Handheld meter robustness testing

[Trader]

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

You are right, I was thinking about that resistance log.

[armandine2]

 . . . my feeling regarding someone taking the time, to do a proper test of a meter, is it's great - and the manufacturer surely should've done at least the same, if not much more. 

ed - I voted for the Keysight - as a potential purchaser of such an expensive piece of TE - it seemed prudent.

[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.

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.

Indeed it is. I wasn't sure if the meter had died or the display had somehow just faded away.
   

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. 

Indeed. What you showed with the smaller Keysight's rotary switch (and could potentially repeat in this one) is that a chain is only strongest on its weakest link. The U1282A might survive drops and being run over by cars, but the switch, a PTC or fuse might be its Achilles' heel. What matters for someone might be insignificant for someone else. That is why tests are important.

[rsjsouza]

Passions are running high around here...

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.

That is the reason why I used the words apparent and might. They give the correct measurement of uncertainty that the subject requires, as I don't work for Brymen (nor for one of their testhouses) to be absolutely sure. 

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

I can't make any assessment on what you read between the lines, Fungus. Give it a rest and don't assume I am a Keysight fanboy. 

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.

So, I am the one speculating, huh?

[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.

Working on the editing tonight and took a screen shot of your data.  When I compared the nominal with what I collected, we were very close.

[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.

Indeed it is. I wasn't sure if the meter had died or the display had somehow just faded away.

Just a quick erase with Paint.  The results were actually very surprising if you haven't looked at yours.  About 4 hours of testing boils down to 6 minutes of video.   

My plan is to run all the non-destructive tests for this next segment, then move onto the transient tests and finally finish up with the switch testing.  If there is anything left of the meter, we can open it up for any other destructive tests people may want to see.     

[joeqsmith]

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.
...
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.

True, they don't actually state the data logger is glitch free or that it works at all.  So, no embellishment going on there.   Of course, there may be a level of customer expectations that they didn't consider.   

[Fungus]

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.

I think a lot of people care about battery life. It was one of the mentioned when I asked why people would buy this meter.

Keysight also seems to think it's important: It's number three on the "key features" list in the brochure (right after counts and DC accuracy) and it gets the very first paragraph in the blurb.

See page 2 of this: https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf

Prolonged battery life and rugged
"The last thing you want is for your tools to run out of juice when you need it the most. The U1280 series
handheld DMMs lets you carry out test and measurements over a longer duration than ever before. With
up to 800 hours of battery life, you have a handheld DMM which works for a long time minus the hassle of
battery change, especially useful for frequent usage or prolong testing. Put your battery concerns behind
and fully focus on your work at hand, as it should be for maximum productivity."

(I guess they do say "up to". Maybe you can do it with fancy lithium batteries or something... )

[joeqsmith]

We had gone through some simplified battery life tests before and I show the numbers below including the U1282A

Could you please go back and retest your MaxFunc readings?   I measured higher back light current than you show which I guess isn't too big of a surprise but I wonder what you did to get the MaxFunc up to 7.1mA? 

When I have taken this data, its always without the leads attached.  Did you have a load attached?   I just tried it with my other equipment and repeated what I see with my source meter that I normally use.  Everything repeats.  I then tried it with a short in continuity mode with the beeper full on and still could not reach 7.1mA.   It could be the two meters are just that different and maybe they tried to improve the battery life.   I just want to make sure I didn't miss something.   

[rsjsouza]

We had gone through some simplified battery life tests before and I show the numbers below including the U1282A

Could you please go back and retest your MaxFunc readings?   I measured higher back light current than you show which I guess isn't too big of a surprise but I wonder what you did to get the MaxFunc up to 7.1mA? 

When I have taken this data, its always without the leads attached.  Did you have a load attached?   I just tried it with my other equipment and repeated what I see with my source meter that I normally use.  Everything repeats.  I then tried it with a short in continuity mode with the beeper full on and still could not reach 7.1mA.   It could be the two meters are just that different and maybe they tried to improve the battery life.   I just want to make sure I didn't miss something.   

Joe, I can do this later. Regarding the MaxFunc, there might be a chance I was trying with a mode other than continuity (I was fishing for the highest consumption regardless of the mode).

The capacitance mode comes to mind, but I can't be sure at the moment.

[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.

