Poll

How many cycles will the KeySight U1281A's detent spring last?

0-2000
7 (17.9%)
2k-4k
5 (12.8%)
4k-8k
14 (35.9%)
8k-16k
7 (17.9%)
>16k (most rubust meter ever made)
6 (15.4%)

Total Members Voted: 36

Author Topic: Handheld meter robustness testing  (Read 1149428 times)

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Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #2425 on: March 06, 2018, 01:24:18 pm »
Dave's running a live switch cycle on his second channel.  I watched it for a few minutes.  Tried to calculate the resistance with the formulas shown but looks like its 1.7K ohms the one way  a little better the other.  Guessing I am missing something as I think he said they could only read up to 10 ohms or so.   So much computing power and they resort to sticky notes.   :palm:

He also cleaned off the accumulated dust/debris after every bunch of cycles.  :scared:

If that's fiberglass dust then it's an abrasive, just sayin'.

I don't think it's fiberglass - solder mask more likely. In normal use the meter would be picked up and put down potentially dislodging the dust anyway after every use or so - you cannot replicate normal usage easily. These sorts of test can only ever be a rough guide to wear rate, and you would need to test many to get some sort of average.

I was under the impression that this round of testing was done live, non-stop, 50K half cycles, no cleaning with the shim installed correctly.  I only saw the last few minutes so if you saw him cleaning it again, that's a problem.   If your pulling that out of your ass and don't really know, we should ask Dave.   

I don't need to run more of the same meter to see the difference in wear.   Between the pictures and resistance metric, it's good enough for me.   Some have certainly cut deeper than mask.  Then there is that detent spring, it's not always the contacts that are the problem.       

Then again, I have been told many times that I can't draw a conclusion from the transient tests I run because the sample size is one. 
« Last Edit: March 07, 2018, 12:37:28 am by joeqsmith »
 

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2426 on: March 06, 2018, 01:47:32 pm »
It's held in place by the screws.  It does not appear to spring off the back of the case.  It looks like it was designed to fit flat. There are no clearance issues I see with that would prevent it from sitting flat.  I see no reason for it to be bowed other than poor quality control.

So basically the metal tabs in the middle of the shield just weren't in their PCB holes?

Oh, dear.
« Last Edit: March 06, 2018, 01:49:33 pm by Fungus »
 

Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2427 on: March 06, 2018, 03:50:51 pm »
I foresee the used test gear market will start categorizing 87Vs between pre- and post- a specific serial#... That or photographs of the back of the meters will become almost mandatory.

IMHO every reaction is sparked by a previous action - as I said before, due to the amount of competition on the 20k count segment I honestly believe the 87V's sales figures can't support the margins it once had.
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Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2428 on: March 06, 2018, 04:36:04 pm »
IMHO every reaction is sparked by a previous action - as I said before, due to the amount of competition on the 20k count segment I honestly believe the 87V's sales figures can't support the margins it once had.

Sure, but they're not lowering the prices and I can't believe the cost of manufacturing them is going up.

This is just bean counting of the very worst kind. John Fluke must be doing about 12 RPM right now.
 

Offline floobydust

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Re: Handheld meter electrical robustness testing.
« Reply #2429 on: March 07, 2018, 01:12:40 am »
After seeing the bent shield in my brand new Fluke 87V, a member with a slightly older 87V took theirs apart and provided me with this picture.  I had hoped the meter I received was a one off mistake but it appears they are bending the shield and no one is catching it.  I have not yet done anymore with the 87V and it's still sitting in parts.  The shield looks like it is designed to sit flat.  I can place it flat in the board.   The two tabs seem to be setup correctly.    Maybe they cut their QC staff to make more money?  Maybe it's supposed to be bent?   

Too bad these large companies have no presence in these groups.   If it were Brymen, I would just ask them and based on all my previous experiences with them, would have an answer in a day.  I never found a contact at Danaher/Fluke.

The clearances from shiield to the HV input circuit parts looks bad?
The leads on the MOVs', 1k resistor etc. there should be a insulating barrier ?
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #2430 on: March 07, 2018, 01:35:24 am »
After seeing the bent shield in my brand new Fluke 87V, a member with a slightly older 87V took theirs apart and provided me with this picture.  I had hoped the meter I received was a one off mistake but it appears they are bending the shield and no one is catching it.  I have not yet done anymore with the 87V and it's still sitting in parts.  The shield looks like it is designed to sit flat.  I can place it flat in the board.   The two tabs seem to be setup correctly.    Maybe they cut their QC staff to make more money?  Maybe it's supposed to be bent?   

Too bad these large companies have no presence in these groups.   If it were Brymen, I would just ask them and based on all my previous experiences with them, would have an answer in a day.  I never found a contact at Danaher/Fluke.

