Handheld meter robustness testing

[joeqsmith]

Sorry for the late reply. It's been a long day
....
Thanks for sharing these. The glitch looks similar to what I experienced before on a Keithley 2700. Other than that the drift doesn't look so bad. Definitely better than my Gossen calibrator. Did you connect the resistor directly to the banana socket?

I ran the battery life test tonight and as promised, I tried it in both DCV and resistance modes.   With the 40ohm load, I was able to lower the battery voltage until the meter turns off without any change in the measurement.  The same was true with a DCV source.    I have seen this be a problem before so didn't hurt to check.   

I have some other tests I want to run before we start the destructive testing so if there is anything else you would like me to look at, let me know.

We had gone through some simplified battery life tests before and I show the numbers below including the U1282A
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013

Thank you for that reminder.  I will use that when I make the next segment and compare it against the data I collected.   

[Trader]

We had gone through some simplified battery life tests before and I show the numbers below including the U1282A
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013

Your tests are impressive, I wonder why did you find half of the time informed in the datasheet:

Keysight U1273A: up to 60 hours vs 33.33h
Keysight U1282A: up to 800 hours vs 377.4h

BTW, these OLED DMMs have terrible battery life.

[rsjsouza]

We had gone through some simplified battery life tests before and I show the numbers below including the U1282A
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013

Your tests are impressive, I wonder why did you find half of the time informed in the datasheet:

Keysight U1273A: up to 60 hours vs 33.33h
Keysight U1282A: up to 800 hours vs 377.4h

BTW, these OLED DMMs have terrible battery life.

Trader, the tests we did (joe also did similar tests a few posts before mine) were a linearization of a typical battery behaviour. The simple quotient between a nominal value for the battery capacity (which may vary between brands and models) and the current consumption are more optimistic than a real battery. For example, for the UT61E the cutoff voltage of just 2,3V (which yields the 305h) is unrealistic as the meter wouldn't start at all since it would throw a beep that draws much more current than the battery would be capable of supplying.
Silent meters such as the U1282A could potentially power on, but a move to the ohms range would probably drain more than the battery could supply (0,975V per cell is borderline a cliff).

So, expect these simulations/tests to be more than one could obtain from these meters. The "up to" is fundamentally misleading if not provided with the test conditions (including the battery brand and mfg year).

[joeqsmith]

This post explains the setup.

https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2081572/#msg2081572

Interesting as you talk about the Fluke 101 compared with the U1289A.   Maybe Keysight overstated the battery life?

[Fungus]

Maybe Keysight overstated the battery life?

It wouldn't be the first thing they've overstated. 

Also, it is mechanically quite robust (Dave went through a canyon with it)

They may be waterproof but are they robust?

This other Keysight meter didn't do too well:

[joeqsmith]

Certainly the switch was a poor choice and electrically it was not very robust.   Your Fluke 101 would run circles around it.

Odd, it looks the BM869s is reading 1.03 while the BM789 is 1.08.  Notice anything funny with that Keysight meter?   I've had that BM869s down to -40C before.   Let's see how the Keysight meter likes it because after all, it's spec'ed lower than the Brymen.   

Poor meters have to earn my respect.

***
Yes, I know -40 is the crossover.  It's also what I used to design for. 

[joeqsmith]

Brymen owner's already know how their meters perform but you Keysight fanboys will have to wait.  That's a 1mV signal from my Fluke standard.

[Trader]

This Brymen 869 has no changes, right?  Why did they put Operating Temperature "0°C to 45°C" in the datasheet?

[rsjsouza]

Brymen owner's already know how their meters perform but you Keysight fanboys will have to wait.  That's a 1mV signal from my Fluke standard.

Is this the display or the meter itself? It would be interesting to see if it comes back to life if the temperature is gradually raised back to its specified -20ºC.

This Brymen 869 has no changes, right?  Why did they put Operating Temperature "0°C to 45°C" in the datasheet?

Although the meter is still working under these conditions, the apparent underspec might be met if the meter is pushed towards its operational range (1kV at CAT III or CAT IV environment).

[rsjsouza]

Also, it is mechanically quite robust (Dave went through a canyon with it)

They may be waterproof but are they robust?

Dave did not only put it through waterproof tests, but many more:

https://www.eevblog.com/forum/blog/eevblog-868-keysight-u1282a-multimeter-torture-test/

[joeqsmith]

This Brymen 869 has no changes, right?  Why did they put Operating Temperature "0°C to 45°C" in the datasheet?

Why would CEM spec their frequency counter to 100MHz when I've shown it working above 150?   Of course I can't speak for Brymen or any other company.   I did gain some respect for CEM surpassing what they state in their datasheet by a large margin and after running the BM789 down to -40C and seeing how well it tracked, they too continue to gain my respect.   

