Handheld meter robustness testing

[joeqsmith]

Anyone notice a new Brymen clamp meter, the BM037 that Dave apparently will market ?

We think you should put it through its paces Joe. 

We?  You and Dave? 

Searching you will find it mentioned in 2020 so it's not a new product:
https://www.eevblog.com/forum/testgear/clamp-meter-safe-reliable-and-under-$200/
More info is here:
https://brymen.eu/shop/bm037/
https://brymen.eu/wp-content/uploads/biall/102194/102194.INSTRUKCJA_EN..2019-02-26.1.pdf

I have never transient tested a clamp meter.  Not being an electrician, it's not something I would have much use for.   I suspect the lack of interest suggests other hobbyist also have little interest in them.  For automotive, I normally need something much more sensitive to detect high leakage currents.  On the bench, I would typically want something with much higher BW.  I like that old 1960's Tektronix P6042.  I was able to improve the UT210E's bandwidth by designing a new front end for it.  Sadly the typical UNI-T quality insures a short life as I have seen several of these now where the switches have failed after a few years. 

Guessing if Dave plans to sell it, he will make a review.  You may want to suggest tests for him to run. 

[tautech]

Anyone notice a new Brymen clamp meter, the BM037 that Dave apparently will market ?

We think you should put it through its paces Joe. 

We?  You and Dave? 

With the fun you had with 121 I'd have thought you'd be 1st in the cue to check it out. 

Searching you will find it mentioned in 2020 so it's not a new product:
https://www.eevblog.com/forum/testgear/clamp-meter-safe-reliable-and-under-$200/
More info is here:
https://brymen.eu/shop/bm037/
https://brymen.eu/wp-content/uploads/biall/102194/102194.INSTRUKCJA_EN..2019-02-26.1.pdf

I have never transient tested a clamp meter.  Not being an electrician, it's not something I would have much use for.   I suspect the lack of interest suggests other hobbyist also have little interest in them.  For automotive, I normally need something much more sensitive to detect high leakage currents.  On the bench, I would typically want something with much higher BW.  I like that old 1960's Tektronix P6042. 

Yes, wonderful bits of kit these old current probes and have had a P6021 for some years and added the 120MHz P6022 to my kit a year or 2 back.

Guessing if Dave plans to sell it, he will make a review.  You may want to suggest tests for him to run.

And put the fox in charge of the hen house, not bloody likely !


Anyways, just stumbled on it yesterday on YT:

[joeqsmith]

I liked that 121GW because there was a lot of hype about Dave's involvement and it being a custom meter from the ground up.  Having features we don't typically see in a handheld meter.   You may have noticed a shift towards meters I 1) feel have a chance of actually doing well against my tests  2)  something that the hobbyist would want

I did go back and look at that little pocket Brymen I had left outside and beat the crap out of.  Mine over ranges at 600V.   I've had that cheap UNI-T UT90A up that high.  After damaging it so many time, it seems to breakdown around 1.5k now (see attached).  This meter has such poor creepage, the PCB acts as a spark gap right across the main feed, saving the meter.   It's one of the few UNI-T products I have looked at that can survive the grill starter because of this built-in spark gap.   Of course, that's all fine at the low energy I would normally experiment at but I show the problem when you have something like this happen with a little higher energy.   

https://youtu.be/aRuI_q_K5RY?t=410


My P6042 was a trash pick in VERY poor condition.  It took a few weeks to repair it.  Sorting bags of transistors looking for matched sets.   I was able to get the bandwidth up to about 100MHz with it.  Impressive for the age of the thing.   It belongs in a museum like much of my equipment.   One day I will open up my home lab to the public and charge admission.   

And put the fox in charge of the hen house, not bloody likely !

The Brymen products I have looked at appear very robust when compared with other brands.   We will see how this second Keysight performs but based on the first, I don't have a lot of confidence.   

[joeqsmith]

I think I once caught one of Dave's live streams maybe for the 121.  I never see any notices about them.     I'm skipping around it now.  Is there something specific you would like me to watch or just in general?   

[tautech]

I did go back and look at that little pocket Brymen I had left outside and beat the crap out of.  Mine over ranges at 600V.

