Poll

How many cycles will the KeySight U1281A's detent spring last?

0-2000
7 (17.9%)
2k-4k
5 (12.8%)
4k-8k
14 (35.9%)
8k-16k
7 (17.9%)
>16k (most rubust meter ever made)
6 (15.4%)

Total Members Voted: 36

Author Topic: Handheld meter robustness testing  (Read 1150069 times)

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Offline Lightages

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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.
 

Offline joeqsmithTopic starter

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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 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. 

Offline Meter Junkie

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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??
 

Offline Lightages

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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?

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
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

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.

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.

All a insulation breakdown tester will show is when arc over will occur, but no necessarily damage the item under test.
« Last Edit: July 05, 2015, 05:29:02 pm by Lightages »
 

Offline Lightages

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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??

Oh for probably something like 10 seconds. I have a bank of 8x 250Ah AGM batteries wired in 4 serial by 2 parallel. They have a new internal resistance of around 4 milliohm. So actually I would only get around 5000A. I forgot that I had to remove a third string when two batteries went bad.

I do have access to 3 banks of 4x4 of the same batteries, so yes I could easily get 10000A for 10 seconds at least.

They are for solar power storage.
 

Offline joeqsmithTopic starter

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Video showing the last couple of days including today running the 101 with that 13KV 100us FWHH 2 ohm setup, 3 hits both +/-.     

https://www.youtube.com/watch?v=DBBdhyzGk00&feature=youtu.be


Quote
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.

This should be a walk in the park for you then.    I look forward to seeing your setup.

Quote
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
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

I checked the links.  It's a bit too high priced for me just to run it against the Fluke 101.   

Offline Lightages

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Quote
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.

This should be a walk in the park for you then.    I look forward to seeing your setup.

I really want to build something with some bite to it, the problem is getting the parts in Chile like I said. I will try, but I have so many other things to do.

Quote
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
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

I checked the links.  It's a bit too high priced for me just to run it against the Fluke 101.

Yes I understand not wanting to throw money every which direction.
« Last Edit: July 04, 2015, 04:39:52 am by Lightages »
 

Offline Meter Junkie

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Happy 4th of July!!!!!

It seems like a good day to blow stuff up with a homemade surge generator....
 

Offline Meter Junkie

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So, now that this testing is complete, what's next?

As discussed earlier in this thread, the possibility of most meters ever seeing a surge like this is very slim. It was very fun to see how the meters performed, even though they will seldom have to.

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?

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?
 

Offline joeqsmithTopic starter

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Happy 4th of July!!!!!

It seems like a good day to blow stuff up with a homemade surge generator....

 :-+   Happy Independence Day!    As they were importing tea from China, now we import the Fluke 101 from China.  Although I saw a video where someone took it apart and they suspect that at least the board was made in India,  where the tea also came from.   Maybe I'll throw the thing into the harbor and see if that damages it!   :-DD


Offline Lightages

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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?

The best I can do right now is high current or high voltage. I can't do both. I do have a big variac and some transformers I can play with along with a neon tranformer. I will see what I can do after I get caught up on some other things. If you don't hear from me again, I probably touched the wrong part of the circuit whilst experimenting. :scared: (don't worry, it won't happen)
 

Offline joeqsmithTopic starter

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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?

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


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.   

« Last Edit: July 04, 2015, 06:34:17 pm by joeqsmith »
 

Offline Lightages

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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.
 

Offline joeqsmithTopic starter

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But is a 1000 or 5000 at several amps very likely?   I can't answer that. 

I took a 1000uF, charged it to 440V, using a large solenoid and some 16AWG test leads I made for this test, spanked the 101 with it while in resistance, diode and continuity.    There are two time constants.  It decays rather rapidly to 240 volts, then just hangs out around there until I cut the power.   

This seems to have no affect on the 101, but I assumed from the 61010 standard, it wouldn't.   Here is a short video recorded at normal speed which provides some idea of the time constant.   