I think a lot of people care about battery life. It was one of the mentioned when I asked why people would buy this meter.

Keysight also seems to think it's important: It's number three on the "key features" list in the brochure (right after counts and DC accuracy) and it gets the very first paragraph in the blurb.

See page 2 of this: https://www.keysight.com/us/en/assets/7018-04867/data-sheets/5992-0847.pdf

Prolonged battery life and rugged
"The last thing you want is for your tools to run out of juice when you need it the most. The U1280 series
handheld DMMs lets you carry out test and measurements over a longer duration than ever before. With
up to 800 hours of battery life, you have a handheld DMM which works for a long time minus the hassle of
battery change, especially useful for frequent usage or prolong testing. Put your battery concerns behind
and fully focus on your work at hand, as it should be for maximum productivity."

(I guess they do say "up to". Maybe you can do it with fancy lithium batteries or something... )

Up to a point, I suppose. I mean, if it was 6 hours, I'd be quite displeased, but when you are talking about the difference between say, 800 and 400 hours, no, I really don't care, and I'd be quite surprised if it was a deal maker/breaker for anyone else. I have spare batteries, both at home and at work.   

[Trader]

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

The U1282A specs say -20C, not -40C.

Some Batteries (material/brands) stop working in low temperatures.

I wonder if removing the batteries from all DMMs and just using a power supply, how would they perform?

[joeqsmith]

We had gone through some simplified battery life tests before and I show the numbers below including the U1282A

Could you please go back and retest your MaxFunc readings?   I measured higher back light current than you show which I guess isn't too big of a surprise but I wonder what you did to get the MaxFunc up to 7.1mA? 

When I have taken this data, its always without the leads attached.  Did you have a load attached?   I just tried it with my other equipment and repeated what I see with my source meter that I normally use.  Everything repeats.  I then tried it with a short in continuity mode with the beeper full on and still could not reach 7.1mA.   It could be the two meters are just that different and maybe they tried to improve the battery life.   I just want to make sure I didn't miss something.   

Joe, I can do this later. Regarding the MaxFunc, there might be a chance I was trying with a mode other than continuity (I was fishing for the highest consumption regardless of the mode).

The capacitance mode comes to mind, but I can't be sure at the moment.

Looks like it may have been diode check with a short to enable the beeper.  This gets me very close so I think we are all set.   

[TheDefpom]

With the timing, I still think it's damage control.   

I actually approached Daniel about 3 or 4 months ago about doing a multimeter review, I had to wait a while before it could be sent due to component shortages.

[joeqsmith]

With the timing, I still think it's damage control.   

I actually approached Daniel about 3 or 4 months ago about doing a multimeter review, I had to wait a while before it could be sent due to component shortages.

I did not watch both parts and only skimmed the one.  Did you run temperature, battery life, data logging on the meter?   Any other odd tests that gave you trouble that you would like to see if I can replicate?   

[joeqsmith]

Will we see history once again repeat itself??       I have changed the brand name for your viewing pleasure. 
 

When I first listened to the video you came across as strongly anti Keysight so that appears to make you biased against the company straight away. Every multimeter has to be treated independently so it does not depend on the series or company it is from. You have said this yourself! There is a danger that you will stereotype a company because it does not at first live up to your own standards. "Saving your skin" is just saying that viewers will treat you with more respect and not pass you off as an anti Keysight tester.

I don't understand the point of testing these meters beyond their specifications. It says right on the front of the Keysight: "1000v" with CAT IV; why go beyond this?

These test are irrelevant over what is rated, is like you smash a car at 2 mach and say "ehh car not good, unsafe, bla bla" whats the point of using a meter over the rated point???

Why did you treat the Keysight unfairly?

[NoMoreMagicSmoke]

I don't understand the point of testing these meters beyond their specifications. It says right on the front of the Keysight: "1000v" with CAT IV; why go beyond this?

These test are irrelevant over what is rated, is like you smash a car at 2 mach and say "ehh car not good, unsafe, bla bla" whats the point of using a meter over the rated point???

Why did you treat the Keysight unfairly?

I read this as a challenge that you need to up your transient tester to actually be able to output 6000A at 12KV with a 2Ohm source impedence. 

I mean the last thing you want to do is treat the Keysight unfairly and not to it's rated spec. 