Hmmm, is it a different model to that bd139 has ?
He said his started crackling at 2kV but that was with a low energy CRO EHT supply.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4367380/#msg4367380

My P6042 was a trash pick in VERY poor condition.  It took a few weeks to repair it.  Sorting bags of transistors looking for matched sets.   I was able to get the bandwidth up to about 100MHz with it.  Impressive for the age of the thing.

They certainly are however I only have the 60 & 120 MHz passive AC current probes with their BNC terminations and also picked up a Type 134 amplifier for them....just to have really as the passive terminations are far more convenient.

I think I once caught one of Dave's live streams maybe for the 121.  I never see any notices about them.     I'm skipping around it now.  Is there something specific you would like me to watch or just in general?   

[joeqsmith]

Thanks for the link.  Didn't realize that was recent.  They could try placing it across a MOT if they wanted to see if the meter would do more than crackle.        

I have the BM27. 

I really don't have any high voltage supplies that put out any kind of current.  Nothing close to what PhotonicInductions channel shows.   My transient generators have a lot of safety features designed into them now and are relatively low risk to use.   The half cycle generator will not run without the small high voltage generator.  I short the high voltage outputs with a chicken stick before handling anything and wear hand condoms if I am doing anything too risky.   

[joeqsmith]

Watching Dave's live feed.  Starts out talking about the video feed setup.  I didn't see anything of interest during this.   You may want to skip ahead. 

About 17 minutes in.  He's talking about UNI-T and margins.   That mA res is hard to beat for automotive and I don't really need absolute accuracy.  Plus they give it away.  I would pay them double for a higher quality version of it.    22:47, UNI-T mentioned again..  Surprised no one is jumping in.     25:30 in, looking it up.   Dang, $70 now.  I thought  we were getting these for $30.

Interesting comment about the UNI-Ts display being sideways.  I like it that way.   The are talking about leakage now and accuracy.  IMO, I don't normally need it. 

29:00 talking about UNI-T 61 now.   Of course we have the Fluke 87.

30:00 discovers UT210B.  Talks about wanting lower current version for electronics.  Straw pole, pretty much everyone wants the lower current range.

35: starting to ask about using a standard DMM with shunt.   

Wanky low...    P6042 lowest range is 1mA.   Looks like there's one on eBay for $600 yankee dollars.  Maybe someone will want it.   

https://www.ebay.com/itm/325309029169?epid=1400242944&hash=item4bbdeddb31:g:qjAAAOSw-GNi~did&amdata=enc%3AAQAHAAAAoDongduZ9OKRFo20SQM3ytETKrD8C%2F%2By7T3I3ORHH4jd9vtjWk7TNPYq%2BZ4yj7BubEglOpFhqXCcYRd8dy%2FKy301iOxBnj4duOA%2B4T5NkLsyPypXadQrDvXxBP%2B2%2F%2F7DvmGn9UtsU9M%2BUd2AirSnK32Do6wWwEQmU3HBAuAbzqSynAnp5fRmmzF3TWZYyN%2BdEXM%2B2v1%2FlYS7gfcjpZ46OSo%3D%7Ctkp%3ABk9SR4SM_YzXYA

41:00  Taking it apart.    Hummm.  Small diameter PTCs.   Thicker than what I have seen on the really cheap meters.   May hold up. 

43:35 Brymen vs Fluke, input protection, who's the leader???

50: pulls the main PCB out. 

51: under NDA. 

53: trace wiggles and poor layout

55:19 I missed something.  He reads a comment that is shown in the chat about the meter not being good enough for Dave's branding.   
I thought that about the 121GW. 

Ok, that's the end.   I gave the video a thumbs up.  Meter seems alright but isn't something I would have a use for.   

[TCbystander]

While I think some of his testing being is not always directly useful, except for entertrainment, one thing I do value him for is irreverence and following facts where they take him. And he honestly documents data as it is, good and bad...

-40 degrees, 50K rotations, 100ft dropping, 14K transients, etc...  seems like an ElectroBoom review, just for fun. Almost zero probability of this use. (I won't ever use it above 1000V (or even 400V), and if this happens will be 15K, 30K, or 100K? doesn't matter, this is Very Far from the Max Specs).

It is not merely a matter of the rated voltage 1kV you use and test your meter. If a meter is claimed to be rated to CAT IV 1kV meeting the IEC 61010 series in its user's manual, for example, it has to survive the IEC transient test requirement of 12kV from a hybrid impulse generator with a source impedance of 2 Ohms. It is a 1.2/50uS OCV + 8/20uS SCC combo waveform capable of delivering 6000A peak currents. It resembles the magnitude of transients at the source of the building's MAINS. If the meter failed the test, it failed the manual specs it claimed IMHO. 

