the TPI with one hit from the grill starter. I was able to repair it and made some pretty drastic mods to the PCB. This meter is not original but I do not believe I changed anything that would effect this test.
In DCmV the meter over ranges at +/-612mV.
In ACmV the meter over ranges at 1.731Vp-p or again 4612mV RMS (60Hz sinewave)
With 610mVRMS biased with 600mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 700mV, the meter over ranges on the DCmV but the ACmV is correct.
With 1VDC bias the ACmV is down to 587mV and again there is no indication that there is a problem.
This meter will calculate AC+DC and has a tri-display. In this mode with the same 1VDC bias, the AC+DC and mVDC are both over ranged but the mVAC shows the 587mVAC which is of course not correct. But if the OL were not enough to sway the user into thinking there may be a problem with their measurement, they go one step further and enable the yellow triangle with the lightning bolt. Still, really it's not full proof and the ACmV should show an error as well or you just know someone is going to trust that number...
**********************************************************************************************
Scott's going to ask about the Fluke 97. That's a special snowflake as it auto ranges both the AC and DC values. You exceed the mV range, it will switch.
I don't disagree with the OP that there is a problem with some meters showing inaccurate results under certain conditions without any warning to the user. Hopefully running these few meters shows that this is not something unique to one brand.
Sorry for the late reply. It's been a long day. A inverter drive I was using decided to give up and released some magic smoke, which is quite strange since we were only running it at no more than 10% of its rated power.I'm surprised you would consider using a 2-wire approach below 10.
I agree using the 4-wire method is more appropriate. This is a side project and the support we can get is quite limited. We need something that can log the measurement automatically. It is either this or an old general purpose data logger. We do have some Keithley bench meters but we don't have any GPIB compatible PC to log the data. Hopefully the situation will change soon, if my colleague can get some funding.When using the this meter, I will do some software tricks to improve the measurement.
That sounds interesting. I wonder if you could kindly share some details about these tricks?I would expect what you are asking to be a paper study more than anything.
Not purely on paper. I would say this is a preliminary experiment to test the viability of liquid hydrogen cooling. However it is still far away from full scale experiment or even a technological demonstrator.Shown after 7 hours with a 40R0000 0.005% +/-1ppm S102K attached. Meter just setting on my desk in open air (no temp control). After 3 hours, something happens that we see a spike down to 1.239 ohms. There is nothing going on during this time. Office is closed off. So I am going to suggest the software/firmware/hardware has a problem. Zooming into this area, and ignoring the glitch we can see the meter changes 2 counts. I have a low tempco 0.5ohm I'll attach and let it run for the day.
Thanks for sharing these. The glitch looks similar to what I experienced before on a Keithley 2700. Other than that the drift doesn't look so bad. Definitely better than my Gossen calibrator. Did you connect the resistor directly to the banana socket?
To be more specific:Pulled out my favorite meter of all time, the lime green TIP 194 II. Now keep in mind this meter is currently damaged and has high leakage on one of the controllers port pins that effects the resistance measurements.
In DCmV the meter over ranges at +/-500mV.
In ACmV the meter over ranges at 1.417Vp-p or again 500mV RMS (60Hz sinewave)
With 490mVRMS biased with 400mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 499.9mV with 490mV RMS applied, the meter provides the correct readings for both.
Next I apply 600mV of bias to our 490mV RMS signal and of course the DCmV reading is now out of range. But the ACmV reading is now effected again with no indication that there is a problem. With 1VDC bias the ACmV is all the way down to 374mV.
The TPI 194II does support the AC+DC and is a tri-display. But sadly this is not supported in mV ranges. It's too bad I could not get a controller to replace the one on the meter. I would have then attempted to improve it like I show with that low end UT61E.
**********************************************************************************************
Looking at the Extech EX540
In DCmV the meter over ranges at +/-412mV.
In ACmV the meter over ranges at 1.168Vp-p or again 412mV RMS (60Hz sinewave)
With 409mVRMS biased with 400mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 500mV, the meter over ranges on the DCmV but there is a slight effect on the ACmV.
With 1VDC bias the ACmV is down to 399mV which is better than the TPI 194 II but it's an error and there again is no indication that there is a problem.
This meter also supports AC+DC calculations and appears to show an over range for any combination that goes above 412mV.
**********************************************************************************************
And I'm sure everyone wants to know the UNI-Ts top of the line UT181A does. Again this meter was damaged like the TPI with one hit from the grill starter. I was able to repair it and made some pretty drastic mods to the PCB. This meter is not original but I do not believe I changed anything that would effect this test.
In DCmV the meter over ranges at +/-612mV.
In ACmV the meter over ranges at 1.731Vp-p or again 4612mV RMS (60Hz sinewave)
With 610mVRMS biased with 600mV DC, both the AC and DC millivolts readings are correct.
Raising the DC bias to 700mV, the meter over ranges on the DCmV but the ACmV is correct.
With 1VDC bias the ACmV is down to 587mV and again there is no indication that there is a problem.
This meter will calculate AC+DC and has a tri-display. In this mode with the same 1VDC bias, the AC+DC and mVDC are both over ranged but the mVAC shows the 587mVAC which is of course not correct. But if the OL were not enough to sway the user into thinking there may be a problem with their measurement, they go one step further and enable the yellow triangle with the lightning bolt. Still, really it's not full proof and the ACmV should show an error as well or you just know someone is going to trust that number...
**********************************************************************************************
Scott's going to ask about the Fluke 97. That's a special snowflake as it auto ranges both the AC and DC values. You exceed the mV range, it will switch.
I don't disagree with the OP that there is a problem with some meters showing inaccurate results under certain conditions without any warning to the user. Hopefully running these few meters shows that this is not something unique to one brand.
As I read it again, each meter had problems. Maybe you were not understanding what I had posted.
One side note, the TPI 194II has since been repaired. Well, I replaced the damaged IC. It was never aligned after this but at least now throws up some OKish sort of numbers.
What about Fungus's favorite meter, the Fluke 101? Fungus recommended that meter to me for the very first $50 shoot em up test I ran and it cam out a clear winner. The one I have has never been apart. Not even for a peak! It has survived every thing I have thrown at it to date and works great. It's an averaging meter but again not a big deal for what we are doing. Surely this is our perfect meter!
It has a mVAC range and appears to over range at 660.0mV AC RMS 60Hz sinewave. Injecting 1.7VACp-p meter reads roughly 600mV as expected. Adding 300mV DC of bias, the meter reads 13mV high. With 600mV bias, the meter reads 10mV low. At 1VDC bias, its now reading 480mV. At 1.9VDC bias, its all the way down to 85mV and no indication there is anything wrong! Big fail for the Fluke 101!
So again: The problem is when a meter does not give any indication on the ac+dc mV scale (dc coupled)that either AC or DC overranged, and displaying false ac values.:palm: :palm: :palm: While I would have thought with all of my other comments about none of this being any sort of concern for me everyone would have recognized the heavy sarcasm. :-DD
And the extech EX540 shows that it overranged. It was not PERFECT, but it gave some indications.
The problem was NOT whether the meter can read AC perfectly with unlimited DC bias which is usually specified (a least in case of Brymen) that it can not. The problem is the missing of any kind of indication that the DC bias is overranged to take the AC values with a grain of salt.
Joe Smith also didn't like this with a Fluke:What about Fungus's favorite meter, the Fluke 101? Fungus recommended that meter to me for the very first $50 shoot em up test I ran and it cam out a clear winner. The one I have has never been apart. Not even for a peak! It has survived every thing I have thrown at it to date and works great. It's an averaging meter but again not a big deal for what we are doing. Surely this is our perfect meter!
It has a mVAC range and appears to over range at 660.0mV AC RMS 60Hz sinewave. Injecting 1.7VACp-p meter reads roughly 600mV as expected. Adding 300mV DC of bias, the meter reads 13mV high. With 600mV bias, the meter reads 10mV low. At 1VDC bias, its now reading 480mV. At 1.9VDC bias, its all the way down to 85mV and no indication there is anything wrong! Big fail for the Fluke 101!
I'll let that resistor run a few more hours then post the data for it. Maybe from there, you can decide if there is something else you would like to see.
Do you find that the system will glitch as I saw for longer captures?Glitch? I haven't seen any issues. Long captures were not a problem as shown below (albeit with my U1273A)
As in that first shot. Keep in mind you are only three minutes of data. I was showing 7 hours. That glitch was after 3 hours with a 10 second sample rate.Do you find that the system will glitch as I saw for longer captures?Glitch? I haven't seen any issues. Long captures were not a problem as shown below (albeit with my U1273A)
That was an older capture, but the total was more than twenty minutes of data without a glitch (not three). I can retry with the U1282A, but I won't promise a runlength of hours.As in that first shot. Keep in mind you are only three minutes of data. I was showing 7 hours. That glitch was after 3 hours with a 10 second sample rate.Do you find that the system will glitch as I saw for longer captures?Glitch? I haven't seen any issues. Long captures were not a problem as shown below (albeit with my U1273A)
I let the meter run for about 14 hours with a 1mV source attached. Again, the meter was just sitting on my desk without any temperature control. This time the sample rate was set to 1Hz. Once again, we see a downward glitch. Also, like the last time this is during the night with everything shut down.
If we ignore the glitch and zoom into the baseline, it looks like it drifts about 8 counts. Keeping in mind these measurements all include the standards and I am not suggesting this is all the meters doing.
Let me know if this answers your question. I am not happy seeing these two glitches in the data. The fact I have seen it twice now and once with nothing more than a resistor attached, it seems there is something wrong with the software/firmware/meter as this isn't something I would expect to see.
Thanks for sharing this. I guess the voltage across the resistor during the resistance test was much higher than 1 mV, so the drift wasn't picked up. Do you think if you could do another resistance test with the 0.5 Ohm resistor to see if the drift would appear?
That was an older capture, but the total was more than twenty minutes of data without a glitch (not three). I can retry with the U1282A, but I won't promise a runlength of hours.
Thanks for repeating this test. Going back and looking at the first time I ran it, they both dropped to around 1.5. So not exactly 0. So far, every time I have seen it glitch, it is always towards a lower value.
I'm surprised they wouldn't have caught something like this but then again, that counter spec doesn't give me any comfort.
With them recently sending that one reviewer a meter, they may be able to provide them feedback.
Chance92 and others would have to decide if its going to be a problem for them. I can imagine if you are running a long term experiment and the signal is not stable as you expect, then your spending time trying to track down if it's something on your end or the equipment, that will get old fast. I guess, just something else to be aware of if you buy one of these meters.
Firmware revision updates:-
Version 1.02
- Initial release
Version 1.03 fixes several issues present in the previous release.
- Change microcontroller sampling period from 25ms to 12.5ms.
- Bug fix for CAP+NULL+AUTO wrong range.
- Faster LED response for continuity.
Version 1.04 fixes several issues present in the previous release.
- Change Ampere calibration limits from 70% to 80% to solve production calibration fallout.
- Improve Autozero limitation by recalculating Autozero and not loading Autozero default value when inputs are OL.
- Reset OP1 & AD1 before reading Autozero.
- Zero Timer change from 4.2 seconds to 6.2 seconds.
Version 1.05 includes the following fix.
- Disables DC Filter during measurement at ACmV mode.
Have you tried this test with any of your Brymens?
It would be interesting to see the signal at that point to see if it's data corruption or if the meter is sending incorrect data.
Have you seen anything like this on other meters you have tested?
Have you tried this test with any of your Brymens?
It would be interesting to see the signal at that point to see if it's data corruption or if the meter is sending incorrect data.
Ok, I put it to run while doing other things around the house. Indeed there was a glitch at around 40min mark for the U1282A.That was an older capture, but the total was more than twenty minutes of data without a glitch (not three). I can retry with the U1282A, but I won't promise a runlength of hours.As in that first shot. Keep in mind you are only three minutes of data. I was showing 7 hours. That glitch was after 3 hours with a 10 second sample rate.Do you find that the system will glitch as I saw for longer captures?Glitch? I haven't seen any issues. Long captures were not a problem as shown below (albeit with my U1273A)
I will probably test the U1273A and see if similar things happen, which might help isolate the issue to either the meter or the software.
So, the U1273A shows no glitch.
Well, that was quick. It's not a large dip but similar to the small one that I showed the last time. I'll let it run but it's down to the meter now. Good job Keysight!
Well, that was quick. It's not a large dip but similar to the small one that I showed the last time. I'll let it run but it's down to the meter now. Good job Keysight!
Hi Joe. Do you think if you could run it again with the min/max function enabled on the meter, so that we can see if this glitch would show on the display? This way we may be able to isolate the problem further.
Defpom's review is up.
Part 1
https://youtu.be/bFyJlMd35v0
Part 2
https://youtu.be/UgbDNE0KhhI
Defpom's review is up.