The clearances from shiield to the HV input circuit parts looks bad?
The leads on the MOVs', 1k resistor etc. there should be a insulating barrier ?
You know, it does look bad in that picture they sent me.  There's that tab on the backside that should hold it away from the board and I have not looked but I don't think the shield extends down far enough.  That said, nothing says they did not change the shield design.  There meter is older than mine.  This same person has an older version of the meter and they said the shield was made differently in the earlier models.  They said they would provide me with a picture of that one for comparison.  I will post it once I have it.   

It could be a Gossen and have no shield and be unstable as you move your hand near it, expose it to RF, or have relays that change states when exposed to a magnetic hanger.  All preventable with a good shield design.    The things we can learn with a sample size of one! 


Offline EEVblog

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Re: Handheld meter electrical robustness testing.
« Reply #2431 on: March 07, 2018, 04:52:28 am »
Dave's running a live switch cycle on his second channel.  I watched it for a few minutes.  Tried to calculate the resistance with the formulas shown but looks like its 1.7K ohms the one way  a little better the other.  Guessing I am missing something as I think he said they could only read up to 10 ohms or so.   So much computing power and they resort to sticky notes.   :palm:

He also cleaned off the accumulated dust/debris after every bunch of cycles.  :scared:

No I did not.
The latest test was 50,000 cycles with no interruptions. You are welcome to watch the entire 23 hours video once Youtube has finished processing it, assuming it actually can process a 23hr live stream.
 

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2432 on: March 07, 2018, 07:07:51 am »
He also cleaned off the accumulated dust/debris after every bunch of cycles.  :scared:

No I did not.

What happened at the 12 minute mark?



Quote: "A bit of spit on that..."

The latest test was 50,000 cycles with no interruptions.

Fair enough.
« Last Edit: March 07, 2018, 09:02:27 am by Fungus »
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #2433 on: March 07, 2018, 01:05:01 pm »
He also cleaned off the accumulated dust/debris after every bunch of cycles.  :scared:

No I did not.

What happened at the 12 minute mark?

Quote: "A bit of spit on that..."

Fair enough.
Previous test was all.

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #2434 on: March 07, 2018, 01:09:18 pm »
These are the pictures showing the older Fluke 87V shield design.   I would think the stamped shield would be less costly to produce.  I have asked for a picture showing the stamped shield from the backside to see if they changed the profile. 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #2435 on: March 08, 2018, 02:16:42 am »
It appears their older 87V's shield is identical to the one supplied with mine.  It sure looks like their tab was not pushed through the slits when the shield was installed.  It's too bad Fluke reps don't hang out here.  It seems like something they would want to know about, then again, it seems like it has been a problem for a long time so hard to believe the supervisor's and QC are not aware of it.   

Offline IanB

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Re: Handheld meter electrical robustness testing.
« Reply #2436 on: March 08, 2018, 02:30:04 am »
It appears their older 87V's shield is identical to the one supplied with mine.  It sure looks like their tab was not pushed through the slits when the shield was installed.  It's too bad Fluke reps don't hang out here.  It seems like something they would want to know about, then again, it seems like it has been a problem for a long time so hard to believe the supervisor's and QC are not aware of it.

You don't need to test a product for quality if lack of quality does not affect your sales. It's not cost-effective.
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #2437 on: March 08, 2018, 03:03:51 am »
It appears their older 87V's shield is identical to the one supplied with mine.  It sure looks like their tab was not pushed through the slits when the shield was installed.  It's too bad Fluke reps don't hang out here.  It seems like something they would want to know about, then again, it seems like it has been a problem for a long time so hard to believe the supervisor's and QC are not aware of it.

You don't need to test a product for quality if lack of quality does not affect your sales. It's not cost-effective.
True but wouldn't take much more than the line supervisor looking at one and showing the worker how to properly install them.  If their supervisor can't handle something that basic, I would say they have the wrong person in that position.  But it may be cheep labor.  Or maybe unsupervised.  Surly the workers must think, that part should fit flat and maybe I should try and slid that tab into that slit....  Crazy...

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2438 on: March 08, 2018, 01:16:51 pm »
You don't need to test a product for quality if lack of quality does not affect your sales. It's not cost-effective.

Yep. If large corporations are buying these by the truckload without ever looking inside then what's the point? Got a problem? send it back.

Fluke can probably absorb 50% returns under warranty and still make a profit on these things.

(Maybe more: What's the BOM? About $50 I imagine... what's the next most expensive thing after the fuses and the precision resistors? The leads?)
 

Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2439 on: March 09, 2018, 12:18:19 am »
You don't need to test a product for quality if lack of quality does not affect your sales. It's not cost-effective.

Yep. If large corporations are buying these by the truckload without ever looking inside then what's the point? Got a problem? send it back.