[joeqsmith]

It is not merely a matter of the rated voltage 1kV you use and test your meter. If a meter is claimed to be rated to CAT IV 1kV meeting the IEC 61010 series in its user's manual, for example, it has to survive the IEC transient test requirement of 12kV from a hybrid impulse generator with a source impedance of 2 Ohms. It is a 1.2/50uS OCV + 8/20uS SCC combo waveform capable of delivering 6000A peak currents. It resembles the magnitude of transients at the source of the building's MAINS. If the meter failed the test, it failed the manual specs it claimed IMHO. 

Possibly true depending how you interpret the standards.   We've had a several discussions about this and I spoke with two of the large manufactures about it early on.  There seems to be no consensus.  If you have any data (you work in this area), we would like to hear your take on it. 

I also want to again be very clear that the tests I perform have little to do with the safety standards.   Outside of basing my open circuit voltage waveforms on the standards (and still with a twist),  they really share no common ground.   This is covered in the FAQ.   

[rsjsouza]

(...)
Ok, that's the end.   I gave the video a thumbs up.  Meter seems alright but isn't something I would have a use for.   

I think the meter might be alright as well with protection well above your average chinese product, but the fact the rotary switch is in the center and not on the side is a big limiting factor for the main audience of clamp meters (electricians). AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways). The one detracting factor I noticed was indeed the battery access - the threaded screws are a huge turnoff, especially for electricians that will put it to more use, since they don't carry two instruments to a job but only one that does everything.

I would get one if it is priced competitively, but the UT210E is indeed hard to beat for the electronics hobbyist.

[AVGresponding]

(...)
Ok, that's the end.   I gave the video a thumbs up.  Meter seems alright but isn't something I would have a use for.   

I think the meter might be alright as well with protection well above your average chinese product, but the fact the rotary switch is in the center and not on the side is a big limiting factor for the main audience of clamp meters (electricians). AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways). The one detracting factor I noticed was indeed the battery access - the threaded screws are a huge turnoff, especially for electricians that will put it to more use, since they don't carry two instruments to a job but only one that does everything.

I would get one if it is priced competitively, but the UT210E is indeed hard to beat for the electronics hobbyist.

In my every-day tools I carry a Fluke T5-1000 and a Fluke 87V, as well as a Fluke NCV voltpen. I've also got specialist clamps for harmonics measurement, and earth spike testing, and a Fluke 1653 for installation testing. I have no issues carrying all these as and when I need them.   

I can have 150kg or so of tools in my car sometimes, having an all-in-one meter just isn't even on my radar.

[NoMoreMagicSmoke]

AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).

I have an Ideal branded clamp meter (Pretty sure it's actually a Uni-T  ). And they have this really neat dual display. I was expecting it to be gimmicky, but I have used the display on the end of the meter often.

[rsjsouza]

AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).

I have an Ideal branded clamp meter (Pretty sure it's actually a Uni-T  ). And they have this really neat dual display. I was expecting it to be gimmicky, but I have used the display on the end of the meter often.

That is pretty neat indeed and I can see its practical aspects.

Although I wonder if it weakens the housing.

I tried to find the OEM but to no avail. I tried CEM, Mastech, Uni-T and Appa.

[NoMoreMagicSmoke]

AFAIK the vertical reading tends to be preferred by this audience as well (in contrast to sideways).

I have an Ideal branded clamp meter (Pretty sure it's actually a Uni-T  ). And they have this really neat dual display. I was expecting it to be gimmicky, but I have used the display on the end of the meter often.

That is pretty neat indeed and I can see its practical aspects.

Although I wonder if it weakens the housing.

I tried to find the OEM but to no avail. I tried CEM, Mastech, Uni-T and Appa.

It looks like they did the housing pretty well. There is additional plastic ribbing to reinforce the display and input jacks.

I can't say for sure who the OEM is, but the interior build looks suspiciously similar to my Uni-T 210e. It appears to be (the scratched off the label) the same DM1106 controller chip. If they weren't made by the same OEM, they appear to have been based off the same reference design.

[joeqsmith]

Looks like they used two 5mm PTCs in series rather than adding the surge rated resistors we commonly see.   