Maybe you could answer why would a viewer call Brymen owner's "pussies" then withdraw it?   Maybe you too are looking for a little respect for your expert opinions?   

[joeqsmith]

Brymen owner's already know how their meters perform but you Keysight fanboys will have to wait.  That's a 1mV signal from my Fluke standard.

Is this the display or the meter itself? It would be interesting to see if it comes back to life if the temperature is gradually raised back to its specified -20ºC.

I am guessing you are referring to the Keysight LCD where I blanked out the LCD.   Don't worry, the next video segment will show it all.   

Dave did not only put it through waterproof tests, but many more:

Very true and watching Dave abuse the meter's mechanically, as a EE was this is partly what started me looking at how robust they were electrically.   That and the dataless fanboys.   

I have had the function switches fail which is why I started running that 50,000 full rotation test.  This is something I would have expected Dave to do, but it takes time to setup.   In the case of that last Keysight meter though, it was all over after a few thousand cycles.  There were no more audible clicks coming from my lab as the Keysight went into stealth mode. 

[Fungus]

This Brymen 869 has no changes, right?  Why did they put Operating Temperature "0°C to 45°C" in the datasheet?

Although the meter is still working under these conditions, the apparent underspec might be met if the meter is pushed towards its operational range (1kV at CAT III or CAT IV environment).

That's 100% speculation.

(and also contains an unfounded insinuation that a Keysight wouldn't do that even though it has a lower CAT rating than the Brymen)

[Trader]

Maybe you could answer why would a viewer call Brymen owner's "pussies" then withdraw it?   Maybe you too are looking for a little respect for your expert opinions?   

The only thing I can say is that YOU are Destroying your review with So MUCH BIAS against Keysight and in Favour of Brymen, in fact, Brymen sends free DMMs to you!

I would suggest you try to be less passionate and more impartial, I know that many tricks can be done to make up for a result, remember the "Volkswagen emissions scandal" (aka "Dieselgate", "Emissionsgate")?

I'm not saying this is a "Brymengate", but all your comments expose a hating against Keysight since the beginning, this gives a strong discredit to your review.

BTW: the Keysight U1282A specs says: "-20°C to +55°C", not -40C; and Brymen 869s datasheet says "0°C to 45°C", so I guess they never tested that, just put a conservative value, OR, there is something else...

[Grandchuck]

Joe is one of the most unbiased and methodical reviewers out there.

[Fungus]

This Brymen 869 has no changes, right?  Why did they put Operating Temperature "0°C to 45°C" in the datasheet?

The obvious answer is that their specs are conservative and leave some margin. I'm not aware of any tests where Brymen meters have underperformed.

OR, there is something else...

Feel free to post any evidence/findings here.

Meters in this thread have to earn their respect, nothing is given for free.

[Trader]

I don't disagree, I watched several reviews and read several posts from him.

But, here in this thread, for me, it's clear he have some prejudice against Keysight, he said that they don't care about his emails, and he is making a Storm to any issue.

My opinion is that this behavior should be avoided, think about a judge taking a side during the middle of the judgment.

Would be better a partial review, and let the people decided about.

[2N3055]

Next episode:

[joeqsmith]

Maybe you could answer why would a viewer call Brymen owner's "pussies" then withdraw it?   Maybe you too are looking for a little respect for your expert opinions?   

The only thing I can say is that YOU are Destroying your review with So MUCH BIAS against Keysight and in Favour of Brymen, in fact, Brymen sends free DMMs to you!

I would suggest you try to be less passionate and more impartial, I know that many tricks can be done to make up for a result, remember the "Volkswagen emissions scandal" (aka "Dieselgate", "Emissionsgate")?

I'm not saying this is a "Brymengate", but all your comments expose a hating against Keysight since the beginning, this gives a strong discredit to your review.

BTW: the Keysight U1282A specs says: "-20°C to +55°C", not -40C; and Brymen 869s datasheet says "0°C to 45°C", so I guess they never tested that, just put a conservative value, OR, there is something else...

All I am doing is presenting data.  You may not like it and feel your only option is to resort to name calling.  While childish, it's fairly common.   I've said how my transient generators are not intelligent and don't care what is connected to them.  There is no bias.  The same for my other tests.     

Early on in this thread I made my hatred of Fluke clear and provided background on why.  People would still accuse me of being a fanboy of Fluke.      If it had not been for Fungus suggesting I look at the 101, I would have never owned another Fluke.   During the testing, they have earned my respect as they continue to prove themselves.  I will gladly eat crow.  Go back and read the posts when I was looking at that Gossen Ultra.  Talk about a witch hunt (I think was what one member was calling it.). 

CEM data sheets show 100MHz for their counter, not 150MHz.  I guess they never tested it.    Keysight U1282A datasheet also shows 100MHz and they can't achieve half that.  I guess they also never tested it!       That's fine.  As I said, I push these meters.  If you like unboxing, 5 star reviews, to feel good about your purchases, look elsewhere. 