Part 1
https://youtu.be/bFyJlMd35v0
Part 2
https://youtu.be/UgbDNE0KhhI
LOL, yes up, but not publicly published yet, I wish youtube would hide unlisted videos from public playlists until the video gets made public, oh well.
Enjoy the early access I guess !
There are a few features I haven't tried using yet, logging is one of them, I have a lot on at the moment so I don't know when I will get to look at that.Lucky for me, logging requires very little of my time. Basically set the meter up and walk away. Well, I spend maybe an hour to put that simple program together, test their interface cable, then sort get it attached to the meter. Watching grass grow, paint dry, kettle boil.... all much more exciting.
Defpom's review is up.
Part 1
https://youtu.be/bFyJlMd35v0
Part 2
https://youtu.be/UgbDNE0KhhI
LOL, yes up, but not publicly published yet, I wish youtube would hide unlisted videos from public playlists until the video gets made public, oh well.
Enjoy the early access I guess !
Well, how things change....
So after changing the sample rate I captured another small glitch which first appeared to have an identical amplitude as the first. Zooming in, they are close but not the same. Then, shortly after I captured another large glitch.
I want to point out that the 4sps is a mistake and should have been five. Obviously Windows and Labview are going to have a timing error. The measured jumps around +/-1mS. So basically 5sps sample and the meter seems to keep up just fine. After the large glitch, it's been stable. I plan to continue to let it run.
It's starting to look more and more like the meter has a problem (hardware and or firmware).
Well, how things change....
So after changing the sample rate I captured another small glitch which first appeared to have an identical amplitude as the first. Zooming in, they are close but not the same. Then, shortly after I captured another large glitch.
I want to point out that the 4sps is a mistake and should have been five. Obviously Windows and Labview are going to have a timing error. The measured jumps around +/-1mS. So basically 5sps sample and the meter seems to keep up just fine. After the large glitch, it's been stable. I plan to continue to let it run.
It's starting to look more and more like the meter has a problem (hardware and or firmware).
Joe just curious when u think it might be a hardware issue do u suspect the chypset at all? Do any other meters based on the HY3131 have similar glitches?
Defpom's review is up.
Part 1
https://youtu.be/bFyJlMd35v0
Part 2
https://youtu.be/UgbDNE0KhhI
Right off the top though, he says that his U1282A was supplied by Keysight. If there's differing performance, could it be possible the sample unit specifically selected from a group of meters to make sure a good one was sent out for review vs. whatever you'd end up with by purchasing through regular retail channels?
The second question is why? That one I truly don't understand. If Keysight's going to be so painful to deal with for individuals and small businesses, why send meters out for review on YouTube?
I think the only other meter I looked at with that Hycon chipset was the 121GW.
If old age has taught me anything when it comes to solving problems, stay data driven. Don't let feelings cloud your judgement. :-DD
Personally, I blame this problem on those that voted for this meter!! You knew dam well I wouldn't just unbox it and give it five stars!! :-DD :-DD :-DD
I got to run it on the signal generator; up to -30dBm I got about 19MHz; at at -20dBm I got 25MHz, -10dBm I got about 27MHz and at 0dBm I got 31MHz.
We are using a 40 ohm resistor and the meter sends up something like: +4.00108000E+01. There's no missing data that would get us to what we are seeing. So far it appears random and can be reproduced without Keysight's software, drivers or interface cable.
I changed the test program to switch between two sample rates every 10 samples to see if that has any effect.
Personally, I blame this problem on those that voted for this meter!! You knew dam well I wouldn't just unbox it and give it five stars!! :-DD :-DD :-DD
We are using a 40 ohm resistor and the meter sends up something like: +4.00108000E+01. There's no missing data that would get us to what we are seeing. So far it appears random and can be reproduced without Keysight's software, drivers or interface cable.
I changed the test program to switch between two sample rates every 10 samples to see if that has any effect.
Personally, I blame this problem on those that voted for this meter!! You knew dam well I wouldn't just unbox it and give it five stars!! :-DD :-DD :-DD
Joe and Defpom videos showed that this DMM is so damn good and accurate, I really don't care about the 31MHz limitation, this is a secondary feature, just to compare, the Fluke 289 is only up to 1MHz, 1Vpp.
That Log glitch maybe could be fixed via Firmware, not a big deal since most people only use the Max/Min for a couple of seconds or minutes.
BTW, Congrats to Defpom, awesome tests, try to get a Fluke 289 to do the same tests.
My goal is to go beyond their specs and push the meters to failure to get some idea how electrically robust they are.
I'm not sure where these Keysight meters fit into things.
If I wanted a really "analytical" meter I'd go with the Fluke 289. It shows a lot of information on screen and doesn't seem to do anything badly.
If I anything over 100kHz (or even 20kHz...) I'd probably be using an oscilloscope, not a multimeter.
For anything under 100kHz I'm not sure why anybody would pay 3x more than a Brymen.
That's just me though. What would the owners say is the killer feature of these meters? Why did you buy one?
(not trying to derail the thread, I promise I'll sit and listen quietly)
I'm not sure if Fluke 289 has more features than Keysight U1282A, but both complement each other.
U1282A 4-batteries last more than 1000 hours, the 289 6-batteries won't last 10% of that.
Look at the image you posted - the 289 just shows the info much better:It is a tradeoff, where display complexity brings convenience at the expense of battery life and contrast (at least on the Fluke). The U1282A is closer to your typical portable multimeter (7-segment numerical display) than the graphical ones, so it is not necessarily a detriment to it.
(https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=1565968;image)
Datasheet says "up to 800": https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf (https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf)
Look at the image you posted - the 289 just shows the info much better:
We are using a 40 ohm resistor and the meter sends up something like: +4.00108000E+01. There's no missing data that would get us to what we are seeing. So far it appears random and can be reproduced without Keysight's software, drivers or interface cable.
I changed the test program to switch between two sample rates every 10 samples to see if that has any effect.
Personally, I blame this problem on those that voted for this meter!! You knew dam well I wouldn't just unbox it and give it five stars!! :-DD :-DD :-DD
Joe and Defpom videos showed that this DMM is so damn good and accurate, I really don't care about the 31MHz limitation, this is a secondary feature, just to compare, the Fluke 289 is only up to 1MHz, 1Vpp.
That Log glitch maybe could be fixed via Firmware, not a big deal since most people only use the Max/Min for a couple of seconds or minutes.
BTW, Congrats to Defpom, awesome tests, try to get a Fluke 289 to do the same tests.
When measuring VAC, I like that shows big numbers for Voltage and small for Frequency.
Keysight and Fluke are brands built over decades, even today we can see very used and abused Flukes and HPs with perfect accuracy, with no worries about calibration.
But, as I said, it's nice to have and use a Keysight U1282A, but there are other high-end and cheap DMMs.
So they are not indestructible by any means...[/b]
So they are not indestructible by any means...[/b]
I didn't say "indestructible" or "perfect", All products could require Repair services, the difference is the Frequency and Percentage of defective products.
Suppose a company buys 10 DMMs, after 3-years, we can see how many will be inoperable, and I guess Brymen won't last like Flukes and Keysights.
I'm sorry about your problem. Your DMM has an interesting feature "-40 to 55 °C operating temperature", this is useful for outdoor work in Cold and Hot places, very few DMMs can operate in that range.
Fluke 87V, Fluke 289, Keysight U1282A is "-20 °C to + 55 °C".
Brymen is only "0°C to 45°C"!!! is a pussy :-DMM for internal use only LOL
For anything under 100kHz I'm not sure why anybody would pay 3x more than a Brymen.
Sorry for the late reply. It's been a long day
....
Thanks for sharing these. The glitch looks similar to what I experienced before on a Keithley 2700. Other than that the drift doesn't look so bad. Definitely better than my Gossen calibrator. Did you connect the resistor directly to the banana socket?
I ran the battery life test tonight and as promised, I tried it in both DCV and resistance modes. With the 40ohm load, I was able to lower the battery voltage until the meter turns off without any change in the measurement. The same was true with a DCV source. I have seen this be a problem before so didn't hurt to check.
I have some other tests I want to run before we start the destructive testing so if there is anything else you would like me to look at, let me know.
Battery by sure is more than 1000 hours, ai never replaced the original batteries in 6 years (but I'm not sure how many hours I used it...)
We had gone through some simplified battery life tests before and I show the numbers below including the U1282ASorry for the late reply. It's been a long day
....
Thanks for sharing these. The glitch looks similar to what I experienced before on a Keithley 2700. Other than that the drift doesn't look so bad. Definitely better than my Gossen calibrator. Did you connect the resistor directly to the banana socket?
I ran the battery life test tonight and as promised, I tried it in both DCV and resistance modes. With the 40ohm load, I was able to lower the battery voltage until the meter turns off without any change in the measurement. The same was true with a DCV source. I have seen this be a problem before so didn't hurt to check.
I have some other tests I want to run before we start the destructive testing so if there is anything else you would like me to look at, let me know.
I ran the battery life test tonight and as promised, I tried it in both DCV and resistance modes. With the 40ohm load, I was able to lower the battery voltage until the meter turns off without any change in the measurement. The same was true with a DCV source. I have seen this be a problem before so didn't hurt to check.
I have some other tests I want to run before we start the destructive testing so if there is anything else you would like me to look at, let me know.
The stability of this meter looks pretty good. Thanks for taking the time to do these tests. Have you figured out the reason behind the glitch?
Thank you for that reminder. I will use that when I make the next segment and compare it against the data I collected.We had gone through some simplified battery life tests before and I show the numbers below including the U1282ASorry for the late reply. It's been a long day
....
Thanks for sharing these. The glitch looks similar to what I experienced before on a Keithley 2700. Other than that the drift doesn't look so bad. Definitely better than my Gossen calibrator. Did you connect the resistor directly to the banana socket?
I ran the battery life test tonight and as promised, I tried it in both DCV and resistance modes. With the 40ohm load, I was able to lower the battery voltage until the meter turns off without any change in the measurement. The same was true with a DCV source. I have seen this be a problem before so didn't hurt to check.
I have some other tests I want to run before we start the destructive testing so if there is anything else you would like me to look at, let me know.
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013)
We had gone through some simplified battery life tests before and I show the numbers below including the U1282A
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013)
Trader, the tests we did (joe also did similar tests a few posts before mine) were a linearization of a typical battery behaviour. The simple quotient between a nominal value for the battery capacity (which may vary between brands and models) and the current consumption are more optimistic than a real battery. For example, for the UT61E the cutoff voltage of just 2,3V (which yields the 305h) is unrealistic as the meter wouldn't start at all since it would throw a beep that draws much more current than the battery would be capable of supplying.We had gone through some simplified battery life tests before and I show the numbers below including the U1282A
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013)
Your tests are impressive, I wonder why did you find half of the time informed in the datasheet:
Keysight U1273A: up to 60 hours vs 33.33h
Keysight U1282A: up to 800 hours vs 377.4h
BTW, these OLED DMMs have terrible battery life.
Maybe Keysight overstated the battery life?
Also, it is mechanically quite robust (Dave went through a canyon with it)
Brymen owner's already know how their meters perform but you Keysight fanboys will have to wait. That's a 1mV signal from my Fluke standard.Is this the display or the meter itself? It would be interesting to see if it comes back to life if the temperature is gradually raised back to its specified -20ºC.
This Brymen 869 has no changes, right? Why did they put Operating Temperature "0°C to 45°C" in the datasheet?Although the meter is still working under these conditions, the apparent underspec might be met if the meter is pushed towards its operational range (1kV at CAT III or CAT IV environment).
Dave did not only put it through waterproof tests, but many more:Also, it is mechanically quite robust (Dave went through a canyon with it)
They may be waterproof but are they robust?
This Brymen 869 has no changes, right? Why did they put Operating Temperature "0°C to 45°C" in the datasheet?
I am guessing you are referring to the Keysight LCD where I blanked out the LCD. Don't worry, the next video segment will show it all.Brymen owner's already know how their meters perform but you Keysight fanboys will have to wait. That's a 1mV signal from my Fluke standard.Is this the display or the meter itself? It would be interesting to see if it comes back to life if the temperature is gradually raised back to its specified -20ºC.
Dave did not only put it through waterproof tests, but many more:Very true and watching Dave abuse the meter's mechanically, as a EE was this is partly what started me looking at how robust they were electrically. That and the dataless fanboys.
This Brymen 869 has no changes, right? Why did they put Operating Temperature "0°C to 45°C" in the datasheet?Although the meter is still working under these conditions, the apparent underspec might be met if the meter is pushed towards its operational range (1kV at CAT III or CAT IV environment).
