Handheld meter robustness testing

[Fungus]

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.

[Meter Junkie]

Harbor Feight DMM at 6kV blowing the input fuse.  Slo-mo

https://youtu.be/EeOvQ7VUYt8

Harbor Freight DMM with fuse shorted, blowing the traces. Slo-mo

https://youtu.be/BOsekwQO68Y

Uni-T 201 clamp getting chip blown off board at 6kV. Slo-mo

https://youtu.be/mdLRPyt0ND4

[Meter Junkie]

Interesting that the UT90A only failed on the diode test. I figured that it would have fried the resistance measurenment as well.

But, should ANY meter even be subjected to a 4kV surge on the diode test, resistance, or continuity?

The way I read 61010, surge testing like this should only be done on the MAINS measurement terminal. These tests are to simulate a lightning strike while measuring MAINS, or an inductive kick on the mains if power is broken from the serving transformer when that measurement is being taken. When would anyone ever see a 4kV, or greater, spike when doing a diode test or continuity.

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.

[Lightages]

As far as I understand the standards, every function is to be tested with every terminal.

[Meter Junkie]

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.

If the meter measures to 600V, then the standards require that the meter does not become a Hazard when 600V is applied to ANY terminal, and set on any dial position. So, I agree with your statement that Voltage should be applied to diode test, or the current jacks, etc.  This falls into the "reasonable misuse" of the meter category, where a user could have the meter on the wrong dial position, or plugged in the wrong jacks, and you go to measure a Voltage.

But, not the surge pulses.  The standard does not require you to handle 4, or 6, or 8kV when you are measuring a diode. This would never happen as a "misuse" of the meter, and you would never get a 8kV spike when measuring a diode.

[ivan747]

Have you tested the Fluke 101 yet?

[IanB]

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.)

[Lightages]

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.

[Meter Junkie]

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.

Attached is the section of 61010-2-033 that talks about testing for mismatch inputs. It only mentions applying voltage, not surges.

[Muxr]

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.)

If you're dealing with inductive loads you may also encounter spikes. Even a little DC relay can generate 300v spikes.

[Meter Junkie]

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.

Attached here is the section of 61010-2-033 that discusses the surge testing. This only discusses the function of the meter that tests MAINS, and only "IF" transient protection is used (because it is optional).  IF it is used, it can't fail, but it does not have to be used.

[joeqsmith]

Consider that one of the principal partners of IEC is the WTO.   Are the standards more about trade restrictions and bureaucracy than safety?

"... shall operate as intended ..."  As a designer, we know MOVs have a limited life like all parts.  They can fail in a not so nice way.  I would say this is intended operation.     

Maybe ask your TUV safety inspector their take on it.  See if you can nail them down....  Use the word "safe" a lot too!   

Again, my goal is not to debate a spec that is filled with holes.   

As for how products are used,  I would never underestimate man's ability to do stupid things, myself included!     

If you're dealing with inductive loads you may also encounter spikes. Even a little DC relay can generate 300v spikes.

I agree that while I am using the IEC standards as a guideline for my waveforms, there is nothing in those standards about the countless transients you can see when working even on low voltage.   If you ever used the old door bell as a transient generator, you know where I am coming from.     Testing the meters this way does not mean that they would withstand all of the conditions you can come up with.  It may however indicate what companies have considered protecting their designs for such events.     Would I buy or recommend a meter than lives or one that fails?   If it were to a novice, I would suggest the most bullet proof meter I could find.    If they wanted more features and a less robust meter down the road, so be it.     

One thing this testing has shown me is that as a novice, you could buy a very robust meter for under $50!   

The meters I have are all being tested the same.   Not having it automated, and every meter being different, there are a few things that change and this is why I left the entire tests in the video.  It's not there because it is so exciting to watch, it there if someone were to question what had been done.   So not a lot of drama or fluff but at least it may provide people with some sort of real world testing to help them make a decision when it comes time for them to purchase a meter.   

 

Time to start thinking about what to do with so many non-functional meters.......

Buy/Sell/Wanted.   DMMs like new little used. 

Are you making an offer??!!         

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.

This has always been the plan.   Don't underestimate my ability to break things!      Yea, I can ramp it up alright!     The key has been to make small changes.  Otherwise, they may have all failed at once and we would not really learn anything from the experiment.

So stay tuned!

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 the current testing is concerned, I would expect the next meter I purchase to handle at least a 4KV spike in diode test.  I am way beyond that now and a few meters are still fine...   

I can believe that manufactures would make arguments like this to side step the fact that their products are not as robust as a competitors.   This makes no difference to me.  The testing continues.....

Have you tested the Fluke 101 yet?

Both Danaher meters are in good hands....     


Sorry for the long post.    The moment you have all been waiting for... The SEMI FINALS!!!!

[Lightages]

Great! One question. What happened to the UT139C. Your last video ended before the end of the testing. Did I miss something?

[joeqsmith]

There's only room for one meter at the top!   I have continued to modify the home made generator throughout this testing and it is on the brink of failure as it is now being pushed to 6KV in an attempt to take down one last meter!   More capacitors means less room and more Teflon has had to be added to prevent internal arcs.   I never expected any of these meters to survive the conditions I have put them through.   I think the ones that have really deserve my business.   No matter of my personally feelings about Fluke after buying my first one in the early 80's,  they have come a long long way to improve their designs if they can make a $50 meter survive the tests so far.   

I wish the Fluke's continuity function worked better and it had back light for the LCD.   

The same for it's brother, the AMPROBE.  Dang, it's one tough meter!  It has more features than the Fluke, like AC/DC current and NCV.   Not to mention that the continuity feature is fast and it has an LCD back light.   

One last test to run, one last video to make.   

Great! One question. What happened to the UT139C. Your last video ended before the end of the testing. Did I miss something?

So many videos, so much data, so little time.  I watched and no, you did not miss anything.  I must have edited it out or something.       That was the best part of the whole video too!!!   So I won't spoil it for you.   Let me make a single video just for the 139C.   It will be worth it!

[Lightages]

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.

[joeqsmith]

It's not so much that it died, it is how it died.  The video will be well worth watching.   I'll get it up there in the next day.   

I was joking with a friend of mine about this experiment and I made the comment that every one of the meters I had bought for it was better than any hand held I had ever owned in my entire life.   I think when it comes to making a recommendation the best you can do is help educate people so they can make better choices. 

[Fungus]

It's not so much that it died, it is how it died.  The video will be well worth watching.

Shrapnel?

[joeqsmith]

It's not so much that it died, it is how it died.  The video will be well worth watching.

Shrapnel?

I'm sure if I ran the real test with the mains, we would have had some real drama.   

Video is processing now...

[joeqsmith]

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.

Here is the UNI-T UT-139C taking the hit.   Enjoy.
https://www.youtube.com/watch?v=2GjB3eUpDFY&feature=youtu.be

[Muxr]

Fluke meters at the low end are very spartan, they don't skimp on protection but the features take a back seat. But sounds like that Amprobe is a real winner though. I mean in that price range it's got a decent set of features and it can take the abuse.

Although Fluke 101 has its compact size going for it for a sort of a pocket meter.

[Vgkid]

I was amazed that you killed the Klein, I liked its small size/lack of features.

[ivan747]

As far as I understand the standards, every function is to be tested with every terminal.

But the meter is not required to survive.

I can see some companies will want the meter to survive on AC volts range, for example, but on diode test they would just let the thing break inside safely as per the standards.

[Fungus]

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.

[Lightages]

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.

[Muxr]

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.

Amazon lists AM-510 at $37.88. Pretty impressive.