Handheld meter robustness testing

[joeqsmith]

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.

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?

I have stated this a few times as well about the standards should be available for free if the concern is really with the public.   If you want a copy, they are available for purchase.   

The requirements are not clear in many areas. 

REASONABLY FORESEEABLE MISUSE

  These 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:
.....

Note 4.4.2.101 does not talk about surge.   For that, refer to 14.101. 

14.101 Circuits or components used as TRANSIENT OVERVOLTAGE limiting devices in
measuring circuits used to measure MAINS

This is the section I read aloud in the one video.     

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.

Hopefully that answers your question

I wonder how that is actually tested without putting a person in harm's way?

[Fungus]

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.

If your tests could make it fail much below its rating then you'd probably be getting a call from Fluke to investigate.

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).

[joeqsmith]

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.   

[joeqsmith]

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.

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.     

[joeqsmith]

And a last minute entry arrives all the way from China. 

[Lightages]

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!

[joeqsmith]

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!

I have started testing again.  I see no point in setting up to run the lower energy transients to see where UT139C fails by comparison.   Rather I have meters that will pass my current levels so I plan to just test this one with them.   If it lives, it will stay with the meters that pass.  If it dies, we just know it was not a contender for the top $50 meter bracket.   

While the IEC  standard calls for a 1.2us rise/50us decay with an open and a 2 ohm source at 4KV, I again caution everyone that even though I am now testing at slightly over 3.7KV with a 50us decay into an open and with a 2 ohm source, there is no AC involved.   Do not consider these tests as any more than they are, pure entertainment and maybe some bragging rights. 

Another meter just failed...   RIP my friend.     

[Vgkid]

You killed the Klein.

[Meter Junkie]

    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.

The generator that I use is for telecom.  This is not the one I use, but is in my lab. This generator pictured is "supposed" to be for IEC 61010 testing only.

There are 2 output jacks. You plug into the ones on the right for 12 ohm, and on the left for the 2 ohm output. There are two plugs for each output to allow two wires to handle the current, but keep the wire gauge down so they are flexible.  This machine does not allow AC into it, and is just the pulse. When they want to use AC with it, they put an inductor in the circuit between the AC and the pulse. But there is no syncing the pulse with the peak of the AC.  Since the spec say the maximum AC that the pulse can be riding on is 400V, I guess you could get the equivelant by just adding an additional 400V to the pulse and setting it for 4,400 or 6,400, or 8,400.

[joeqsmith]

You killed the Klein.

 

Klein has that "Tougher Than" project.   Someone needs to link these videos for them and show them that there are a few people who actually are putting their product through an electrical test rather than having a chicken peck at it or an RC car drag it. 


Klein, tougher than Cen-Tech
Klein, tougher than Mastech
Klein, tougher than Gardner Bender
Klein, tougher than BK Precision
Klein, tougher than EXTECH

and the list grows.....

Just finished testing.  Included the new 139C in the mix.   3 of the 5 meters survived and you know the Klein Tools MM500 is right there on top.  Lot's of sparks and some nice part fragments to show for the last several hours.

And you people that think a meter is hard to design to handle this sort of punishment, well, there appears to be a few companies that can get the job done! 

I am afraid this is the end of the road for the toy generator.  The remaining three meters have taken everything I could throw at them.   It will take me some time to build something larger.   In the mean time, enjoy the videos.  I'll put the new ones up in a day or so.

[Fungus]

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.

[joeqsmith]

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.

Many cheap ones may not but we are looking at some high quality, low cost meters 

Top set is for the AMPROBE AM-510, center is from the Klein Tools MM500, lower is from the UNI-T UT-90A.   Personally, for what I would use a hand held meter for, these are all fine.  If I had to pick, it would be the BK probes.  Guessing they are made by the same company as the MASTECH but with the threaded end, I have some other tips that will work with them.

I like some of the Fluke probes and own one of their sets.   Second picture shows the probes I purchased for the attenuator versus my Fluke probes.   These work very well for probing fine pitch and other small parts.   They are CAT III 3A rated. 

Hope this helps.

[Meter Junkie]

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?

[joeqsmith]

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?

Not really.   I would like the test the high dollar meter against the surviving $50 meter on a real setup.   

Videos are done processing.  Should be able to post them tonight.   

[Mark]

Look what arrived today!  An 8kV surge generator. 

I thought I had some cheap-assed multimeters for sacrifice, but I now remember throwing them out... so the cheapest I have is a Maplin N72CG...  it is looking nervous. 

[joeqsmith]

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.   

[Meter Junkie]

Well,

I hit a $5 Harbor Freight DMM with 12kV through 2 ohms today.  I was less than impressed by the failure.  Just a flash, with no flying components.

[Mark]

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.   

30 sec for 8kV and 15 sec for 4kV, haven't had time to do much more than that with it!

[joeqsmith]

Good deal.  Starting to not feel so alone.   Let's see some video from these real generators doing the deed! 

Running the surviving four meters at 3.2KV.   WARNING!!!!  THIS IS A VERY NON EVENTFUL VIDEO!!!!  It's just there so you know I ran the test.

[joeqsmith]

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!

And here you go.   The brand new UNI-T UT-139C is tested against the four remaining meters.  It had never been subjected to any transients compared with the others that have been through a small war.  It had the advantage.   

Three meters remain in full functional condition after this....

[Vgkid]

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

[joeqsmith]

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

Don't worry, I took care of it in the next round!!   

Testing continues tonight at 5KV 2ohm 40uS (open).  Still 1KV off their rated, no AC and 10uS short.     

 One more meter was lost so far besides finishing off the UNI-T UT90A.   One has passed and the last one is being tested now.   We may have our winner tonight!!   



After hitting it a second time, I took this meter apart.  Next to the PTC, there is R46.  There is a VERY thin trace that routes from R46 to the switch.  Then from that same section of the switch to a via to a much wider trace.  The two sections of thin trace were vaporized. 


As it turned out, there were three very small traces that were vaporized.  I spent some time repairing them and tried the meter out.  Close but after looking further there is a part that appears to be shorted as well.   

[joeqsmith]

I am sorry to say that I have been unable to declare a winner.  The two remaining meters must actually handle the 61010 standard and stay functional.   

Klein Tools, tougher than UNI-T

[Muxr]

baby Fluke still alive?

[tautech]

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

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