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 1149565 times)

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Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3300 on: April 09, 2019, 10:46:13 pm »
I plan to use that poor man's vibration table as part of my testing.   I'm sure those speakers were not designed for what I am doing with them....

Ever heard of buttkicker transducers? Might be just the ticket if those speakers aren't sufficient...  thebuttkicker.com

LOL!!! I have and looked at them.  We were having a big laugh a few weeks ago while watching some of the kids with their 5 alternators driving their sound systems.   This is when we saw the buttkicker.    A friend of mine dropped off a large bass driver that I am considering.   It has a built-in amplifier but it appears it's not DC coupled.    When I eventually release the next video, people will get a better idea about the tests and maybe provide some useful feedback.    It's maybe another week out.

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #3301 on: April 10, 2019, 09:35:03 am »

To rent time at a lab and have a product certified I would imagine is in the order of $20,000 or so USD.   I really don't see that as being an option.  Even if we didn't certify them, the rental costs would far exceed what I would be willing to spend.   The we have the problem that I am not really interested in seeing the meters pass their safety standards or not.  A lab like this will have generators specifically for running the IEC standards which is not at all what I have been showing.

Opps i should clarify  that the option was intended to the viewers , not for you to check, since you mentioned something about this matter in one or more the videos as a sugestion.

If one can make knowledge flow than it will go from negative to positve , for real
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3302 on: April 10, 2019, 11:34:29 am »

To rent time at a lab and have a product certified I would imagine is in the order of $20,000 or so USD.   I really don't see that as being an option.  Even if we didn't certify them, the rental costs would far exceed what I would be willing to spend.   The we have the problem that I am not really interested in seeing the meters pass their safety standards or not.  A lab like this will have generators specifically for running the IEC standards which is not at all what I have been showing.

Opps i should clarify  that the option was intended to the viewers , not for you to check, since you mentioned something about this matter in one or more the videos as a sugestion.
This is normally preceded by a viewers comment about how I have shown how safe or unsafe a meter is,  which obviously I don't. 

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #3303 on: April 12, 2019, 07:44:04 pm »
And for vibration test on "disks" is IDE or SATA better:?


https://ebay.us/HywXET
If one can make knowledge flow than it will go from negative to positve , for real
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3304 on: April 12, 2019, 10:42:28 pm »
You like the meters that share the current with the voltage? 

Offline Cliff Matthews

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Re: Handheld meter electrical robustness testing.
« Reply #3305 on: April 12, 2019, 10:49:11 pm »
You like the meters that share the current with the voltage?
I don't but $20 is small change. It's almost a pocket meter, IMO.
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3306 on: April 12, 2019, 10:55:39 pm »
I have looked at a lot of low cost meters.  Nothing I have seen outside of the Fluke 101 has held up very well.  I doubt this meter, based on your picture would do very well in my tests unless there is something below we are not seeing. 

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #3307 on: April 12, 2019, 11:08:39 pm »
well they don't last very long when memory gets blanked :P "There goes the fuse." The shape of that meter looks like a slim HDD ,. , not a roboto style .and fragile , overpriced.

Point is that meters specially those cheap with lots of trimming pots will have a bad day in the vibration tests. 
If one can make knowledge flow than it will go from negative to positve , for real
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3308 on: April 13, 2019, 12:00:07 am »
I best not shake my Mastech meter then.  I think it has more pots than any of my working handheld meters.   

Offline mqsaharan

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Re: Handheld meter electrical robustness testing.
« Reply #3309 on: April 13, 2019, 09:44:04 am »
I best not shake my Mastech meter then.  I think it has more pots than any of my working handheld meters.

Please do include at least one multimeter of your choice with pots for calibration.
 

Offline Fungus

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Re: Handheld meter electrical robustness testing.
« Reply #3310 on: April 13, 2019, 10:09:54 am »
I best not shake my Mastech meter then.  I think it has more pots than any of my working handheld meters.

Please do include at least one multimeter of your choice with pots for calibration.

In my amateur imagination there's a huge difference in vibration resistance between single turn and multi-turn (worm-gear) pots, it would be good to test that.

Do any handheld multimeters use these for adjustment?