Offline Lightages

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But is a 1000 or 5000 at several amps very likely?   I can't answer that. 

No, not very likely, but possible in some power supplies that I have worked on in the past, at least 1000V at 1A and higher. If  meter is rate at CATIII/1000V, then it better handle more than a couple of milliamps at 1000V on all functions and all input jacks. I still do not have the full IEC specifications for the tests, but the parts I do have do not indicate the current availability for this kind of test, at least I am not sure. I have one clause that states:

Quote
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.

So based on this, I guess, that a meter rated at 1000V maximum input must be able to not cause harm with a source of 3.6A if CATI or CATII, and 30A if CATIII or CATIV. So an insulation tester capable of a few milliamps will not give you any real indication of the ability of the meter to pass this part of the test. If it fails at a few milliamps, that just mean it failed to operate after. It is very hard to cause harm to the user with a few milliamps contained in the meter housing.

I have another clause from somewhere that states:

Quote
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 do not know what the voltage required in 4.4.2.101 is, so I am shooting in the dark. Like I said before, it is ridiculous that a safety standard for the public, made by public funds, is hidden for payment.

Edit:

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.
« Last Edit: July 04, 2015, 11:06:02 pm by Lightages »
 

Offline Meter Junkie

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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


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.   

4.4.2.101 covers just the mains terminal, and it states that the MAINS must handle 1.9 times the rated voltage for the unit up to 900 and something for a 600 V meter, and up to 1100 V for a 1000V rated meter. Then, 101 covers handling the voltage on other inputs that are not expecting that voltage.  But, like I said, this is for 3rd Edition, and companies don't need to be supplying these until 2018.  The majority of the meters out there today are to 2nd Edition, and handling the full voltage is not required.

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.  Look at the specifications for some of those cheap meters that were out early in your testing (I'm sure you still have the manuals laying around).. I would bet that if you look at the overload protection on some of those functions they are around 250V.  So, these could probably (if they really meet that spec) pass 250V, but could turn to a fire bomb at 480V, or the 600V the meter is rated for.

Now, would I use a $50 Mastech meter when measuring 480 or 600??  Heck NO!!   But, there are users that would, and they may not be safe if they had the meter set wrong.

As for the currents that could be available real world, you know that any AC line you are on could deliver greater than 30 Amps if presented by a dead short in the meter, after something fails due to the over voltage. Finding a DC system with that current behind it would be much harder, and would be something like a third rail on a train.  I wasn't saying that finding a DC high voltage application with current behind it would be common. I was saying it would be easier to have a DC test jig.

For us to get access to 600V with 30A of current behind it would be unlikely (and extremely dangerous). Even if we had a 240 to 600 step up transformer, you would need 80 Amps on the primary to get that current for testing.  With DC for testing, we could use batteries, or charge big enough caps to keep that power sustained for a while. For small caps they would create more of a "surge" that the front end could handle for a few milliseconds.  But, would they blow with more power behind it for a while??

I'm assuming they would, but I don't have access to AC with that power.  I've looked a caps to charge, but a 1300V 480uF cap runs around $200 (with my quick search), and you would need a lot of those to sustain this for a while. 

This seems harder to test, but a more likely failure that can happen.
« Last Edit: July 05, 2015, 12:53:45 am by Meter Junkie »
 

Offline Meter Junkie

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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.

Yeah, milliamps (like your Megger) won't show how bad a meter would be damaged.  I can get to 3000V with 500mA behind it, but I'm not sure even that would give enough power to wipe out meters like Fluke does to the Harbor Freight meters in all their videos.  Maybe I should just pick another one up to see. The last 2 I bought had the voltage jack fused, so maybe they changed the design.
« Last Edit: July 05, 2015, 12:57:55 am by Meter Junkie »
 

Offline joeqsmithTopic starter

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Quote
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.
:-+

Quote
4.4.2.101 covers just the mains terminal
101 refers to 4.4.2.101.   Mismatch of leads is covered in 101.3. 

