Poll

Are you interested in seeing more handheld meters tested?

This testing is pointless! Please STOP damaging these meters!
3 (6.4%)
 Yes, I would like to more meters tested.
44 (93.6%)

Total Members Voted: 47

Author Topic: Handheld meter robustness testing  (Read 649626 times)

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Online Wytnucls

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http://www.westwayelectricsupply.com/dm-860a-dmm-500k-counts-dm-860a.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
 :box:
1. No stock? $325.00 is a good price, if available.
2. Very low stock $313.00
3. Unknown stock $366.00 ($40 less than the Fluke)

Big price differences between US retailers ($417.00~$313.00). Doesn't make much sense to me.
« Last Edit: October 11, 2015, 08:26:52 pm by Wytnucls »
 

Online Wytnucls

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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. :-//
Lifetime warranty, whatever that means at Greenlee.
 

Offline Lightages

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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. :-//

 :-DD Multimeters as fashion accessories....
 

Offline 5ky

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Oh, it's come down in price. I remember the 87V being a lot more when I bought mine.  Good to see it drop in price.  Half the price would be more accurate then.

However, if we're talking people in EU or AU getting getting an 87V versus the brymen, I'd say that's probably every bit of 1/3 the price for the brymen.

EDIT: I lied, just found my invoice.  Paid $314.  I bought it with Fluke's leather bag / probe set which was what jacked the entire order's price up.
« Last Edit: October 11, 2015, 06:37:40 pm by 5ky »
 

Offline joeqsmith

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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....
« Last Edit: June 26, 2017, 02:21:26 am by joeqsmith »
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline 5ky

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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

 

Offline PedroDaGr8

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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.
« Last Edit: October 13, 2015, 02:20:09 am by PedroDaGr8 »
The very existence of flamethrowers proves that some time, somewhere, someone said to themselves, "You know, I want to set those people over there on fire, but I'm just not close enough to get the job done." -George Carlin
 

Offline joeqsmith

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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.

 :-+ Looking forward to 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

Yea, I think you know first hand that 15 meters is a pretty big project to take on.    :-DD  PM'ed you about the meters.
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline joeqsmith

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THE FINALS!!!!    With the RadioShack, Brymen BM869s and Fluke 107 taking on the 13KV generator.    Again, big thanks to 5ky for making this happen!!   

https://www.youtube.com/watch?v=Dchy-0u-W7A&feature=youtu.be
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline tautech

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Hats off to you Joe.  :-+
What a great series.  :clap:

Your drop test.  :o 
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Offline 5ky

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Awesome!  I loved the supercut of the discharges at the end.

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?
 

Online Wytnucls

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You seem full of praise for the Brymen and scorn for the Fluke 87V.
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?
 

Offline poida_pie

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Joe,
Thanks for doing all this work, showing how to safely test these meters.
After all this, I am now interested in how the Flukes were designed so that they survive the 12kV pulse.
Time to search for teardown photos of the input protection and maybe also schematics...
This is the result of your work: it's made me start thinking and looking for myself about how and why.

Brillant effort
 

Online Fungus

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Thanks for doing this. It's been a long slog but a lot of good data was produced.

I might have to get me a Fluke 107...

 

Online Fungus

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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...?
 

Offline Lightages

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You seem full of praise for the Brymen and scorn for the Fluke 87V.
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?
Yes, I was wondering too.
 

Offline poida_pie

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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...?
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.
It's time for me to learn about MOVs and the other protection device's real properties.
 

Offline joeqsmith

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Thanks for the kind comments.   

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...

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.   

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...?
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.
It's time for me to learn about MOVs and the other protection device's real properties.


Take it for what its worth, I have now put 23 meters to the recycle bins.  It's not a lot of data but worth a high level rundown of the types of failures I have seen from running these tests.   


I would say the highest failures that cause the meters to be non-repairable, the control IC is damaged.  This happens a lot.  To be clear, I am not at all suggesting that the IC is the problem with the designs where they fail. 