Maybe you could answer why would a viewer call Brymen owner's "pussies" then withdraw it? Maybe you too are looking for a little respect for your expert opinions? :-DD :-DD
This Brymen 869 has no changes, right? Why did they put Operating Temperature "0°C to 45°C" in the datasheet?
OR, there is something else...
Maybe you could answer why would a viewer call Brymen owner's "pussies" then withdraw it? Maybe you too are looking for a little respect for your expert opinions? :-DD :-DD
The only thing I can say is that YOU are Destroying your review with So MUCH BIAS against Keysight and in Favour of Brymen, in fact, Brymen sends free DMMs to you!
I would suggest you try to be less passionate and more impartial, I know that many tricks can be done to make up for a result, remember the "Volkswagen emissions scandal" (aka "Dieselgate", "Emissionsgate")?
I'm not saying this is a "Brymengate", but all your comments expose a hating against Keysight since the beginning, this gives a strong discredit to your review.
BTW: the Keysight U1282A specs says: "-20°C to +55°C", not -40C; and Brymen 869s datasheet says "0°C to 45°C", so I guess they never tested that, just put a conservative value, OR, there is something else...
"Volkswagen emissions scandal" We had an youngster at work who wanted to lecture me about this case. I gave them a history lesson so they wouldn't be so ignorant the next time they approached the topic.
earn[/b] their respect, nothing is given for free.
First, the specs says -20C, not -40C, no reason for criticizing Keysight, in fact I didn't see a picture of -20C.
The Log glitch is small, but relevant, maybe could fixed via software. But it's so clear that could be easily removed from the dataset, as an outlier.
I had 20+ years in automotive before changing careers. Much of our government's involvement is transparent and on-line. Rather than my point of view, try Google."Volkswagen emissions scandal" We had an youngster at work who wanted to lecture me about this case. I gave them a history lesson so they wouldn't be so ignorant the next time they approached the topic.Maybe it's a bit off-topic but I am quite interested to know more about this from your point of view. What is this history lesson you were talking about?
Huh? Logging is usually used to find glitches. How exactly will you distinguish between a momentary power glitch and an "outlier"?
Huh? Logging is usually used to find glitches. How will you distinguish between a momentary power glitch and an "outlier"?
Indeed it is. I wasn't sure if the meter had died or the display had somehow just faded away.I am guessing you are referring to the Keysight LCD where I blanked out the LCD. Don't worry, the next video segment will show it all.Brymen owner's already know how their meters perform but you Keysight fanboys will have to wait. That's a 1mV signal from my Fluke standard.Is this the display or the meter itself? It would be interesting to see if it comes back to life if the temperature is gradually raised back to its specified -20ºC.
Indeed. What you showed with the smaller Keysight's rotary switch (and could potentially repeat in this one) is that a chain is only strongest on its weakest link. The U1282A might survive drops and being run over by cars, but the switch, a PTC or fuse might be its Achilles' heel. What matters for someone might be insignificant for someone else. That is why tests are important.QuoteDave did not only put it through waterproof tests, but many more:Very true and watching Dave abuse the meter's mechanically, as a EE was this is partly what started me looking at how robust they were electrically. That and the dataless fanboys.
I have had the function switches fail which is why I started running that 50,000 full rotation test. This is something I would have expected Dave to do, but it takes time to setup. In the case of that last Keysight meter though, it was all over after a few thousand cycles. There were no more audible clicks coming from my lab as the Keysight went into stealth mode.
That is the reason why I used the words apparent and might. They give the correct measurement of uncertainty that the subject requires, as I don't work for Brymen (nor for one of their testhouses) to be absolutely sure.This Brymen 869 has no changes, right? Why did they put Operating Temperature "0°C to 45°C" in the datasheet?Although the meter is still working under these conditions, the apparent underspec might be met if the meter is pushed towards its operational range (1kV at CAT III or CAT IV environment).
That's 100% speculation.
(and also contains an unfounded insinuation that a Keysight wouldn't do that even though it has a lower CAT rating than the Brymen)I can't make any assessment on what you read between the lines, Fungus. Give it a rest and don't assume I am a Keysight fanboy.
So, I am the one speculating, huh?This Brymen 869 has no changes, right? Why did they put Operating Temperature "0°C to 45°C" in the datasheet?
The obvious answer is that their specs are conservative and leave some margin. I'm not aware of any tests where Brymen meters have underperformed.
Working on the editing tonight and took a screen shot of your data. When I compared the nominal with what I collected, we were very close.Thank you for that reminder. I will use that when I make the next segment and compare it against the data I collected.We had gone through some simplified battery life tests before and I show the numbers below including the U1282ASorry for the late reply. It's been a long day
....
Thanks for sharing these. The glitch looks similar to what I experienced before on a Keithley 2700. Other than that the drift doesn't look so bad. Definitely better than my Gossen calibrator. Did you connect the resistor directly to the banana socket?
I ran the battery life test tonight and as promised, I tried it in both DCV and resistance modes. With the 40ohm load, I was able to lower the battery voltage until the meter turns off without any change in the measurement. The same was true with a DCV source. I have seen this be a problem before so didn't hurt to check.
I have some other tests I want to run before we start the destructive testing so if there is anything else you would like me to look at, let me know.
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013)
Just a quick erase with Paint. The results were actually very surprising if you haven't looked at yours. About 4 hours of testing boils down to 6 minutes of video.Indeed it is. I wasn't sure if the meter had died or the display had somehow just faded away.I am guessing you are referring to the Keysight LCD where I blanked out the LCD. Don't worry, the next video segment will show it all.Brymen owner's already know how their meters perform but you Keysight fanboys will have to wait. That's a 1mV signal from my Fluke standard.Is this the display or the meter itself? It would be interesting to see if it comes back to life if the temperature is gradually raised back to its specified -20ºC.
The concerning thing for me is as Fungus has mentioned, the performance does not match the specifications in at least two areas, and the strange thing is it's in things most people couldn't care less about.
...
I care that they chose to claim better performance than they deliver; it's out of character for a premium brand, but fits with the corporate bean counter culture that seems to have ousted the engineering culture at HPAK.
The concerning thing for me is as Fungus has mentioned, the performance does not match the specifications in at least two areas, and the strange thing is it's in things most people couldn't care less about.
We had gone through some simplified battery life tests before and I show the numbers below including the U1282ACould you please go back and retest your MaxFunc readings? I measured higher back light current than you show which I guess isn't too big of a surprise but I wonder what you did to get the MaxFunc up to 7.1mA?
Joe, I can do this later. Regarding the MaxFunc, there might be a chance I was trying with a mode other than continuity (I was fishing for the highest consumption regardless of the mode).We had gone through some simplified battery life tests before and I show the numbers below including the U1282ACould you please go back and retest your MaxFunc readings? I measured higher back light current than you show which I guess isn't too big of a surprise but I wonder what you did to get the MaxFunc up to 7.1mA?
When I have taken this data, its always without the leads attached. Did you have a load attached? I just tried it with my other equipment and repeated what I see with my source meter that I normally use. Everything repeats. I then tried it with a short in continuity mode with the beeper full on and still could not reach 7.1mA. It could be the two meters are just that different and maybe they tried to improve the battery life. I just want to make sure I didn't miss something.
The concerning thing for me is as Fungus has mentioned, the performance does not match the specifications in at least two areas, and the strange thing is it's in things most people couldn't care less about.
I think a lot of people care about battery life. It was one of the mentioned when I asked why people would buy this meter.
Keysight also seems to think it's important: It's number three on the "key features" list in the brochure (right after counts and DC accuracy) and it gets the very first paragraph in the blurb.
See page 2 of this: https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf (https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf)
Prolonged battery life and rugged
"The last thing you want is for your tools to run out of juice when you need it the most. The U1280 series
handheld DMMs lets you carry out test and measurements over a longer duration than ever before. With
up to 800 hours of battery life, you have a handheld DMM which works for a long time minus the hassle of
battery change, especially useful for frequent usage or prolong testing. Put your battery concerns behind
and fully focus on your work at hand, as it should be for maximum productivity."
(I guess they do say "up to". Maybe you can do it with fancy lithium batteries or something... ::) )
:-DD Yes, I know -40 is the crossover. It's also what I used to design for.
Looks like it may have been diode check with a short to enable the beeper. This gets me very close so I think we are all set.Joe, I can do this later. Regarding the MaxFunc, there might be a chance I was trying with a mode other than continuity (I was fishing for the highest consumption regardless of the mode).We had gone through some simplified battery life tests before and I show the numbers below including the U1282ACould you please go back and retest your MaxFunc readings? I measured higher back light current than you show which I guess isn't too big of a surprise but I wonder what you did to get the MaxFunc up to 7.1mA?
When I have taken this data, its always without the leads attached. Did you have a load attached? I just tried it with my other equipment and repeated what I see with my source meter that I normally use. Everything repeats. I then tried it with a short in continuity mode with the beeper full on and still could not reach 7.1mA. It could be the two meters are just that different and maybe they tried to improve the battery life. I just want to make sure I didn't miss something.
The capacitance mode comes to mind, but I can't be sure at the moment.
With the timing, I still think it's damage control. :-DD
With the timing, I still think it's damage control. :-DD
I actually approached Daniel about 3 or 4 months ago about doing a multimeter review, I had to wait a while before it could be sent due to component shortages.
I don't understand the point of testing these meters beyond their specifications. It says right on the front of the Keysight: "1000v" with CAT IV; why go beyond this?
These test are irrelevant over what is rated, is like you smash a car at 2 mach and say "ehh car not good, unsafe, bla bla" whats the point of using a meter over the rated point???
Why did you treat the Keysight unfairly?
Some Batteries (material/brands) stop working in low temperatures.
I don't understand the point of testing these meters beyond their specifications. It says right on the front of the Keysight: "1000v" with CAT IV; why go beyond this?
These test are irrelevant over what is rated, is like you smash a car at 2 mach and say "ehh car not good, unsafe, bla bla" whats the point of using a meter over the rated point???
Why did you treat the Keysight unfairly?
I read this as a challenge that you need to up your transient tester to actually be able to output 6000A at 12KV with a 2Ohm source impedence. :box:
I mean the last thing you want to do is treat the Keysight unfairly and not to it's rated spec. :-DD
Look closer though: The reason there's no display on the Keysight at -40C is that joe blanked it out using Windows Paint to keep us in suspense.
All the "-40C" image shows is that the Brymens are still working, it doesn't say anything about the Keysight.
I don't think Fungus's poor little Fluke 101 was spec'ed to handle that. Funny that meter has never been damaged and I don't think I have had it apart.
Then to have another member step up and repeat that 12kV test just to see if I was BSing, using an actual IEC generator from their work place was a pleasure to watch. Now that's how you review a meter!! :-DD
You don't happen to have a link to that video do you? I'm very interested in watching!
...poor little Fluke 101. Funny that meter has never been damaged and I don't think I have had it apart.
You don't happen to have a link to that video do you? I'm very interested in watching!
Go to the first page where I created a TOC to help members navigate this thread. Then find: "Member Meter Junkie runs a second Fluke 101 on their IEC combo generator at 12KV"
He mentions it was suggested it should survive 17. I ran that Fluke 107 to I think 15 before it finally gave in. Even then it was hardly a scratch. Think this Keysight will handle that? :-DD :-DD
I've had mine apart. It has some big, chunky components inside.They just look big and chunky because the meter is so small this it fits in your shirt pocket.
...
Not bad for a $45 meter.
...
Found it but it looks like access to the video has been limited. O well, it sounds like it was pretty boring :-DDThat's too bad they set it to private. The did post a few comments close to that link, or you could search the name in this thread to find out more about it. I believe this was photo they sent of their generator that was used to test the 101.
I hope the keysight survives. If only because I want to believe that they live up to their heritage!
:-DD
I would hate the Keysight fanboys to think their meter turned off because of crap batteries so here's a better view of the U1282A...
:-DD
I would hate the Keysight fanboys to think their meter turned off because of crap batteries so here's a better view of the U1282A...
Is easy to see when someone is totally biased.
You can't ask anything, or you will be a "fanboy", and all the answers are to criticize the questioner and disrespect the feedback.
But this is the standard behavior in this forum, nothing new here.
While I think some of his testing being is not always directly useful, except for entertrainment, one thing I do value him for is irreverence and following facts where they take him. And he honestly documents data as it is, good and bad...
Can I say in reference to this BS, respect is earned not given as a right.
But, since I know very well the Total Lack of Respect from the majority of people here... no hope.
Maybe as a newbie here you are yet to learn this ? :-//
-40 degrees, 50K rotations, 100ft dropping, 14K transients, etc... seems like an ElectroBoom review, just for fun. Almost zero probability of this use. (I won't ever use it above 1000V (or even 400V), and if this happens will be 15K, 30K, or 100K? doesn't matter, this is Very Far from the Max Specs).