Fluke can probably absorb 50% returns under warranty and still make a profit on these things.

(Maybe more: What's the BOM? About $50 I imagine... what's the next most expensive thing after the fuses and the precision resistors? The leads?)

What was the cost to have the custom IC made?  Burden?  Certifications?
If it follows other meters from Fluke, it is probably a MSP430 with clipped JTAG and a custom P/N. I don't recall ever seeing a larger MSP430 ROM masked. If that is correct, the cost for the customization itself is no different than a commercial part, only the volume counts.
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Re: Handheld meter electrical robustness testing.
« Reply #2440 on: March 09, 2018, 01:11:11 am »
If it follows other meters from Fluke, it is probably a MSP430 with clipped JTAG and a custom P/N. I don't recall ever seeing a larger MSP430 ROM masked. If that is correct, the cost for the customization itself is no different than a commercial part, only the volume counts.

I doubt that the front end is something you program with JTAG?  I expect it to be a full custom, mixed mode IC developed exclusively for Fluke, possibly by Fluke.  I doubt it's just a remarked device but I don't know.  We could ask a Fluke rep but they don't seem to hang around the forums. 

Starting to work on Part 4.
Starting to work on Part 4. repairing it again ?  :)
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Offline Cliff Matthews

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Re: Handheld meter electrical robustness testing.
« Reply #2441 on: March 09, 2018, 01:38:57 am »
Ha! Speaking of repairs.. Bigclive just made a video on Fluke recalling the SM100/200/300 plug-in testers. After Joe pops the brains out of this one, me thinks John Fluke Sr will be turning.
 

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2442 on: March 09, 2018, 09:01:09 am »
I doubt that the front end is something you program with JTAG?  I expect it to be a full custom, mixed mode IC developed exclusively for Fluke, possibly by Fluke.  I doubt it's just a remarked device but I don't know.

Design/development costs for the chip will have been recovered a long time ago.

 

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2443 on: March 09, 2018, 09:55:41 am »
It may surprise us and survive everything.   What a twist that would be as it sounds like the majority feel it is just doing to fail the same.  I don't think one person has told me they thought it was going to do well since I started.   What's that tell you.   Surly I have not shaken the confidence of the countless  Fluke 87V fans.     

The eyes of the world are on you, joe.

(...and if it does worse than a 17B+ then something is very wrong)
 

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2444 on: March 09, 2018, 09:59:00 am »
What was the cost to have the custom IC made?
The first batch of ICs would have been very expensive. A $400 price tag was probably justified.

Today? Not so much. I'd be surprised if the chip costs as much as the fuses. It's not a complex chip by today's standards and the R&D was done long ago.

(could any experts add anything here?)
« Last Edit: March 09, 2018, 10:24:19 am by Fungus »
 

Offline stj

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Re: Handheld meter electrical robustness testing.
« Reply #2445 on: March 09, 2018, 11:41:06 am »
if things are like 20 years ago, the most expensive bits may well be the injection-moulded plastic parts!!
that stuff costs a lot because the moulds are a bitch to make, and they dont last forever.
also, the parts must be hand-finished afterwards to get rid of tails and stuff.
 

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #2446 on: March 09, 2018, 12:53:58 pm »
This is the king of meters, why aren't people saying it was all a Fluke and how the 87V is going to surpass every Fluke I have looked at?  Where is the confidence I keep hearing about?   

There's a reason you drew a demon on your zapper...  :popcorn:
 

Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2447 on: March 09, 2018, 06:27:45 pm »
If it follows other meters from Fluke, it is probably a MSP430 with clipped JTAG and a custom P/N. I don't recall ever seeing a larger MSP430 ROM masked. If that is correct, the cost for the customization itself is no different than a commercial part, only the volume counts.

I doubt that the front end is something you program with JTAG?  I expect it to be a full custom, mixed mode IC developed exclusively for Fluke, possibly by Fluke.  I doubt it's just a remarked device but I don't know.  We could ask a Fluke rep but they don't seem to hang around the forums. 

Starting to work on Part 4.
Oh, were you referring to the front end? I was talking about the main processor IC, which years ago it used to be a MSP430 but I didn't keep current with the latest models (thus it could have been morphed into a custom-looking part).
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline Cliff Matthews

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Re: Handheld meter electrical robustness testing.
« Reply #2448 on: March 10, 2018, 02:48:40 am »
Smoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....
:scared: That was bait and you know it..
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #2449 on: March 10, 2018, 03:54:41 am »
Smoke was rolling out of the 87V tonight and I'm not even to the fun stuff yet....
:scared: That was bait and you know it..
Just keeping you in the loop.    I thought people on this forum liked getting the second by second updates....  :-DD   


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