Quote
16.2 Multifunction meters and similar equipment
I would think this would be the limit of 4.4.2.101 as well but I am not sure. 

Again, I can see how come I get different answers from the companies who make the meters.  Someone at TUV needs to write the the IEC61010 guide for dummies!    I would buy it!  But I bet all we would see inside is how it is up to the companies themselves to determine the risks.

Quote
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.

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.     

You like using that four letter word "safe" but if the goal is to determine something about safety, I can't help.   That's best to leave with the TUVs, CASs and ULs of the world! 

Quote
I can get to 3000V with 500mA behind it,

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.   

My first Fluke died twice.  Once from me measuring a HV supply that was near what the meter was rated for and I assumed it could handle it.   That was the first $70.    Later the meter was hit with a little back EMF and again died.   The HPs I now have have never failed.   I bought them both new.  The oldest must be more than 20 years old now.      The last two handhelds you saw.  The LCD was cracked after I dropped the one.  The other HF one had a mechanical failure with the LCD.   Then there's the BK that I think the switch just wore out on.   I really have not seen a lot of failures during my life.   I did see a guy hook a thermocouple input to the AC mains once that damaged a meter but even that is the only thing that comes to mind.   

I can see things like someone wanting to check their car ignition system and hooking it to the output of one of the coils.  For that matter, even on the primary side.    Or hooking it across something like a large starter solenoid or a fuel shut off valve with no flyback protection.     As mentioned earlier, many transients don't come from the line.   

Offline Meter Junkie

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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. 

My point was that it would be pretty easy to protect the resistance input from 50V, or 220V, but not so easy to protect it from 1000V.  Just like it may be easy to protect the meters you tested from 2000V through 50 ohms, but not so easy from 13kV through 2 ohms. You wanted to see how much abuse they could take from surges, and I'm wondering how well they would hold up from a mis-match.

 
Quote
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.
 

I wasn't saying a meter commonly sees 3000V at 500mA. I'm not just trying to damage meters. I could come up with many ways to damage meters is that is what I was looking for.  I was saying that is all I have to work with, and that won't let me test these the way I would like.  I would like to see how they can handle 480V, 600V, or 1000V, on any input.  With that supply I was mentioning, I could give them the voltage, but the limited current would not simulate what would really happen if someone put a meter across 480V that had the potential to supply 30 Amps.  I've seen a dozen low end ($5 Harbor Freight) meters blown up on videos with that fault. I'm curious how $50 or $100 meters would do. I also know spikes can come from many sources other than a lightning strike. But, I'm also pretty sure there are a lot more meters plugged into high voltage on continuity or Amps, than seeing spikes.

Again, I'm not saying that you were testing these meters to meet IEC for spikes, and I want to test them to meet IEC for voltage on a jack that shouldn't be there.  I'm just curious what meters could handle that, and which couldn't. But, I don't have a way to test it, and I was hoping others did.  If not, and I want to see it, I'll have to look at building it myself (when I have the time, money, and enough desire).
« Last Edit: July 05, 2015, 03:51:13 am by Meter Junkie »
 

Offline Meter Junkie

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Quote
4.4.2.101 covers just the mains terminal
101 refers to 4.4.2.101.   Mismatch of leads is covered in 101.3. 

Attached is 4.4.2.101 which covers the Voltage levels to the MAINS.  Yes, I know mismatch was specific to 101.3.  I was just saying that was in section 101, and not saying the specific section.
« Last Edit: July 05, 2015, 04:06:10 am by Meter Junkie »
 

Offline joeqsmithTopic starter

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To be clear then,  you would like to test them to the 4.4.2.101?   

If you just want to see how the meters hold up electrically,  you may not need the full 30A.   I have an 600Vish 350W supply sitting here from an old radio.   I could see someone who is attempting to work on old systems like this, hooking their meter to it.   It has not been turned on in many years.  Let me blow the dust off and see how the 101 likes it. 

Almost forgot, that will be 60Hz AC average voltage.   