I'm not a fanboy, YOU and he are hatters of people that express divergent opinions.
While I think some of his testing being is not always directly useful, except for entertrainment, one thing I do value him for is irreverence and following facts where they take him. And he honestly documents data as it is, good and bad...
At least you agree how useless is to use a "crappy box" with a lot of uncalibrated "references" that even an HB DMM will do very good, put it in a refrigerator below the specs without confirming batteries specs, and the best part, do 50K knob rotations, LOL :-DD.
I'm not a fanboy, YOU and he are hatters of people that express divergent opinions.
Actually, these are the same people that prefer to Destroy a DMM by dropping it from a dam, just for "entertainment".
MY (understand this word: "MY", ok?) opinion is that the TheDefpom 2-videos review was much more useful, to verify if all the specs are very accurate (much better than that crappy box), and did you read that "With the timing, I still think it's damage control", a big shame... :palm:
-40 degrees, 50K rotations, 100ft dropping, 14K transients, etc... seems like an ElectroBoom review, just for fun. Almost zero probability of this use. (I won't ever use it above 1000V (or even 400V), and if this happens will be 15K, 30K, or 100K? doesn't matter, this is Very Far from the Max Specs).
The LOG issue was a useful discovery, interesting nobody realized that in 7 years (people were more concerned about dropping it from a waterfall), anyway, I hope KS checks/fix that.
Remember, this is "MY" option, and I don't care what you think about other people's opinions, if you don't agree, you are free to express YOUR OWN opinion since don't criticize other people's opinions.
But, since I know very well the Total Lack of Respect from the majority of people here... no hope.
I wasn't aware that Joe was testing the meter for your personal gratification. :-//
Your "opinion" was: "U1282A 4-batteries last more than 1000 hours".
I wasn't aware that Joe was testing the meter for your personal gratification. :-//
Me neither, what's your point? Can't I be free to like or dislike? Or have free speech for feedback?Your "opinion" was: "U1282A 4-batteries last more than 1000 hours".
The manual says "800 hours typical based on new alkaline batteries for DC Voltage measurement".
I was very clear, this is an Opinion Based on Empirical Observation! I never demanded fixing that "battery life table"!!!
Maybe the new firmware could consume more power, or the settings, readings per second, etc; but I'm sure that I use it Much More than 377.4h hours (informed on that table) and the batteries still like full, even after being installed 6-years ago!!!
First and foremost, I don't agree anything with you..
Defpom videos where he checks "accuracy" of reading have (to me) same merit as Joes "plastic"box, unless his calibrators are kept in current calibration with traceable calibration facility.
You are free to express your opinions. Please don't attack people that don't agree with you. Accept that in same way as you have freedom to express anything you like, you shouldn't be rude to people
and in addition to that , these other people have freedom to call bullshit, laugh if you say something stupid or similar.
If you said something stupid or malicious, they have freedom to call you out on it. It doesn't mean they have right to insult you explicitly.
DCV measurement puts the least demand on the batteries; the AC TRMS converter is inactive, there is no current being used to measure resistance or diode junction drop, and no ramp is generated to charge a capacitor. It verges on the disingenuous to categorise a use profile that is exclusively DCV as "typical".
Hum... I guess I understand, is like: "no personal attacks, but just bullying, moral offenses, and implicitly insults", right? Thanks for clarifying. :-DD:-//
Everyone must be given benefit of the doubt. Respect is earned. You claim you respect everybody but many of your posts here are quite the opposite of that.
You can have 10 voltmeters all showing precisely 10.0000V and all of them wrongly adjusted to same wrong 9.9V calibrator. If proper procedures are not followed it is not calibration.
Will we see history once again repeat itself?? :-DD I have changed the brand name for your viewing pleasure.Have you never used a tool beyond what it's rated to do knowing you are putting it at risk ?
When I first listened to the video you came across as strongly anti Keysight so that appears to make you biased against the company straight away. Every multimeter has to be treated independently so it does not depend on the series or company it is from. You have said this yourself! There is a danger that you will stereotype a company because it does not at first live up to your own standards. "Saving your skin" is just saying that viewers will treat you with more respect and not pass you off as an anti Keysight tester.
I don't understand the point of testing these meters beyond their specifications. It says right on the front of the Keysight: "1000v" with CAT IV; why go beyond this?
These test are irrelevant over what is rated, is like you smash a car at 2 mach and say "ehh car not good, unsafe, bla bla" whats the point of using a meter over the rated point???
Why did you treat the Keysight unfairly?
Will we see history once again repeat itself?? :-DD I have changed the brand name for your viewing pleasure.Have you never used a tool beyond what it's rated to do knowing you are putting it at risk ?
When I first listened to the video you came across as strongly anti Keysight so that appears to make you biased against the company straight away. Every multimeter has to be treated independently so it does not depend on the series or company it is from. You have said this yourself! There is a danger that you will stereotype a company because it does not at first live up to your own standards. "Saving your skin" is just saying that viewers will treat you with more respect and not pass you off as an anti Keysight tester.
I don't understand the point of testing these meters beyond their specifications. It says right on the front of the Keysight: "1000v" with CAT IV; why go beyond this?
These test are irrelevant over what is rated, is like you smash a car at 2 mach and say "ehh car not good, unsafe, bla bla" whats the point of using a meter over the rated point???
Why did you treat the Keysight unfairly?
TBH we all have and I see no issue with Defpom testing/investigating if an instrument can be used beyond any of its ratings for the benefit both his and our knowledge.
There are times when we might only have a particular tool available so to know it can handle work beyond its ratings as member bd139 discovered his little Bymen BM22s could do when he needed to set the EHT on a CRO.
Shocking abuse of a DMM I know but after some trouble to find it I'll leave this here:
Defpom videos where he checks "accuracy" of reading have (to me) same merit as Joes "plastic"box, unless his calibrators are kept in current calibration with traceable calibration facility. They are both homemade quick sanity check of basic functionality. Joe is clear and open about that. It is you who didn't listen, chose to ignore, or deliberately lie about his intentions.
Joe is having his fun, with his own money and on his own time..
You either watch or not, agree or not...
While I think some of his testing being is not always directly useful, except for entertrainment, one thing I do value him for is irreverence and following facts where they take him. And he honestly documents data as it is, good and bad...
re subjective opinion (on topic)My subjective ranking is the following:
I might be in a small minority here, but Keysight's rotary switch (on my U1242C) feels fine to me. And although I like Gossen, Fluke, and AVO well enough I find on the Keysight you're less likely to overshoot when turning it to each position. :-+
1. The absolute kings: Fluke 87V and 179
Hehehe... They are too rich for me. I wasn't as lucky as you to get one on the cheap. :clap:1. The absolute kings: Fluke 87V and 179
LOL, just try a Gossen ;)
Anyone notice a new Brymen clamp meter, the BM037 that Dave apparently will market ?
We think you should put it through its paces Joe. :popcorn:
:-DDAnyone notice a new Brymen clamp meter, the BM037 that Dave apparently will market ?
We think you should put it through its paces Joe. :popcorn:
We? You and Dave?
Searching you will find it mentioned in 2020 so it's not a new product:Yes, wonderful bits of kit these old current probes and have had a P6021 for some years and added the 120MHz P6022 to my kit a year or 2 back.
https://www.eevblog.com/forum/testgear/clamp-meter-safe-reliable-and-under- (https://www.eevblog.com/forum/testgear/clamp-meter-safe-reliable-and-under-)$200/
More info is here:
https://brymen.eu/shop/bm037/ (https://brymen.eu/shop/bm037/)
https://brymen.eu/wp-content/uploads/biall/102194/102194.INSTRUKCJA_EN..2019-02-26.1.pdf (https://brymen.eu/wp-content/uploads/biall/102194/102194.INSTRUKCJA_EN..2019-02-26.1.pdf)
I have never transient tested a clamp meter. Not being an electrician, it's not something I would have much use for. I suspect the lack of interest suggests other hobbyist also have little interest in them. For automotive, I normally need something much more sensitive to detect high leakage currents. On the bench, I would typically want something with much higher BW. I like that old 1960's Tektronix P6042.
Guessing if Dave plans to sell it, he will make a review. You may want to suggest tests for him to run.:-DD
:-DD
And put the fox in charge of the hen house, not bloody likely !
I did go back and look at that little pocket Brymen I had left outside and beat the crap out of. Mine over ranges at 600V.
My P6042 was a trash pick in VERY poor condition. It took a few weeks to repair it. Sorting bags of transistors looking for matched sets. I was able to get the bandwidth up to about 100MHz with it. Impressive for the age of the thing.They certainly are however I only have the 60 & 120 MHz passive AC current probes with their BNC terminations and also picked up a Type 134 amplifier for them....just to have really as the passive terminations are far more convenient.
I think I once caught one of Dave's live streams maybe for the 121. I never see any notices about them. I'm skipping around it now. Is there something specific you would like me to watch or just in general?;)
While I think some of his testing being is not always directly useful, except for entertrainment, one thing I do value him for is irreverence and following facts where they take him. And he honestly documents data as it is, good and bad...
-40 degrees, 50K rotations, 100ft dropping, 14K transients, etc... seems like an ElectroBoom review, just for fun. Almost zero probability of this use. (I won't ever use it above 1000V (or even 400V), and if this happens will be 15K, 30K, or 100K? doesn't matter, this is Very Far from the Max Specs).
It is not merely a matter of the rated voltage 1kV you use and test your meter. If a meter is claimed to be rated to CAT IV 1kV meeting the IEC 61010 series in its user's manual, for example, it has to survive the IEC transient test requirement of 12kV from a hybrid impulse generator with a source impedance of 2 Ohms. It is a 1.2/50uS OCV + 8/20uS SCC combo waveform capable of delivering 6000A peak currents. It resembles the magnitude of transients at the source of the building's MAINS. If the meter failed the test, it failed the manual specs it claimed IMHO. :phew:
(...)I think the meter might be alright as well with protection well above your average chinese product, but the fact the rotary switch is in the center and not on the side is a big limiting factor for the main audience of clamp meters (electricians). AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways). The one detracting factor I noticed was indeed the battery access - the threaded screws are a huge turnoff, especially for electricians that will put it to more use, since they don't carry two instruments to a job but only one that does everything.
Ok, that's the end. I gave the video a thumbs up. Meter seems alright but isn't something I would have a use for.
(...)I think the meter might be alright as well with protection well above your average chinese product, but the fact the rotary switch is in the center and not on the side is a big limiting factor for the main audience of clamp meters (electricians). AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways). The one detracting factor I noticed was indeed the battery access - the threaded screws are a huge turnoff, especially for electricians that will put it to more use, since they don't carry two instruments to a job but only one that does everything.
Ok, that's the end. I gave the video a thumbs up. Meter seems alright but isn't something I would have a use for.
I would get one if it is priced competitively, but the UT210E is indeed hard to beat for the electronics hobbyist.
AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).
That is pretty neat indeed and I can see its practical aspects. :-+AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).
I have an Ideal branded clamp meter (Pretty sure it's actually a Uni-T :-DD). And they have this really neat dual display. I was expecting it to be gimmicky, but I have used the display on the end of the meter often.
That is pretty neat indeed and I can see its practical aspects. :-+AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).
I have an Ideal branded clamp meter (Pretty sure it's actually a Uni-T :-DD). And they have this really neat dual display. I was expecting it to be gimmicky, but I have used the display on the end of the meter often.
Although I wonder if it weakens the housing.
I tried to find the OEM but to no avail. I tried CEM, Mastech, Uni-T and Appa.
Looks like they used two 5mm PTCs in series rather than adding the surge rated resistors we commonly see.
LOL, frozen KS !
Would you like ketchup with that Sir ? :-DD
That Keysight U1231A was damaged beyond repair at 5kV 100us FWHH 2 ohm source. The same level that sent the UNI-T UT139C to the recycle bin. What level will take out the U1282A? Add your vote.
***
I like when things repeat and expect it to fail at the same level the previous Keysight was damaged at.
Considering that none of what I show follows IEC standards or has anything to do with the CAT ratings of the meters, seems like as good a guess as any. The waveform from the newer generator has a 100us FWHH and only about 20J so the current will roll off fairly fast by comparison. If it makes it to the higher voltage generator, that uses a 50us FWHH and is even lower energy. Still.... how much energy does it take to damage a SOT23?That Keysight U1231A was damaged beyond repair at 5kV 100us FWHH 2 ohm source. The same level that sent the UNI-T UT139C to the recycle bin. What level will take out the U1282A? Add your vote.
***
I like when things repeat and expect it to fail at the same level the previous Keysight was damaged at.
Since the 1231 failed near the CATIII600 6k transient its rated for I expect the 1282 to be near it's CATIV600v rating of 8k.