Indeed, it's well documented that after buying my BM869s and explaining to Brymen the tests I was running, they became very interested in knowing the outcome.   They offered to repair or replace the meter if I were to damage it during the transient tests.  In the end, I repaired it.  I also bought Dave's rebranded Brymen.   That meter has yet to be damaged.    I then asked Brymen some questions about their automotive meter and because they are hard to get here in the USA, they offered to send one.  At the same time, I mentioned the testing I was doing on the switches and how I was thinking about running the BM869s.   They provided details about their in-house testing along with some video clips (which I included in my videos).  They offered to provide a second BM869s specifically to run that test.  Which I did.   Then Dave posted about selling a new Brymen meter.   Hearing that, I contacted them about testing it the prototype.  This led to testing the 789 prototype as well.   

While Brymen has proven to have an interest in seeing how their products stack up, I don't see that with other brands.   While UNI-T and anther large company contacted me about making reviews,  once I explain what I am doing, they decline.   Again, this is nothing new and all documented.   While I would have some concern about getting products through these channels,  if Gossen for example approached me about their improvements to the Ultra (now Prime), I would gladly repeat the tests.   I would do the same if UNI-T wanted to repeat the tests on an improved UT181A.   Both of those products would be worth investing the time into.     Keysight, like any other brand will earn it's place based on how they perform.

"Volkswagen emissions scandal"  We had an youngster at work who wanted to lecture me about this case.   I gave them a history lesson so they wouldn't be so ignorant the next time they approached the topic.   

[Chance92]

"Volkswagen emissions scandal"  We had an youngster at work who wanted to lecture me about this case.   I gave them a history lesson so they wouldn't be so ignorant the next time they approached the topic.

Maybe it's a bit off-topic but I am quite interested to know more about this from your point of view. What is this history lesson you were talking about?

[Trader]

earn[/b] their respect, nothing is given for free.

This is an interesting situation:

First, the specs says -20C, not -40C, no reason for criticizing Keysight, in fact I didn't see a picture of -20C.

Second, some Batteries (types/brands) stop working in low temperatures. Maybe using another battery, the result could be different for both DMMs.

Third, these "issues" like 100MHz, -40C, etc are not so important, in fact majority DMMs frequency counter are up to 1 or 10MHz.

The Log glitch is small, but relevant, maybe could fixed via software. But it's so clear that could be easily removed from the dataset, as an outlier.

This threading is becoming less technical because of reviewer impartiality, hatering against Keysight, and this issue compromise the review.

[Fungus]

First, the specs says -20C, not -40C, no reason for criticizing Keysight, in fact I didn't see a picture of -20C.

So ... you don't actually know if it works at -20C or not? 

Two of Keysights published claims for this meter (frequency and battery life) have already been shown to be false in real tests. Both were less than half the published figure.

How much faith are you still putting in their datasheet?

The Log glitch is small, but relevant, maybe could fixed via software. But it's so clear that could be easily removed from the dataset, as an outlier.

Huh? Logging is usually used to find glitches. How will you distinguish between a momentary power glitch and an "outlier"?

[joeqsmith]

"Volkswagen emissions scandal"  We had an youngster at work who wanted to lecture me about this case.   I gave them a history lesson so they wouldn't be so ignorant the next time they approached the topic.

Maybe it's a bit off-topic but I am quite interested to know more about this from your point of view. What is this history lesson you were talking about?

  I had 20+ years in automotive before changing careers.  Much of our government's involvement is transparent and on-line.  Rather than my point of view, try Google. 

[joeqsmith]

Huh? Logging is usually used to find glitches. How exactly will you distinguish between a momentary power glitch and an "outlier"?

I can't say why people usually log data but that fact the we have seen the Keysight U1282A  is not reliable and the glitches could cause someone to waste time trying to find the source, it's best to be aware of it. 

Not directed towards fungus, but in general if seeing meters ran outside their published specs bothers you, I suggest finding threads better suited for your interests.   Again, I typically push the meters to failure.  Most are damaged beyond repair and are recycled.   My goal is to see how electrically robust they are when ran against a standard set of conditions.   After so many years, I expect the diehards know what's what.   

[AVGresponding]

The concerning thing for me is as Fungus has mentioned, the performance does not match the specifications in at least two areas, and the strange thing is it's in things most people couldn't care less about. Who cares if a handheld DMM can measure to 30MHz or 100MHz? I don't, it's little more than a gimmick. If I'm making a serious frequency measurement I'm using a counter and/or a scope.

I care that they chose to claim better performance than they deliver; it's out of character for a premium brand, but fits with the corporate bean counter culture that seems to have ousted the engineering culture at HPAK.