« Last Edit: July 05, 2015, 07:27:55 pm by joeqsmith »
 

Offline Meter Junkie

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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.

When you started this whole thread, you wanted to determine how "robust" under $50 meters were.  To determine this you decided to see how well they could handle high voltage surges.  You referenced the surges required to meet CAT ratings, and built a generator loosely based off this standard.  You were not testing that they met the IEC standards, or trying to prove if any did not meet standards, you just wanted to see which meters held up to these surges the best, and that would determine which was more robust.

I also would like to see how robust meters are, but with another type of test.  Instead of how robust they are in surges, I would like to see how robust they are in handling a voltage on a position that is not expecting a voltage (like resistance, or capacitance).  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.  So, for a robustness test, it would be interesting to see which meters can survive the highest voltages on these various switch positions. None of the meters should go much beyond the voltage they measure to.  I would expect that the PTC's and MOV's are set to clamp just above that level.  Once you get above that, it is just a matter of how long before those protection devices can't handle that voltage. I'm not trying to prove if any meter meet the attached standard, I'm just curious which ones could survive the longest.  I'm also not interested in testing this for the current jacks, just the functions that would work off the same jack as the voltage, but in the wrong switch position.

What voltage would meters see on these positions, and what is reasonable??  I don't know, and I don't care.  It's not about how high of a voltage is reasonable on that jack, just how you kept taking the surge as high as you could, until you could get a failure.  But, I do know a lot of inexperienced people put meters on high voltages without knowing it.  I had a friend that damaged a cheap meter because he tried to measure the voltage coming out of a dog shock collar, and that was on the voltage position. 

I would expect a unit like the Fluke 101 to be able to take the full 600V on all levels.  I don't know how far beyond 600V it would go, but I'll bet it would go farther than any of the units you tested for the surge.  I would bet the Mastech unit would fail not too far past 300V.  Look at the link for the spec sheet of the Mastech 8261 you tested.  It lists the maximum voltage on the mV position as 250V, and protection on other positions like resistance as 380V.  This would not be a "more robust" meter.

http://www.p-mastech.com/images/Manual/ms8261%20english%20manual.pdf


I'm also not asking YOU to test this.  I was saying this wold be something I would like to see.  If nobody else does testing like this, I just may have to do it myself.  I'm sure that I can get enough power out of my transformer to damage the meter, and determine how robust it is for handling the voltage.  What I may not be able to determine id "how bad" the damage "could have" been.  Once a meter fails due to high voltage on the wrong input, it could become shorted inside, draw lot of current, and fail violently.  My transformer would not be able to show that.
« Last Edit: July 05, 2015, 10:10:52 pm by Meter Junkie »
 

Offline joeqsmithTopic starter

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Quote
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

Quote
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.

 :-+

Quote
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.

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...

Quote
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.

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....

Quote
https://www.youtube.com/watch?v=QEMCrGchLxs&feature=youtu.be

Offline Lightages

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So the way I read the specs that I have seen, in the end:

1. All terminals must withstand the rated voltage of the highest voltage stated on the meter, in every position of the function switches.

2. If there are any current limiting devices, they must function without any outward sign of them function or failing in any way, and must not be damaged or incur damage to the meter.

3. After the tests have been run, surge and cross function testing, the specs imply but do not state explicitly, that the meter should function well enough to show the highest rated voltage on the voltage function.

4. The specs do not imply that the meter must function properly on all functions after the test, just that it must show a proper voltage reading on the voltage functions after being subjected to the tests.

5. The tests should be done with the included test leads as they are part of the impedance path.

6. In all cases, the user must not be exposed to any harm as result of the test voltages and currents being applied.
 

Offline joeqsmithTopic starter

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Well, the specs say what they say.   I guess you could interpret them this way.   I would say for the part we are now looking at,  101.3.4 comes into play:

101.3.4 Test leads for the tests of 101.3.2 and 101.3.3

Sure you state that
Quote
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.   


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