That Keysight U1231A was damaged beyond repair at 5kV 100us FWHH 2 ohm source. The same level that sent the UNI-T UT139C to the recycle bin. What level will take out the U1282A? Add your vote.Well if it fails we know why:
***
I like when things repeat and expect it to fail at the same level the previous Keysight was damaged at.
What about some lighter solvents like IPA? I don't often use racing fuel on my bench but the IPA comes out quite often.I doubt I will add any others to the test but you are certainly free to run your own tests with what ever cocktail you can come up with. Please post the results if you do.
Then there's the acetone ... I try not to use that one the bench though. :scared:
I expect acetone would make a mess of just about any meter but these are supposed to be tough and "industrial". Maybe try it on some of the less important lettering. :popcorn:
Non-destructive testing of the Keysight U1282A.Great testing, Joe! I only wish you had put in the chamber the meter with the same Hycon chipset to see if we could further isolate the root cause of the issue down to the processor/chipset itself (my best bet, since the meter became "frozen") or another component (XTAL, voltage regulator, etc.). From where we see, there is a chance that Brymen's chipset might be better fabricated than Hycon, but we can only speculate.
Thanks for sharing the pictures; indeed the bottom display seems sturdy.That is pretty neat indeed and I can see its practical aspects. :-+AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).
I have an Ideal branded clamp meter (Pretty sure it's actually a Uni-T :-DD). And they have this really neat dual display. I was expecting it to be gimmicky, but I have used the display on the end of the meter often.
Although I wonder if it weakens the housing.
I tried to find the OEM but to no avail. I tried CEM, Mastech, Uni-T and Appa.
It looks like they did the housing pretty well. There is additional plastic ribbing to reinforce the display and input jacks.
I can't say for sure who the OEM is, but the interior build looks suspiciously similar to my Uni-T 210e. It appears to be (the scratched off the label) the same DM1106 controller chip. If they weren't made by the same OEM, they appear to have been based off the same reference design.
Great testing, Joe! I only wish you had put in the chamber the meter with the same Hycon chipset to see if we could further isolate the root cause of the issue down to the processor/chipset itself (my best bet, since the meter became "frozen") or another component (XTAL, voltage regulator, etc.). From where we see, there is a chance that Brymen's chipset might be better fabricated than Hycon, but we can only speculate.
Thanks for sharing the pictures; indeed the bottom display seems sturdy.That is pretty neat indeed and I can see its practical aspects. :-+AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).
I have an Ideal branded clamp meter (Pretty sure it's actually a Uni-T :-DD). And they have this really neat dual display. I was expecting it to be gimmicky, but I have used the display on the end of the meter often.
Although I wonder if it weakens the housing.
I tried to find the OEM but to no avail. I tried CEM, Mastech, Uni-T and Appa.
It looks like they did the housing pretty well. There is additional plastic ribbing to reinforce the display and input jacks.
I can't say for sure who the OEM is, but the interior build looks suspiciously similar to my Uni-T 210e. It appears to be (the scratched off the label) the same DM1106 controller chip. If they weren't made by the same OEM, they appear to have been based off the same reference design.
Looking at the PCB silk screen, it seems to me an original design from Ideal: the model number 61-757 is shown in both PCBs. :-+
Non-destructive testing of the Keysight U1282A.Great testing, Joe! I only wish you had put in the chamber the meter with the same Hycon chipset to see if we could further isolate the root cause of the issue down to the processor/chipset itself (my best bet, since the meter became "frozen") or another component (XTAL, voltage regulator, etc.). From where we see, there is a chance that Brymen's chipset might be better fabricated than Hycon, but we can only speculate.
Another aspect: when you rotated the switch after the low temp tests, was the meter already back at a specified temperature of at least -20ºC?
The reason is that the material might have become brittle at such low temperature and rotating it might degrade it (microfissures?) which would add another variable to the rotary switch tests.
Great testing, Joe! I only wish you had put in the chamber the meter with the same Hycon chipset to see if we could further isolate the root cause of the issue down to the processor/chipset itself (my best bet, since the meter became "frozen") or another component (XTAL, voltage regulator, etc.). From where we see, there is a chance that Brymen's chipset might be better fabricated than Hycon, but we can only speculate.
May I suggest comparing the Hycon chip datasheet/pinout with the "custom" chipset in the BM789. :popcorn:
Great testing, Joe! I only wish you had put in the chamber the meter with the same Hycon chipset to see if we could further isolate the root cause of the issue down to the processor/chipset itself (my best bet, since the meter became "frozen") or another component (XTAL, voltage regulator, etc.). From where we see, there is a chance that Brymen's chipset might be better fabricated than Hycon, but we can only speculate.
May I suggest comparing the Hycon chip datasheet/pinout with the "custom" chipset in the BM789. :popcorn:
I'll leave the reverse engineering to others. It's certainly something you could do. Anytime I have dove into a design, it was to get some idea why a meter failed my tests or how to improve it.
Pretty cool tests, seems to be a very robust DMM.If you were confused about how "...useless is to use a "crappy box" with a lot of uncalibrated "references"..", chances are good that there are others who are also not understanding what is being shown. While the threads now several years old and the basics are documented and have been explained many times, I certainly understand not everyone is going to take the time to do any research before chiming in with their expert opinion.
Thanks for explaining about the testing box.
I don't think the testing box is "useless", yes you are using it just to know if the meter still working; but I'm sure that could be much better if you at least provide a table with the "correct" value of each reference, maybe the meter could be a little off after the tests.
I know, nothing there is accurate and can vary a little when the temperature or power supply changes, but at least is better than not knowing the correct value.
Again, I assume the meters are within their manufactures specs when I buy them. Had my goal been to verify their calibration, I would rent a calibrator. That said, this does seem to be Defpom's area of interest. Mine is how robust these meters are.
I would have liked to ran the Keysight open fused at 2kV like the standard calls for and just see what happens. It's not been a problem but this is the first time I have seen a meter load my supply like this.
Wait... It looks like your Applied KilloVolts power supply is capable of 40ma. That would imply that the 1282A is dissipating about 80W somewhere. :wtf:
For comparison the BM78x uses a of 5MOhm resistor per amp jack for the lead sense which if my math is correct it would be expected that the current draw with 2KV applied would be around 0.4ma and Brymen used 2W resistors to handle the power (expected 0.8W) dissipated. That's a significant difference between the different meters.
Did you run this test on the BM78x meters? I don't remember seeing it in any of the videos.
Wait... It looks like your Applied KilloVolts power supply is capable of 40ma. That would imply that the 1282A is dissipating about 80W somewhere. :wtf:
To save you time searching.
Chemical: 21:44
Open Fuse: 22:55
Finally, the meter is damaged at 12kV (more than double what my first Keysight was damaged at): 57:47
After 50,000 full rotations on the switch: 1:15:00
https://www.youtube.com/watch?v=UY9Myo5ngPQ (https://www.youtube.com/watch?v=UY9Myo5ngPQ)
Attached showing the last time I checked my UT61E, representing almost 6 years of data. Of course, this meter is highly modified for educational purposes only.
It's.too bad the Uni-T aren't very robust. They seem like great measuring meters and certainly fall under the bang for buck category. If they made them just a bit more robustly they could be great meters! I really wonder how muchlre it would cost them to make them just a bit better. It seems they are willing to spend money on parts in their better meters.
Thanks for the link. I probably don't remember that test because it.was too uneventful. :-DDIt's possible that because both the BM786&9 were still in the development stages (not yet available for purchase) that I spent more time going over them both. It's rare we get to look at preproduction products and have an opportunity to provide a company feedback that could be used to possibly release a better product. Dave had shown us the meter long before I became involved. I guessing he was testing them and uncovering a few problems as well.
I honestly think that poor meter got the most scrutiny of any of your videos I watched. It certainly says something when a meter takes that much poking and proding and comes out that good. It certainly seems the Flukes and Brymens are in a special league with little company!
It's.too bad the Uni-T aren't very robust. They seem like great measuring meters
This is the difference Brymen brings. Brymen has proven they are interested in producing a good product.
Wait... It looks like your Applied KilloVolts power supply is capable of 40ma. That would imply that the 1282A is dissipating about 80W somewhere. :wtf:
Yep. This needs investigating... where is all that power going?
Does it do it with the switch in the "off" position?
Edit: I guess it survived though, and an 8kV transient is only going to push something like 200mA through it for an instant, it will probably survive that, too. :-//
OTOH it doesn't inspire confidence. It doesn't say "we made it as good as possible!", it asks "where else did they cut corners?"
I did not try this test in the off position, only in the Amps range that was being tested at that time.
Looks like I could borrow a supply what would get us to 150mA. The standard calls for 500VA but it may be enough to damage the meter. I think the first step is to trace this section out and see what these top Keysight engineers have done to cause such a high load.
I did not try this test in the off position, only in the Amps range that was being tested at that time.
Looks like I could borrow a supply what would get us to 150mA. The standard calls for 500VA but it may be enough to damage the meter. I think the first step is to trace this section out and see what these top Keysight engineers have done to cause such a high load.
You high voltage supply must be very weak, I had expected the meter to start smoking (There is nothing in the meter that can handle more than a few Watt for much time).
Such a difference in how we tested it.
Why ?Such a difference in how we tested it.
Doesn't it deserve to dropped off the roof like the others?
I would like to run the life test on the switch before doing anything else. The question now is do all the prongs on the detent spring crack like before?Such a difference in how we tested it.Doesn't it deserve to dropped off the roof like the others?
I would like to run the life test on the switch before doing anything else. The question now is do all the prongs on the detent spring crack like before?
I suspect the same but that's why we test them.I would like to run the life test on the switch before doing anything else. The question now is do all the prongs on the detent spring crack like before?
Of course... :popcorn:
I suspect the same but that's why we test them.
On the bright side: It might be a short test... :-DMM
Not much to say beyond she's dead Joe.
https://www.youtube.com/watch?v=MEfUDnKJ4z0 (https://www.youtube.com/watch?v=MEfUDnKJ4z0)
Failing in the 5KV Transient Voltage test, means that this DMM is CAT IV for up 150V, but CAT III for 151-300V ?
The CAT documents only say that meters must protect the user. They don't say that the meter has to survive.History once again repeats. Again, the thread is not about meeting a safety standard. Of course it does keep coming up. The question I have for you is if you finally took the time to speak with someone who may actually have the background needed to answer this? Or it is just the same old posting your feelings about a papers I doubt you have ever seen let alone read? Welcome to the internet.
OTOH a meter that survives seems more desirable to me.
:-BROKE :( :'(I asked him about it years ago as a parts meter to repair the prototype 121GW. No luck. Too bad really as it could have very well saved this meter from the recycle bins.
I think it may have been mentioned already, but perhaps you could ask Dave what he did with the U1282A he took down the canyon and if he would be willing to post you the board.
It would be nice to see the rotary selector test done with a fully operational meter to monitor it for any weird stuff during the cycle testing. With the types of testing I use these meters for I am probably more likely to wear out the selector switch well before being anywhere near a 5kV transient.
Well that's disappointing. I was hoping it would do better than that.
One thing that (too late now...) would have been interesting to know is if it was damaged in that hit when the meter shut off, or if the final hit after it turned off is what did the actual damage. What I wonder is if the fact that the DMM chipset would have (likely) been turned off for that last hit, thus taking the range resistors out of circuit, did the meter get damaged worse that it would have if the chipset was still powered? Again it should have survived, but that last hit was (in my opinion) a little unfair due to the fact that no-one would be trying to measure with a meter when it is so obviously in a non-functional state with the display off.
One thing that (too late now...) would have been interesting to know is if it was damaged in that hit when the meter shut off, or if the final hit after it turned off is what did the actual damage. What I wonder is if the fact that the DMM chipset would have (likely) been turned off for that last hit, thus taking the range resistors out of circuit, did the meter get damaged worse that it would have if the chipset was still powered? Again it should have survived, but that last hit was (in my opinion) a little unfair due to the fact that no-one would be trying to measure with a meter when it is so obviously in a non-functional state with the display off.
:-DD I would imagine there are many people who feel several of the tests I conduct are a little unfair!! After a few years, I'm sure I've heard it all. I do wonder at times if making these results public has had any impact on the companies who develop these meters or the people who buy their products.
I am looking for what level the meters are damaged. Just that simple. Because the transient generator is semi-automatic, I will typically walk away from it. If you were to watch where I have damaged other meters, I suspect you will note several cases where the meters are subjected to the full 5 cycles no mater the outcome of each individual transient. I dare say that in some cases I will even go so far as to finish up the remaining transients for a given level. If it's damaged, its damaged. If I roast it to a crisp or pop a SOT23, what is recorded is still the same, the meter failed at level X.