[NoMoreMagicSmoke]

Looks like they used two 5mm PTCs in series rather than adding the surge rated resistors we commonly see.   

If you are talking about that Ideal meter, then yup... they used two PTC in series (Uni-T style) instead of the surge resistors.

Interestingly, I did look it up and it has a legit UL certification.

[joeqsmith]

Non-destructive testing of the Keysight U1282A.   

[tautech]

LOL, frozen KS !
Would you like ketchup with that Sir ? 

[joeqsmith]

LOL, frozen KS !
Would you like ketchup with that Sir ? 

Brymen specs that 789's operating temperature from -20C  to 55C.  They spec the BM869s from 0 to 45C.  Both seems to have no problems even as low as -40.   I was surprised when the Keysight's internal temp was back up to just under -20C and the meter was still having some problems.   Keysight specs the U1282A's operating temperature from -20 to 55C, just like the Brymen BM789. 
 
Of course, none of these companies provide anything as far as chemical compatibility and some may suggest that these solvents are not something a meter would normally get exposed to.  I was glad the LCD's plastic lens wasn't damaged like the ANENG meters but was disappointed to see the lettering so easily removed. 

I don't think the slow autorange will surprise anyone.  Dave showed how bad it was during his review and commented on it, which is why I was so surprised to see it used in the 121GW.  You could see they tried to improve the 121.   

***
Add KS specs.

[joeqsmith]

That Keysight U1231A was damaged beyond repair at 5kV 100us FWHH 2 ohm source.  The same level that sent the UNI-T UT139C to the recycle bin.  What level will take out the U1282A?  Add your vote.

***
I like when things repeat and expect it to fail at the same level the previous Keysight was damaged at.   

[NoMoreMagicSmoke]

That Keysight U1231A was damaged beyond repair at 5kV 100us FWHH 2 ohm source.  The same level that sent the UNI-T UT139C to the recycle bin.  What level will take out the U1282A?  Add your vote.

***
I like when things repeat and expect it to fail at the same level the previous Keysight was damaged at.   

Since the 1231 failed near the CATIII600 6k transient its rated for I expect the 1282 to be near it's CATIV600v rating of 8k.

[Fungus]

What about some lighter solvents like IPA? I don't often use racing fuel on my bench but the IPA comes out quite often.

Then there's the acetone ... I try not to use that one the bench though.

I expect acetone would make a mess of just about any meter but these are supposed to be tough and "industrial". Maybe try it on some of the less important lettering. 

[floobydust]

Last winter I needed to measure battery voltage on a friend's SUV at -35°C (-31°F) before giving it a boost.
Fluke I don't use on cars because it gets banged up and oil/dirt on it. Well, car toolbox has ANENG AN8008 and... it lasted about 1 minute!
First the rotary switch was making bad contact and took a few spins to stop that, then the push buttons got stiff and stayed stuck down, then the PVC test leads got rock hard. I was hoping only the LCD would freeze lol. It went pretty badly. I was surprised to see how many aspects failed, I've never had a multimeter crater like that.
I think low temp testing needs to go beyond the LCD fluid freezing. The mechanical - pushbuttons and rotary switch crater too.

[joeqsmith]

That Keysight U1231A was damaged beyond repair at 5kV 100us FWHH 2 ohm source.  The same level that sent the UNI-T UT139C to the recycle bin.  What level will take out the U1282A?  Add your vote.

***
I like when things repeat and expect it to fail at the same level the previous Keysight was damaged at.   

Since the 1231 failed near the CATIII600 6k transient its rated for I expect the 1282 to be near it's CATIV600v rating of 8k.

Considering that none of what I show follows IEC standards or has anything to do with the CAT ratings of the meters, seems like as good a guess as any.    The waveform from the newer generator has a 100us FWHH and only about 20J so the current will roll off fairly fast by comparison.   If it makes it to the higher voltage generator, that uses a 50us FWHH and is even lower energy.   Still....  how much energy does it take to damage a SOT23?

[tautech]

That Keysight U1231A was damaged beyond repair at 5kV 100us FWHH 2 ohm source.  The same level that sent the UNI-T UT139C to the recycle bin.  What level will take out the U1282A?  Add your vote.

***
I like when things repeat and expect it to fail at the same level the previous Keysight was damaged at.   

Well if it fails we know why:
For professional and industrial use only.