Transistors/diodes.    This is been a very common theme.  In these cases, most appear to be setup as a clamp.  In many cases, these parts will blow apart and become an open.  Then the transient will continue to the next part.  Normally the control IC.   In most cases where the IC was damaged, a clamp was damaged too.   Most, but not all.   In some rare cases I suspect the IC was damaged with no other damaged parts. 

PTCs have taken their fair amount of damage.  I most cases, they still work even though they arc over.  The arc will often damage the outside coating assuming it has one.  Parts that do not have this layer just arc around the outside.  Of course, this nice low impedance arc will go to the next thing down the chain, normally the clamp.    In some rare cases the PTCs were damaged beyond the point where they would function.

MOVs  Well, my own experience with MOVs is they degrade and short.  Their cases will catch fire and crack.   For the meter's I have damaged, I have never seen an MOV fail.    This does not surprise me at all nor should it surprise anyone here.   The MOVs used are normally behind a PTC and are going to handle a fair amount of energy.   Again, the amount of energy I am using to test these meters is VERY small.   Enough hits' I would expect to see them degrade.     This again is why I get confused when people talk about correlating these tests with meter safety.  That's just stupid.  There just is not enough stored energy to do anything like explode a meter.   And again, that was never a goal of mine....   Sorry for beating the dead horse, yet again....

Resistors  I was going to post HV resistors but that may confuse a few people.  In several cases, I have seen the front end built with 1206s and other small packages.   Some meters will use little MF 1/4 axial parts.   This is not always a problem but there was a meter in this last set of tests that used 1 pc of a 1/4 MF resistor in series with a PTC then to a MOV.    :palm:    Worse, I think that meter had footprints for some HV parts!!   Again, everyone wanting to make their profits.   Like the Brymen, this particular meter had two different circuits, each with their own single 1/4 MF resistor, going to the Vin jack.   Both of those resistors opened up. 

Circuit boards   There are two things I see happen.  Traces will not handle the surge and become damaged.   In some cases, this has caused even more damage to other circuits once they open up.    The other problem has been lack of creepage distance. 

Other  Let's stop using lead in solder again  :palm:   Here's an idea, make reliable products that don't end up in land fills!   I have seen more than one solder joint fracture.   Some are just poor hand soldering.    Normally, problems like this I just fix and move on with the testing.   That said, most of these are now lead free and look good.   Time will tell how this plays out.

So I stated in the video that I thought it would not take a whole lot to get the Brymen to pass that last test.  While the Brymen BM869s was damaged, the two transistors still sort of worked.  In most cases, when the diodes or transistors like this have failed, there was enough going through them to make the damage very visible.  :-DD   Take that Danaher 87V for example.  Three diodes damaged and the transient cracked every case.    As you saw from my video, that Brymen can read in the pf.   So shoving a MOV across the input with 2000pf may not be such a smart idea but in some cases this may not be critical.    I don't think you will find a single one size fits all fix.

If we wanted to talk about safety, I think you need to consider that in some cases what I wrote about the failures may have been by design to prevent a hazard.   Take for example the meter that I mentioned from 5ky that had the two 1/4W MF parts.   Sure I bitched about the pads allowing for a larger package.  However, that fact that they opened my have been by design to prevent a hazard.     :-//   I don't know, nor do I care as I have no interest in using a meter like this in a high voltage high energy applications.    I am interested in a meter that is robust as well as feature rich.   The Brymen BM869s is the best I have seen for my use.   

Sorry for the long post.  Hope it helps tie things together.   


You seem full of praise for the Brymen and scorn for the Fluke 87V.
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?
Yes, I was wondering too.

Fluke, what can I say that has not already been written in the history of Fluke and Danaher. 

"At Danaher, our vision is that associates and customers will demonstrate extraordinary loyalty; that we will be respected and admired by all who come into contact with us;...."

I admire the way the $400+ 87V is tested in your labs but blew the backs off of three diodes during a test that your $50 meter withstood!  A $50 meter that you do not even mention on your US website nor offer in the US.    Good Job Danaher, you have my respect!!    And really, isn't the fact that I have taken the opportunity to post videos about my very first digital meter that I have kept over three decades, demonstrate my extraordinary loyalty to the brand?     You have placed yourself on a pedestal for all to admire.   