The CAT documents only say that meters must protect the user. They don't say that the meter has to survive.History once again repeats. Again, the thread is not about meeting a safety standard. Of course it does keep coming up. The question I have for you is if you finally took the time to speak with someone who may actually have the background needed to answer this? Or it is just the same old posting your feelings about a papers I doubt you have ever seen let alone read? Welcome to the internet.
OTOH a meter that survives seems more desirable to me.
I have no read the specs
I do remember Joe showing snippets of the standard and one thing that stands out in my memory is the statement that "the meter shall remain capable of indicating hazardous voltage".
This meter certainly was not capable of indicating hazardous voltage after it failed.
Automating the knob rotation for each meter, IMO would be a lot of work with no value added. Designing a generator that supports both polarities vs swapping the leads, again, I see as little value. Of course, if we are going to switch out the generator and then automatically test the meters between each level, again a bit of work for what I see as no value added.Quote from: joeqsmith link=topic=48998.msg4387375#msg4387375... Because the transient generator is semi-automatic, I will typically walk away from it. ...My curiosity not withstanding, running fully automated is the best way to ensure a consistent test across all meters!
...
Joe one thing that seems to hold true is the meters usually fail on the inputs other than the primary voltage input, usually ohms or (as in this case) mv inputs. How is the specification worded regards those inputs? I know it must take the full input voltage, but does it explicitly state that these secondary (ohms mv, etc) inputs must also be able to survive the same transient testing?
Again I know your testing isn't to test the CAT rating. I am just always amazed when NRTL tested meters fail your robustness tests at voltages lower than the CAT transient tests.
I wouldn't mind seeing someone procure an actual combo generator that also supports modes like burst.
I wouldn't mind seeing someone procure an actual combo generator that also supports modes like burst.
May I ask what a combo generator is? I've googled it and diesel generators showed up. How are diesel generators going to fit into these tests?
I wouldn't mind seeing someone procure an actual combo generator that also supports modes like burst.
May I ask what a combo generator is? I've googled it and diesel generators showed up. How are diesel generators going to fit into these tests?
I was referring to burst and surge transients from the safety standards that people are talking about. Have a look:
https://www.ametek-cts.com/products/productgroups/transient-generators-surge-and-burst/surge-generator (https://www.ametek-cts.com/products/productgroups/transient-generators-surge-and-burst/surge-generator)
Is it similar to a pulse generator like this one:
...
Joe one thing that seems to hold true is the meters usually fail on the inputs other than the primary voltage input, usually ohms or (as in this case) mv inputs. How is the specification worded regards those inputs? I know it must take the full input voltage, but does it explicitly state that these secondary (ohms mv, etc) inputs must also be able to survive the same transient testing?
I'm pretty sure I went over this early on but you would need to read them to know for sure. I can tell you in Joe's world, they are going to be tested this way before I will ever consider them robust.Again I know your testing isn't to test the CAT rating. I am just always amazed when NRTL tested meters fail your robustness tests at voltages lower than the CAT transient tests.
I am amazed when meters are damaged by that stupid little grill starter or if they fail at levels lower than what damaged that $50 Amprobe AM510. The worse, IMO, are meters like this Keysight that carry a high price tag an are rendered non-repairable.
I am mostly curious if the standard omits the transient tests for inputs like ohms
as a way to explain how a high end meter like the keysight could pass third party testing, but still fail at your less demanding tests.
I am mostly curious if the standard omits the transient tests for inputs like ohms
I believe it specifically includes them, that meters have to "fail safely" with all possible combinations of selector switch and input jack.
as a way to explain how a high end meter like the keysight could pass third party testing, but still fail at your less demanding tests.
CAT rating is a safety rating. If the user was in no danger then it's a pass!*
Is there a hard requirement in the standard to indicate unsafe voltages or is is the requirement something more like "never show lower voltages than are actually present"? A blank screen would meet that requirement - if it's not showing you any voltages at all then it's not telling you any lies.
(*) I'm not an expert, I haven't read the standard, this is just my understanding from reading Internet forums. I love being corrected.
CAT rating is a safety rating. If the user was in no danger then it's a pass!*Again, how do you know that the user would not be in danger? How do you know that the meter would not fail catastrophically if there was sufficient energy behind the pulse?
I would NOT be comfortable using a meter that can breakdown internally at half its rating if I were working in an arc flash environment.
Again, are you really able to extrapolate safety from Joe's tests?
...This is not correct.
All we know from Joe's testing is that an ESD event with a 5KV or greater potential can irreparably damage the meter.
...
That's why I am curious about how the standards are worded, and I thought you had a copy (I do not have access to a copy) which is why I asked you how it is worded.
I would NOT be comfortable using a meter that can breakdown internally at half its rating if I were working in an arc flash environment.So thank joe for making this video and don't buy a Keysight.
Mismatches of inputs and ranges are examples of REASONABLY FORESEEABLE MISUSE, even if the documentation or markings prohibit such mismatch.
QuoteMismatches of inputs and ranges are examples of REASONABLY FORESEEABLE MISUSE, even if the documentation or markings prohibit such mismatch.
The attached image was taken shortly after design an construction of the transient generator (2016). Shown with 5kV peak, 100us FWHH, no load. This is the transient that damaged both Keysight meters.
Just out of curiosity, have you looked at the waveform of the grill starter output, across a nominal load of say 10MΩ, to simulate what it would look like to the front end of a typical handheld DMM?Well, I am not sure what "typical" would be but I don't think I have a meter that could be simulated with a simple 10M resistor. Case and point, I modified the UNI-T UT181A's layout to attempt to improve its ability to handle an ESD event. That PCB is part of the circuit and has inductance, capacitance.... That ESD pulse reaches its peak current in less than 1ns!
10MΩ should get you in the ball-park though? Maybe with some MOVs or GDTs in parallel... :-//
My understanding is these piezo ignitors don't pack much of a punch, energy wise, but can deliver maybe 10kV or so, happy to be corrected if wrong.
But now I think we get to the crooks of what you are driving at.
............ the crooks of what you are driving at. You suspect the grill start is putting out ...
:-DD :-DD :-DD
A megavolt? Not hardly. That would allow for a spark across a gap of a metre, never mind a meter!
You suspect the grill start is putting out 1MegaVolt which unfairly wipes out all of those UNI-T meters. :-DDI didn't expect you to read that as a literal statement but ok.
As I said, maybe 10kV.
If we use 1000V per mm, 10mm air gap for 10kV, I have no doubt that I have one grill starter that will exceed that.Maybe the post was too long for you.
What I was curious about is whether the the output of these things is too fast for the protection circuitry to react to, as it is obviously going to be way lower energy than the IEC standard tests for CAT ratings, and less than the 20J your transient generator puts out. My point therefore is, given these facts, how does it damage (for example Uni-T) meters? My only guess is it's too fast for the clamp(s).[/color][/size][/b]
I am not confused, I never mentioned ESD, that was Fungus and latterly yourself. I am asking a question. What does the transient generated by a grill starter look like across the inputs of a DMM?
You partially answered me by pointing out that piezo spark generators are very inconsistent in their output; fine, thank you for that information.
I then asked why the grill starter damages meters; is the transient too fast for the clamp, or is it something else? I mentioned CAT ratings and your transient generator merely to compare the energy levels involved.
I am asking for your considered opinion, or if you know the answer, that is all. I am not asking you to perform any additional tests.
What does the transient generated by a grill starter look like across the inputs of a DMM?, I assume you want to look at the voltage rather than the current. While I did show this from the UT61E's controller IC's perspective, it is not what you asked. Again, I would expect this to be different with each meter. I don't have a good way to look at it. It suspect it far exceeds any probe I have.
Life cycle testing has begun. How many cycles do you think the detent spring will last? Cast your vote...
It only has about 5000 cycles on it so far and lets just say things don'tOh, covers mouth with hand ! :scared:lookSound good.
I did write Dave about the U1282A that he swam with, drove over, tossed off the bridge, threw against the wall to see if he would be willing to part with the PCB to possibly salvage this meter. Maybe we will get lucky.
Sorry you Keysight fanboys. I am unable to continue the 50,000 cycle life test. I left a clue in the photo for you.But you are making a video about it...right? ;D
But you are making a video about it...right? ;DYes
BTW, I was wondering about the grill starter test.
In the video's it's not very visible, but I think you hold the end of the grill starter physically to the multimeter input terminal, right?
Does it make a difference when you don't do that and let it hoover slightly above that input terminal (say 1mm or so) and when you press the button, there is a spark over that airgap?Yes
Won't that ramp up the voltage considerably? (because of the extra resistance of the air gap)
Or is the total path of resistance then so high (airgap plus resistance in the meter itself) that no spark is even happening?
Dog4 has been with us almost 2 years now. She gets a lot of exorcise
Thanks for showing the stepper motor setup in detail.
Do you adjust the maximum motor torque for each test based on the force required to turn the dial?
Good job Keysight!!
Over spec the frequency input (Defpom claims they are changing the paper work to address this)
Data logging that glitches
Lettering that comes off easily
Poor input protection that not only will damage the meter at fairly low voltages, but does not protect the sensitive ICs that can not be replaced
A function switch that can't survive even a fifth of what the better class of meters can handle
I was wondering:
Have you ever cycle tested the rotary switch on one of the smaller Brymen meters? I couldn't find anything about that.
I believe you have the BM235 and BM319 that fall in that form factor?
I saw both the BM869S and BM839 cycle tested, and results were similar after 50k cycles, and I guess that makes sense as they're situated in virtually the same housing and the switch also looks virtually the same.
But the BM235 and BM319 have a smaller housing and maybe a differently sized switch? It would be interesting to see how those smaller meters performed in the switch cycle test.
I've posted a few clips of their setup. I think they actually had a similar meter on their jig in those clips.Ok, but having a meter on their jig is not the same as showing the result of the test of course. BTW if I look at those clips from Brymen, to me it looks like a BM869s and some current clamp is shown, but the clips are not very clear and maybe I'm looking at the wrong clips. (I look at the clips you show in your BM869s life cycle video; funny enough the rotary switch from what I believe is a BM869s in the Brymen video doesn't sound very healty to me (the clicking), but in your test the indent spring had no wear whatsoever; but of course we don't know what was in that Brymen meter in the video from Brymen, they just as well might have been experimenting with glass fibre reinforced plastics for indent springs ;D)
So my question is: what happened here? Is this the same meter that you used in the first test? And are Fluke 17B+ rotary switch contacts lubed or not?It seems perfectly logical to me. What happened? I would say "time" happened. From the first video dated Dec 2015, it was supplied with lubrication. In that same video the meter had been damaged and I talk about ordering parts to repair it. It doesn't appear I made a follow up video showing the repairs. There's no magic disappearing grease. I obviously cleaned the PCB when working on it.
I don't really understand what happened here, but it doesn't seem logical to me.
I searched in this thread but couldn't find a real explanation for this.
I think this could require big changes to a meter's front-end, but I'd love to see if the FLIR DM92/3 would "come-a-gutza" under your hands! At this level it competes with Fluke, so if we could get Flir to send you one, it would be nice to know if the switch can take a good beating too. I bet you'd knock it out with the grill starter and send them back to the drawing board :-DD
After this, voltage measurement is 'good' as before, but resistance measurement is affected by the added components. No surprise for me, when I short the leads I get ~2K reading.
After this, voltage measurement is 'good' as before, but resistance measurement is affected by the added components. No surprise for me, when I short the leads I get ~2K reading.
I am not quite sure, but my guess is you need to recalibrate and adjust your multimeter to compensate the additional resistance of the additional components.
I have a crappy Axiomet dmm with no input protection. I wanted to have some fun with it so I cut some traces and added in series with V/ohm input a 2W 1K resistor, a 1K PTC and a MOV back to COM input.
What happens when you apply five thousand volts across the range switch of a cheap ass multimeter? I'm glad you asked
zing. but seriously, real talk - im absolutely devastated by how far HP fell. gender equality for all - carly fiornia proved that women can be as savage as men in business. she managed to take a marvelous, competent company (from the health sciences to VMS/nonstop banking mainframes -- and everywhere in between) and fracture it off in search of short-term profiteering and performance bonuses. i digress.
It even says right on the box:
Retool Your Expectations
:-DD
hey joe, can you test the NGK low-emi plugs and see how meters respond to those HV EMPs? (i.e. the standard "meter resets", or what have you)
...
so i guess my question is, how can i tell if the particular sample i have has had some or all of the problems you observed corrected? since it came with v1.22 i don't have much hope though. and thanks for the videos even though about 75% of your tests i'll never have to worry about unless there's an electronics apocalypse in the future or i end up going to a ham radio field day! :)
/guy
I saw your comment on YT and decided to check in. Yes, I have dialed back my usage of this site as most of the posts now pertain to topics (religion, politics, race) that I have no interest in reading.
