Handheld meter robustness testing

[joeqsmith]

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,
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               (Fluke 28-11 owners will love that s***)   

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. 


Well, it's been another VERY long day of meter testing.  Let me just say from my perspective of running these test, it's one thing to buy a meter that is in production that anyone can buy and then run these potentially destructive tests on it.  Running a meter that you know there are only a very limited number made is a whole different story. If it were my design, I would be all for running it to failure.  I've been in that position many times.   

The video is currently rendering.  Because of the meter not being released yet, my plan is to allow Dave to review it first and make sure there is nothing proprietary being shown.   I've kept things pretty basic and not expecting there to be problems.   So stay tuned, it shouldn't be much longer.   

[joeqsmith]

The video is in Dave's hands now. 

The house was pretty warm today and that LeCroy DSO makes for a small space heater.  I decided to put one of the battery powered Flukes to work.  As beat up as these were, so far they seem to be working fine.  This one needs a new EL after seeing how bright the other one was after replacing it. 

[joeqsmith]

Dave reviewed the video and has approved it to be released.  I will allow Dave to comment on the findings.   

[EEVblog]

Dave reviewed the video and has approved it to be released.  I will allow Dave to comment on the findings.   

Thanks Joe, I commented on the Youtube video but will repeat that here:

SPOILER ALERT:
Thanks for the testing Joe. We think we may have uncovered a potential cause of failing at the 2kV impulse and will be looking into that. It was most likely the 2kV impulse on the ohms range that caused the failure at that point, as there is no mechanism whereby the Volts range could potentially fail at that voltage.
The meter is still under development as you mention, so changes are still on-going.
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).
It is also being ETL certified to ensure full safety compliance of course.?

[imidis]

Thanks Dave and Joe

[kcbrown]

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!!!

Surely it'll pass the kite string test...






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[EEVblog]

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!!!

I'll pay that!

[jordanp123]

Looks like I'll be acquiring one, once they are released.

[Fungus]

Will David L. Jones be the next John Fluke? 

I think purple would be a better color.

[floobydust]

Troubleshooting 61010 impulse testing fails... don't impulse test because it's destructive and good luck finding out where the breakdown occurred.

My method is to use a HV power supply made of a car ignition coil and PWM circuit to generate mild HV. Or a high-pot tester.

Apply this to the circuit and you can hear/see the corona or make an arc. If the breakdown location is really elusive, do it in the dark but keep your nose away 
If you keep the HV applied for a long time (many seconds), ozone buildup occurs and the air breaks down at a lower level which can be misleading.
You can also place Kapton tape in the areas you guess the breakdown is occurring and look for results.

[Fungus]

Of course it's fast, it uses a flux capacitor!

(just don't go over 88Hz)

[EEVblog]

Troubleshooting 61010 impulse testing fails... don't impulse test because it's destructive and good luck finding out where the breakdown occurred.

Yes, tracking down the exact mechanism of the failure like this takes a huge amount of time, effort, and busted meters.

[Fungus]

The snowball test is a new one. 

https://www.youtube.com/watch?v=wkrbohiuUwU&feature=youtu.be&t=32m10s

[Fungus]

Of course it's fast, it uses a flux capacitor!

(just don't go over 88Hz)

The CEM meters I have are really bad.  So is the TPI. 

Whoosh?

[Crumble]

[...]
You saw a meter change 30X after being dropped?

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... 

[joeqsmith]

[...]
You saw a meter change 30X after being dropped?

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... 

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.   

[Crumble]

No problem, sorry for that. 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. 

[joeqsmith]

No problem, sorry for that. 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. 

Yes, that is correct.   I have not heard anymore from them but sure would like to see that risk assessment. 

[joeqsmith]

Has anyone done any tests on the fuse kits Dave is offering?  I am interested in comparing data.   

[joeqsmith]

Video showing the 400mA ASTM fuse.

[Muttley Snickers]

I probably would have done it in the same manner anyway but for a minute there you had me worried using the Dremel free hand in that way, I haven't tried it with those ceramic fuses yet but with most of the other glass fuses you can just heat up the metallic tips with a lighter so as to melt the glue for removal of the ends, I have had to do this out in the field on the odd occasion but don't tell anybody.   

Also, and I know you have mentioned it in the past but those scratches on the Uni-T meter are just horrendous and not getting any better with time, I hope they are taking notice of your videos and how badly these screens are holding up, additionally it looks like somebody could do with a hair cut.   

[oh2hyt]

How close power measurement matches if you change 181A measure voltage between fuse input and amps jack of 121GW?

Also interested if 121GW does voltage measurement for power calculaltion referenced to amps jack or common jack (and estimates full burden voltage for calculation, or does it measure also full burden voltage)?

[joeqsmith]

Anyone else watch bigclive's last video and think it was going to be the end of that CEM meter?

[bitseeker]

Yeah, I jumped almost as high as his cats, despite knowing what was coming.

[MacMeter]

Once I heard "made for bad boys and girls", half way through video, I immediately began to wonder if JQS is coming up with some new MM testing protocols? If so, DYNAMITE!!!