[Fungus]

Some Batteries (material/brands) stop working in low temperatures.

So you keep saying...

Look closer though: The reason there's no display on the Keysight at -40C is that joe blanked it out using Windows Paint to keep us in suspense.



All the "-40C" image shows is that the Brymens are still working, it doesn't say anything about the Keysight.

[joeqsmith]

 

I would hate the Keysight fanboys to think their meter turned off because of crap batteries so here's a better view of the U1282A...   

I don't understand the point of testing these meters beyond their specifications. It says right on the front of the Keysight: "1000v" with CAT IV; why go beyond this?

These test are irrelevant over what is rated, is like you smash a car at 2 mach and say "ehh car not good, unsafe, bla bla" whats the point of using a meter over the rated point???

Why did you treat the Keysight unfairly?

I read this as a challenge that you need to up your transient tester to actually be able to output 6000A at 12KV with a 2Ohm source impedence. 

I mean the last thing you want to do is treat the Keysight unfairly and not to it's rated spec. 

I don't think Fungus's poor little Fluke 101 was spec'ed to handle that.   Funny that meter has never been damaged and I don't think I have had it apart.  Then to have another member step up and repeat that 12kV test just to see if I was BSing, using an actual IEC generator from their work place was a pleasure to watch.   Now that's how you review a meter!!   

I have a few more tests I want to run and should have the next segment up this weekend.   

[Trader]

Look closer though: The reason there's no display on the Keysight at -40C is that joe blanked it out using Windows Paint to keep us in suspense.
All the "-40C" image shows is that the Brymens are still working, it doesn't say anything about the Keysight.

Yes, it's hidden. But in the previous post he said:

"Odd, it looks the BM869s is reading 1.03 while the BM789 is 1.08.  Notice anything funny with that Keysight meter?"

And posted an image that seems like "1.451 mV".

As I said, maybe the batteries were weak because of the low temperature, best to use a power supply for all DMMs.

https://www.upsbatterycenter.com/blog/batteries-in-cold/

[NoMoreMagicSmoke]

I don't think Fungus's poor little Fluke 101 was spec'ed to handle that.   Funny that meter has never been damaged and I don't think I have had it apart.

I really like the elegant simplicity of the 101. It's a neat little meter that seems to be far better than it's price would imply!

  Then to have another member step up and repeat that 12kV test just to see if I was BSing, using an actual IEC generator from their work place was a pleasure to watch.   Now that's how you review a meter!!   

You don't happen to have a link to that video do you? I'm very interested in watching!

[joeqsmith]

You don't happen to have a link to that video do you? I'm very interested in watching!

Go to the first page where I created a TOC to help members navigate this thread.  Then find:   "Member Meter Junkie runs a second Fluke 101 on their IEC combo generator at 12KV" 

He mentions it was suggested it should survive 17.   I ran that Fluke 107 to I think 15 before it finally gave in.  Even then it was hardly a scratch.   Think this Keysight will handle that?      

[joeqsmith]

Two of us have measured the dropout voltage and I have provided some data how the meter is stable until it shuts down.   Of course I welcome anyone to step up and repeat any tests I show.   

We need Fungus's Canadian friend to join.  Now there was a Keysight fanboy.  He even made a rebuttal video proving the Keysight's switch would not fail after 10's of thousands of cycles.       I don't recommend anyone going to hunt that one down.  A half hour of expert opinion.    

[Fungus]

...poor little Fluke 101.   Funny that meter has never been damaged and I don't think I have had it apart.

I've had mine apart. It has some big, chunky components inside.



Not bad for a $45 meter.

(Image from this thread: https://www.eevblog.com/forum/testgear/fluke-101-multimeter-teardown/ )

[NoMoreMagicSmoke]

You don't happen to have a link to that video do you? I'm very interested in watching!

Go to the first page where I created a TOC to help members navigate this thread.  Then find:   "Member Meter Junkie runs a second Fluke 101 on their IEC combo generator at 12KV" 

He mentions it was suggested it should survive 17.   I ran that Fluke 107 to I think 15 before it finally gave in.  Even then it was hardly a scratch.   Think this Keysight will handle that?      

Found it but it looks like access to the video has been limited. O well, it sounds like it was pretty boring 

I hope the keysight survives. If only because I want to believe that they live up to their heritage!