I saw your comment on YT and decided to check in. Yes, I have dialed back my usage of this site as most of the posts now pertain to topics (religion, politics, race) that I have no interest in reading.
Not true. But you do know there are Topic, Thread and even Board Ignore lists, right?
... where I came here for more technical discussions related to electronics.
Thinking of this thread and non related topics, I had a discussion a few days ago (pinned comment on attached video). The FAQ cut down on much of the questions and it's been a while since someone wanted to troll the channel. Normally, I wouldn't think anything of it but what's interesting is they post "... as a college instructor of electrical engineering, ...". The context is great. After a quick search, I believe this is true. :-DD
Did you attend any higher education? If so what were your teachers like? It appears here in the USA, the requirements for working in education change state by state.
https://youtu.be/zzQ57h2vGV0
am i missing something? ...
as to your question about higher education, were you addressing that to someone or seeking responses from anyone? if the latter, i'm glad to supply one, but it's staggeringly long (tl:dr territory!)Based on the OP's grammar and attempt to troll the channel, I wouldn't have guessed they were involved in education outside of maybe attending high school. A quick search seemed to show otherwise. This had me wondering what are the requirements for various states when we look beyond the high school level. A bit of an eye opener.
/guy
am i missing something? ...
:-DD Yes, but it's because the OP pulled their comment which deleted the entire chain. This isn't uncommon for trolls. I expect most of them are aware World Wide Web means just that and once you post something up on social media, it's there for good. See attached.as to your question about higher education, were you addressing that to someone or seeking responses from anyone? if the latter, i'm glad to supply one, but it's staggeringly long (tl:dr territory!)Based on the OP's grammar and attempt to troll the channel, I wouldn't have guessed they were involved in education outside of maybe attending high school. A quick search seemed to show otherwise. This had me wondering what are the requirements for various states when we look beyond the high school level. A bit of an eye opener.
/guy
My questions were directed towards anyone with a higher education. Military, university (all colleges call themselves that but you know what I mean), community college, anything goes. I bet there are some good stories out there.
Thinking back, I had some really good teachers. They were all very professional and many came from the industries they taught in. I had made an attempt to contact one of them several years later just to thank them but sadly they had passed away.
I saw your comment on YT and decided to check in. Yes, I have dialed back my usage of this site as most of the posts now pertain to topics (religion, politics, race) that I have no interest in reading.
Not true. But you do know there are Topic, Thread and even Board Ignore lists, right?
Sorry, not true? I assume you are referring to my comment of religion, politics... and not that I dialed back my use of the site or that I had seen the OPs comments. You may have taken that to mean these three specific topics which wasn't my intent. This is why I had closed with:Quote... where I came here for more technical discussions related to electronics.It's not what topics are being discussed, rather it's whats missing. Filters are not going to improve that. Anyway, hope this clears things up.
I saw your comment on YT and decided to check in. Yes, I have dialed back my usage of this site as most of the posts now pertain to topics (religion, politics, race) that I have no interest in reading.
Not true. But you do know there are Topic, Thread and even Board Ignore lists, right?
Sorry, not true? I assume you are referring to my comment of religion, politics... and not that I dialed back my use of the site or that I had seen the OPs comments. You may have taken that to mean these three specific topics which wasn't my intent. This is why I had closed with:Quote... where I came here for more technical discussions related to electronics.It's not what topics are being discussed, rather it's whats missing. Filters are not going to improve that. Anyway, hope this clears things up. [/b]
You are not correct that when you said "as most of the posts now pertain to topics (religion, politics, race)"
That's simply not true.
Here is a list of the most recent topics as I post this, zero of what you mention.
Yes there is odd topic here are there that might drift into that, but practically all of the forum is electronics related in some way.
If you don't think there are any good electronics topics that interest you, then ok, each to their own, but don't blame it on "religion, politics, race topics".
Start a thread on a technical topic that interests you and watch people join in.
Those free meters have gone through several hardware changes over the years to reduce cost. Even if we saw a difference between the two meters I show, I couldn't tell you if it had anything to do with the label or not.
Is 1100V the limit? Seems to me like a 2000 count meter should be able to display 2000V... :popcorn:
From their video it looked neat, then I looked at the specs. 0.3% 60000 count meter for $140. WTF
From their video it looked neat, then I looked at the specs. 0.3% 60000 count meter for $140. WTF
Well the ad does state "high precision" not great accuracy. Still, is 60000 counts really high precision. I think that Gossen I have is 300000 count and the Brymen BM869s supports 500000 counts in a few modes.
I wonder what that PCB is that they show. It looks like some sort of meter with the large shunt and HRC fuse. Maybe a development tool for firmware.
I wonder if that's not a dev board for the meter? Same number of input jacks populated, close on the buttons.The display has too few digits. The board must be for a different meter.
At this market, though, electrical and mechanical robustness are kings as well as track record, but for the latter there is nothing that can be done at this time.
Once again, single PTC with nothing else to limit the current. With what they are starting cost now, I'm surprised they aren't using proven designs. They look to be about the same package as the parts that came in the 61E+.
Once again, single PTC with nothing else to limit the current. With what they are starting cost now, I'm surprised they aren't using proven designs. They look to be about the same package as the parts that came in the 61E+.Well, in all fairness it seems they might be learning a thing or two from your previous failure analysis. If my eyes are not failing me, the HV path seems to have a pair of PTCs, two pairs of clamping transistors and a larger resistor R57 they think might hold back a serious surge.
Once again, single PTC with nothing else to limit the current. With what they are starting cost now, I'm surprised they aren't using proven designs. They look to be about the same package as the parts that came in the 61E+.Well, in all fairness it seems they might be learning a thing or two from your previous failure analysis. If my eyes are not failing me, the HV path seems to have a pair of PTCs, two pairs of clamping transistors and a larger resistor R57 they think might hold back a serious surge.
However, it is a hefty price for a somewhat basic Uni-T.
Once again, single PTC with nothing else to limit the current. With what they are starting cost now, I'm surprised they aren't using proven designs. They look to be about the same package as the parts that came in the 61E+.Well, in all fairness it seems they might be learning a thing or two from your previous failure analysis. If my eyes are not failing me, the HV path seems to have a pair of PTCs, two pairs of clamping transistors and a larger resistor R57 they think might hold back a serious surge.
However, it is a hefty price for a somewhat basic Uni-T.
Assume R67. I would need to trace it out. Normally you would basically have two MOVs in series (shared on the return leg). Ignore the second leg for now, you end up with one PTC in series with a MOV. Say the MOV is 1kV. If I apply 2kV, thats 1kV across the PTC. Maybe it can handle it. Those stupid piss ant 5mm parts they use in the cheap meters come apart and arc over. Then there is nothing to limit the current. In this case, let's say we have that SMT resistor in series with the clamp. The clamp is basically a 0V and the 1kV is now across that resistor. Maybe it survives. Does it at 6kV? :-DD I like the tried and proven methods some of these companies have adopted. Still, it doesn't mean they can't still screw it up. The 121GW for example has the basic parts but the simple grill starter damaged the production meter with ease, just like so many UNI-T products. Designers have to to their job.
So we're back to the big question: Does the meter have to survive the transient to get a safety certificate or does it only have to protect the user?
I'd say that a big bang in your hand isn't "protecting the user" - even if the blast is contained they might step back from fright, put their foot in a bucket and fall off the scaffolding.
I was hoping Joe, Dave, Kerry Wong, or another of my favorite YT'ers would look at this meter soon. I've been seeing it go for around $85 alone or $100 with the kit (clamp leads and magnetic hanger) for a 60K count meter and thought it looked like it had interesting features for the money. Sure, Dave's BM786 is a far better 60K count meter I'm sure (I do love mine), but the cost is twice as much. Not sure I've seen another 60K meter in this price range, at least from a brand you've actually heard of.
Note: I have an unashamed addiction to buying and collecting handheld multimeters of all stripes. I have some of everything, and multiples of several, including Fluke, Hioki, Brymen, Aneng/Zoyi/Zotec, Greenlee, Voltcraft, Craftsman, Uni-T, Owon, Hantek... you name it and I probably have at least one. I definitely don't need another meter. Just curious as to whether this one might scratch the itch to add to the collection, lol.
Take a look at the specs though. This meter is literally an order of magnitude less accurate than any other 60k count meters. What good does that extra digit do if it's not accurate??? To me, it's close enough in price to the BM786 or 789 that if I want a 60k meter I would still prefer one of them. If I wanted cheap I would get the 61E which has better accuracy than this meter.
I am VERY confused by that teardown pic and the specs. That looks like a HY3131 chip, which is definitely capable (with the correct other hardware of course) of much better accuracy than this meter.
I would say YOU are back to ... Don't wrap every one else into your safety chatter.
Take a look at the specs though. This meter is literally an order of magnitude less accurate than any other 60k count meters. What good does that extra digit do if it's not accurate??? To me, it's close enough in price to the BM786 or 789 that if I want a 60k meter I would still prefer one of them. If I wanted cheap I would get the 61E which has better accuracy than this meter.
I am VERY confused by that teardown pic and the specs. That looks like a HY3131 chip, which is definitely capable (with the correct other hardware of course) of much better accuracy than this meter.
Interesting. I didn't really look into the specs, I just saw a new 60K meter from Uni-T at an attractive price point. I just assumed it would be at least as accurate as a 61E+ (which I also happen to have). I don't understand why they wouldn't take a fairly proven (if not perfect) design like the 61E+ and add the precision to it for $25 more.
Interesting. I didn't really look into the specs, I just saw a new 60K meter from Uni-T at an attractive price point. I just assumed it would be at least as accurate as a 61E+ (which I also happen to have). I don't understand why they wouldn't take a fairly proven (if not perfect) design like the 61E+ and add the precision to it for $25 more.
It's got "electrician" features
Interesting. I didn't really look into the specs, I just saw a new 60K meter from Uni-T at an attractive price point. I just assumed it would be at least as accurate as a 61E+ (which I also happen to have). I don't understand why they wouldn't take a fairly proven (if not perfect) design like the 61E+ and add the precision to it for $25 more.
Their web page claims "high precision", not high accuracy.
https://meters.uni-trend.com/product/ut117c/
EDIT: Actually the 61E+ is now selling for $82 on AliExpress, virtually same as this meter. I was thinking the 61E+ was quite a bit cheaper. So I guess the upshot between these meters is you can have precision or accuracy for the same price, just not both.
Like, I don't care about safety an my testing has nothing to do with it. I've made that statement many times over the years. Never sinks in with certain people.I would say YOU are back to ... Don't wrap every one else into your safety chatter.
Huh? Somebody else mentioned "61010" a couple of posts up.
I believe you have access to a copy so maybe you could make a definitive statement on the matter. End speculation.
I don't understand why they wouldn't take a fairly proven (if not perfect) design like the 61E+ and add the precision to it for $25 more.Your idea of a proven and perfect design certainly differs from my own. I like that 200MHz frequency counter function it has.
Huh? Somebody else mentioned "61010" a couple of posts up.Like, I don't care about safety an my testing has nothing to do with it. I've made that statement many times over the years. Never sinks in with certain people.
I believe you have access to a copy so maybe you could make a definitive statement on the matter. End speculation.
EDIT: Actually the 61E+ is now selling for $82 on AliExpress, virtually same as this meter. I was thinking the 61E+ was quite a bit cheaper. So I guess the upshot between these meters is you can have precision or accuracy for the same price, just not both.
My question is why would you ever buy a Uni-T? You can get the 61E's accuracy in a Zoyi for much less money (the ZT-219/Aneng 870) and you can get a genuine CAT III meter from Brymen with input jack alert, etc., for the price of this meter.
The only interesting thing I see in the Uni-T lineup is a data logging meter for about $80 (the 61E). I don't think any other brand can match that.
(nb. Zoyi have some Bluetooth meters but I don't know if the protocol is known/hacked)
I know the UT61E has an army of fans though so that's just me.
I don't understand why they wouldn't take a fairly proven (if not perfect) design like the 61E+ and add the precision to it for $25 more.Your idea of a proven and perfect design certainly differs from my own. I like that 200MHz frequency counter function it has.
Huh? Somebody else mentioned "61010" a couple of posts up.Like, I don't care about safety an my testing has nothing to do with it. I've made that statement many times over the years. Never sinks in with certain people.
I believe you have access to a copy so maybe you could make a definitive statement on the matter. End speculation.
I never said you did.
The standard is written around "safety" so that's the word I'm forced to use. Please stop trying to be obtuse.
And by "fairly proven" I refer simply to it's aforementioned popularity among hobbyists -- it has definitely proven itself a popular and capable meter for it's price point with that demographic.