Brymen, what can I say.  I am impressed with your website!   :palm:   I know you wrote that the BM869s would not survive my 6KV hit by design,  but you were willing to back me up and push ahead.   When the BM869s was damaged, did you back out knowing very well I had just hit the meter with far more than it was ever designed to handle?   No, you held up your end.   And when I offered to have a look at the meter to see what had happened, did you say that would void the deal.  No, you hung right in there.    That is trust!  You are an engineering company for engineers not some princess on a pedestal!  I have no doubt reading the history of your company where you are heading.   

If I wanted to buy a Danaher/Tektronix scope to put on a pedestal I would but I am surrounded by old LeCroy scopes for a reason!
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline tautech

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Hard to argue with that Joe.

Companies that will stand behind the user are few these days.  |O
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Online Fungus

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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
« Last Edit: October 15, 2015, 12:13:27 pm by Fungus »
 

Online Wytnucls

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Seems to me you resent having been snubbed by Fluke for not paying any attention to your multimeter 'killing fields'.
I admire the way the $400+ 87V is tested in your labs but blew the backs off of three diodes during a test that your $50 meter withstood!
That 'test' is of your own invention. It is not required by IEC regulations, who should know a thing or two about multimeter safety. The Fluke and the Brymen only require a set of crowbar transistors to protect that range up to 1000V, not 13kV.
A $50 meter that you do not even mention on your US website nor offer in the US.
A very basic cheap CAT III 600V averaging meter for the Asian market. Surely Fluke has the right to release some meters in specific markets, as they see fit.
Brymen is a smaller company trying to make it big in foreign markets. It is understandable that they would be more receptive to unusual requests coming out of the US.

For the record, I got stellar service from Fluke in China, being invited and escorted to their main office in Shanghai. I was allowed to try out several replacement sets of TL910 electronic test probes, until I was satisfied with their quality.
When I bought a Fluke 101 in Malaysia, I was given a good quality Fluke polo shirt, which was probably worth more than the meter!
« Last Edit: October 15, 2015, 01:19:44 pm by Wytnucls »
 

Offline Lightages

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So Fluke is a big company and Joe didn't get attention for something he thought was important. The tests are well thought out and actually very informative to us and, more importantly, to Joe. It is his criteria for what makes a good company and/or good multimeter. This is what Joe relates and states emphatically.

The Brymen BM869S failed in a similar way to the Fluke 87V. So is it equal to Fluke? It doesn't mean that necessarily. It means that with Joe's tests, and in this case it failed in a similar way. Joe had more help and response from Brymen. It is reasonable to feel that a company is more interested in the customer when they respond and support the customer. This is not just Joe's experience, but also that of Wytnucls with Fluke in China. Does this make the experiences equal? No. Does this make them both invalid? No. They are data points to be considered.

Joe prefers the BM869S over the Fluke 87V for his reasons and from his experiences. He has stated his reasons clearly and without obfuscation. Some people will prefer Fluke over anything else based solely on their history and reputation. No problem with that.

Should you select a multimeter based solely on the tests of Joe and nothing else? That is up to you but Joe has his criteria and you might have your's that are in conflict. That is what choice is about. It is ironic that one of the cheapest meters from the models available from one of the most respected brands in the world bested the highest regarded model in these tests.


Many thanks Joe and 5KY for your contribution to our knowledge.

 

Online Wytnucls

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I wouldn't dream of using my Fluke 101 on anything above CAT III 600V as per its highest rating, confirmed by a CSA safety listing.
I would have no qualms using a Fluke 87 V in a CAT III 1000V environment.
Nothing I have seen in these high voltage tests is going to change that position.
 

Offline Lightages

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So would you use a CATIV/1000V rated meter, tested and confirmed by UL, over a CATIII/1000V meter, confirmed again, in a high energy situation?  :box:
 

Online Wytnucls

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Not particularly. In a CAT III situation, any properly rated meter for that environment would be fine. The Fluke 101 too, if not more than 600V.
If I need autohold, the Fluke 87 or the Gossen 26S, if in a cramped space, the 101.
When did you last work in a CAT IV 1000V environment?
« Last Edit: October 16, 2015, 05:34:36 pm by Wytnucls »
 


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