And by "fairly proven" I refer simply to it's aforementioned popularity among hobbyists -- it has definitely proven itself a popular and capable meter for it's price point with that demographic.
Right, like the free Harbor Freight meters. May be the most popular meter out there and tough to beat that price point.
He also did this video:
https://www.youtube.com/watch?v=z4KClzousA8 (https://www.youtube.com/watch?v=z4KClzousA8)
comparing the AN870 and the 61E+, and it was really no comparison.
He concluded with "Personally, I'd pay the premium for the more expensive Uni-T UT61E+ if I had to choose one or the other."
BTW I also have an AN870, which is certainly a decent meter for the money, but as soon as you handle it you recognize it's very cheaply made.
BTW I also have an AN870, which is certainly a decent meter for the money, but as soon as you handle it you recognize it's very cheaply made.
I'm more of a fan of the AN860B+.
As I have stated many times, that standard has nothing to do with my testing
Talking about safety from the context of this thread shows a lack of understanding.
FWIW I asked the AI and got this answer:
I had momentary access to a few versions of the 61010 and it is quite ambiguous - I recall Joe had the same impression. I had commented before in this thread that IME such standards are subject to pressure from various players in the industry and such specific point might have well been kept somewhat ambiguous on purpose, clearing out the market for varying degrees of performance under transients.Talking about safety from the context of this thread shows a lack of understanding.
The question isn't about safety. The question is whether or not the meter is supposed to survive it's rated transient without damage.
My belief is that the standard is ambiguous on this point but I don't have a copy the standard because it's expensive and not much use to me.
It seems logical to ask somebody who does have access to the standard if they could clarify things (or simply confirm that yes, it's ambiguous). :-//
One of the reasons that IMO is a strong indicator of the 61010 ambiguity is the line of Hypertough meters sold at the large Walmart stores in the US. Their M830B clone (manufactured by All-Sun) is way better than the average crap meters but I don't think it would qualify.
it withstood 280VAC applied to all its ranges - except battery tester, hfe and A/mA.
As usual, I did a review (https://youtu.be/SskaKJfSyXM) for my channel. My feelings are mixed - despite it is of a lesser quality than the A/B brand meters, it is built to a much higher quality than the M830B clones, which a great deal of people that can understand Portuguese uses them in extremely dangerous scenarios. Disclaimers galore but I would be happy if people used this particular one instead of the über crap stuff you find in Brasil.
I had momentary access to a few versions of the 61010 and it is quite ambiguous - I recall Joe had the same impression. I had commented before in this thread that IME such standards are subject to pressure from various players in the industry and such specific point might have well been kept somewhat ambiguous on purpose, clearing out the market for varying degrees of performance under transients.Talking about safety from the context of this thread shows a lack of understanding.
The question isn't about safety. The question is whether or not the meter is supposed to survive it's rated transient without damage.
My belief is that the standard is ambiguous on this point but I don't have a copy the standard because it's expensive and not much use to me.
It seems logical to ask somebody who does have access to the standard if they could clarify things (or simply confirm that yes, it's ambiguous). :-//
One of the reasons that IMO is a strong indicator of the 61010 ambiguity is the line of Hypertough meters sold at the large Walmart stores in the US. Their M830B clone (manufactured by All-Sun) is way better than the average crap meters but I don't think it would qualify. However, Intertek mark is stamped left and right across its packaging and enclosure - no way Walmart would open themselves to a class action suit in case people started being electrocuted by one of their products.
I wasn't sure what you meant by this meter but I found your other thread.One of the reasons that IMO is a strong indicator of the 61010 ambiguity is the line of Hypertough meters sold at the large Walmart stores in the US. Their M830B clone (manufactured by All-Sun) is way better than the average crap meters but I don't think it would qualify.
:) That meter reminds me of my "Big Clive" meter, which I enjoy using - it's simple, it takes up almost no space, and it stays on all day long without complaint.
The case is really boring though. You'd think they'd make it stand out from the crappy DT830a so you can easily tell them apart. eg. The Big Clive has a Fluke-like rubber boot.
My measurement was quite close to the meter's maximum claim of 300V, but I should pull my HiPot tester and see if I can get it to display more (up to 2kV?).it withstood 280VAC applied to all its ranges - except battery tester, hfe and A/mA.
The Big Clive claims 500V on most ranges in the manual but I haven't tested it.
(I don't see hFE on yours in your video...)
Well... Brasil is a country full of suicide showers. People have a higher immunity to electricity there. :)Our ability to withstand 220V across our body is legendary. :-DD
I've mentioned before that I think Intertek has become a bloated, ineffective monopoly. Worse, it seems much of the cert is now rubber stamping for a price. I think it's more about trying to control trade than safety. My thoughts on that have not changed and this extends far beyond handheld multimeters.If you think Intertek is like that, there is a chance UL follows suit. I worked with them and, despite they were very professional and completed the work to its extent, there was a perceptible "checkbox-like" attitude.
:) That meter reminds me of my "Big Clive" meter, which I enjoy using - it's simple, it takes up almost no space, and it stays on all day long without complaint.I wasn't sure what you meant by this meter but I found your other thread.
The case is really boring though. You'd think they'd make it stand out from the crappy DT830a so you can easily tell them apart. eg. The Big Clive has a Fluke-like rubber boot.
https://www.eevblog.com/forum/testgear/trashy-meters-redux/ (https://www.eevblog.com/forum/testgear/trashy-meters-redux/)
Quite interesting indeed
:) That meter reminds me of my "Big Clive" meter, which I enjoy using - it's simple, it takes up almost no space, and it stays on all day long without complaint.I wasn't sure what you meant by this meter but I found your other thread.
The case is really boring though. You'd think they'd make it stand out from the crappy DT830a so you can easily tell them apart. eg. The Big Clive has a Fluke-like rubber boot.
https://www.eevblog.com/forum/testgear/trashy-meters-redux/ (https://www.eevblog.com/forum/testgear/trashy-meters-redux/)
Quite interesting indeed
https://www.newark.com/pt-BR/duratool/d03047/digital-multimeter-manual-2mohm/dp/78AH1731 (https://www.newark.com/pt-BR/duratool/d03047/digital-multimeter-manual-2mohm/dp/78AH1731)
Ref:
https://www.youtube.com/watch?v=-QDW0LRQVrY (https://www.youtube.com/watch?v=-QDW0LRQVrY)
Damn you, Fungus. Now I'm in for three of Clive's meters (need to feed this meter monkey on my back).
I like having "disposable" meters located in convenient places and I think I'm down to my last HF freebie. Plus this one is built way better, so may not be as disposable. Can't beat 7 bucks a pop, especially with the HF's going for $6 now. Like you I decided to get three to have spares and make better use of the flat shipping rate.
EDIT: Ha, also just noted these are from the same "batch" 2106 as your meters. Fake batch numbers anyone? Really big batches? Really slow sales?
If you have a meter you would like to see tested, feel free to post the brand, model, supplier.
Klein Tools
If there is something at this price point in the US.
I'd like to see one of those big chunky Aneng/Zotech meters, the ones that supposedly have a 61010 certificate.
eg. This one: https://zotektools.com/products/zoyiztm1/ (https://zotektools.com/products/zoyiztm1/)
The certificate is in the "Product certification" tab.
The Aneng versions are these:
https://www.aliexpress.com/item/33005381639.html (https://www.aliexpress.com/item/33005381639.html)
https://www.aliexpress.com/item/33009371206.html (https://www.aliexpress.com/item/33009371206.html)
I'd like to see one of those big chunky Aneng/Zotech meters, the ones that supposedly have a 61010 certificate.Read the selection criteria and pick a meter with autorange. These manual range meters suck up too much time.
Room for a few more.
Room for a few more.
This one: https://www.aliexpress.com/item/33008555587.html (https://www.aliexpress.com/item/33008555587.html)
:)
This one: https://www.aliexpress.com/item/33008555587.html (https://www.aliexpress.com/item/33008555587.html)
:)
Joe, I think one that has been making the rounds is the Kaiweets HT118A (https://www.amazon.com/KAIWEETS-Multimeter-Resistance-Capacitance-Temperature/dp/B07SHLS639/) and also sold cheaper as AstroAI M6KOR (https://www.amazon.com/AstroAI-Multimeter-Auto-Ranging-Capacitance-Temperature/dp/B08FDVQDM5/) - mind you, these are better built than the absolute bottom of the barrel I mentioned in the other thread.
Joe, I think one that has been making the rounds is the Kaiweets HT118A (https://www.amazon.com/KAIWEETS-Multimeter-Resistance-Capacitance-Temperature/dp/B07SHLS639/) and also sold cheaper as AstroAI M6KOR (https://www.amazon.com/AstroAI-Multimeter-Auto-Ranging-Capacitance-Temperature/dp/B08FDVQDM5/) - mind you, these are better built than the absolute bottom of the barrel I mentioned in the other thread.
The Kaiweets HT118E is the upgraded version. 20K counts vs 6K. These are actually pretty good meters for the money with rave reviews all over (don't know about protection though)
These are the Aneng M118A I referenced in my post above. They should provide a nice pyro show. ;DThis one: https://www.aliexpress.com/item/33008555587.html (https://www.aliexpress.com/item/33008555587.html)
:)
I couldn't find it on Amazon or eBay. If it is sold under a different brand/model, let me know.
It's made by Zotech and has lots of brands. The S3 or S4 are the ones to get.
On ebay:
https://www.ebay.com/itm/385405636448 (https://www.ebay.com/itm/385405636448)
https://www.ebay.com/itm/353583550051 (https://www.ebay.com/itm/353583550051)
https://www.ebay.com/itm/384324938870 (https://www.ebay.com/itm/384324938870)
Amazon is the worlds worst place to buy multimeters
I want products that hold up. Others want sexy colors...
It has anti high voltage :palm:
Klein Tools
If there is something at this price point in the US.
The Klein MM400 is under $60. From teardown videos it appears to have a single-PTC MOV-less design and a CAT III/600V rating, which seems suspect. However, it also appears to have a more limited function set, so perhaps they are able to pull off a "withstand without clamping HV" design. It does have a pretty decent looking set of input resistors, but not the single large ~1k surge resistor.
So, to mix things up a bit, I bought what I consider should make a decent meter for electronics work. Will it replace my Brymen BM869s.... Stay tuned.
... I really don't care about that. ...
Others do.
Others do.
Yes I understand. But in the light of the robustness testing that you do, do you expect any surprises of the ~sub$50 kaiweets/zotek/aneng multimeters that flood the market and sponsored youtube channels in that regard?
That one of them stands out and has a robustly designed front end that will perform well in your test?
Obviously the only real way to find out is to test them, but my expectations are pretty low regarding that aspect.
The functional tests that you do with odd voltages (like detecting ac waveforms with a dc bias etc) might be the most interesting part for those cheap meters.
Some time ago I suggested the amazon commercial 90DM610 (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg3130620/?topicseen#msg3130620) which was a rebranded Cem DT-9562 that at that time retailed at $49 on amazon that looks like it may have a pretty decent robust front end inside, but afaik that meter is not available anymore (certainly not at that price at least)
A few viewers will complain how the tests are unrealistic. How it says right on the meter 600V max. How we can't draw any conclusions from a sample size of one. How dare I take a perfectly good meter and damage it. How I am biased. How they had this meter for 20 years and it has never had any problems.There is another category: "I used this meter in my three phase distribution panel and not only it read 380V but I am still alive to tell the story".
There is another category: "I used this meter in my three phase distribution panel and not only it read 380V but I am still alive to tell the story".
Nice video. That was indeed an unexpected outcome, since EN61326 wasn't mentioned in the manual.
Let's hope all future Uni-T's meters handle the grill starter with no problems.
And it shows that a reasonable robust meter doesn't have to be expensive, although this is of course a pretty simple and limited multimeter.
Keep in mind when I first started to look at how robust these meters are, the meter that was the runner up survived 5kV. It could also be repaired. I tested it a second time on the new transient generator and it once again survived 5kV. That meter was also under $50 and had a lot more features.
The Y1 transistors they selected are a bit more stout than what I normally see for a clamp and they took some abuse.Thanks for sharing the link and P/N. I have some meters here that need their clamps changed and I keep forgetting to look at your older videos to get the P/N.
(...)
https://www.aliexpress.com/i/3256803936810470.html?gatewayAdapt=4itemAdapt (https://www.aliexpress.com/i/3256803936810470.html?gatewayAdapt=4itemAdapt)
Transient Testing the KAIWEETS KM401 4000 count DMM
Transient Testing the KAIWEETS KM401 4000 count DMM
(my wife would say "hoard")
.... wasn't that meter actually fairly inaccurate during some of your basic checks?
And what is with the TRMS not reading your half-wave source?