« Last Edit: April 13, 2019, 10:14:59 am by Fungus »
 

Offline stj

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Re: Handheld meter electrical robustness testing.
« Reply #3311 on: April 13, 2019, 02:13:42 pm »
UT-61E uses those - i suspect they shift if you hit them hard enough - there is lash when you change direction ajusting them.
 

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #3312 on: April 13, 2019, 02:21:21 pm »
Does the masteech has many pots as this ut204A? It looks all condensed for fitting the damn 9V battery.

« Last Edit: April 13, 2019, 02:23:05 pm by malagas_on_fire »
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Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3313 on: April 13, 2019, 02:39:29 pm »
The UNI-T UT61E I have used a 10 turn pot to trim the reference.   I had replaced it with a part from Bourns when trying to improve it's temperature drift.    Another meter that uses one is the Extech EX540 / CEM DT9939

I have seen several posts mentioning the problems with the UT61E loosing accuracy over time and some assume it has to do with that 10T pot.   I mentioned to you at one point about buying some pots and doing your own drop test.   I think something like this may still be a better approach.   Basically mounting various pots to a board, setting them to their center, measuring them.  Then drop them or run a sweep. 

I have a few meters that have not gone to the recycle yet that I could strip the pots from to run a test like this. 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3314 on: April 13, 2019, 02:49:43 pm »
Does the masteech has many pots as this ut204A?
It appears so.   

Online 2N3055

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Re: Handheld meter electrical robustness testing.
« Reply #3315 on: April 13, 2019, 03:41:06 pm »
What I saw on UT70C is that trimpot has too much of the adjustment range. Replacing it with combination of fixed resistors and much smaller trimpot would make much more stable in that regard.
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3316 on: April 13, 2019, 04:07:16 pm »
What I saw on UT70C is that trimpot has too much of the adjustment range. Replacing it with combination of fixed resistors and much smaller trimpot would make much more stable in that regard.
I have seen others post that as well.   The two UT61E's I looked at, came with 2K trimmers.  When I measured them, they were both set below 1K.   So I replaced mine with a 1K.   I was only looking to improve the temperature drift, which this change did nothing to help.   

I still check this meter from time to time and have not seen any sort of trend with it. 


Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3317 on: April 13, 2019, 08:32:09 pm »
I have a few meters that have not gone to the recycle yet that I could strip the pots from to run a test like this.

Most of the meters I look at now do not have trimmers.   

Online 2N3055

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Re: Handheld meter electrical robustness testing.
« Reply #3318 on: April 13, 2019, 08:47:12 pm »
Most of the meters I look at now do not have trimmers.
Not for calibration, but they still might have frequency response trim in AC path..
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3319 on: April 13, 2019, 09:06:28 pm »
True.  The caps on that test board are for that.   I would imagine there are very few people who bounce their meters around that get too concerned with their -3dB point.  :-DD     I think the Fluke 17B+ had a single trimmer for the temperature. 

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #3320 on: April 13, 2019, 09:48:31 pm »
Indeed it as a trim pot the 17B+ :P Maybe a later add-on on this line of meter .

https://youtu.be/DvC5woDYGd4?t=590
If one can make knowledge flow than it will go from negative to positve , for real
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3321 on: April 13, 2019, 10:35:26 pm »
Anymore even the free HF meter no longer has a trimmer.   

I thought I had saved the parts from my 61E mods, but no luck.  Maybe after I release the next video (won't be much longer), Fungus can chime in if he thinks its a hash enough vibration test or not.   There's no weight to them and they seemed tight when I went to set them to their center positions.  Hard to believe they will move much unless I strike them with a hammer...

Offline stj

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Re: Handheld meter electrical robustness testing.
« Reply #3322 on: April 14, 2019, 11:16:48 am »
a real world test would be dropping them down some stairs, / a liftshaft(only 1-2floors)
or somehow fixing it to an engineblock and running it for a day.
 

Offline joeqsmithTopic starter

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Re: Handheld meter electrical robustness testing.
« Reply #3323 on: April 14, 2019, 12:16:07 pm »
Dropping it from the roof onto concrete would similar to dropping a feather and watching it float.    :-DD   

Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #3324 on: April 14, 2019, 02:26:04 pm »
I may eat my hat later, but I suspect the smaller the trimmer, the less susceptible to a constant vibration it would be.

Obviously, if the equipment is subjected to a direct multi-G impact (from a fall), then I suspect the most fragile parts would be more susceptible to damage.

Oh, well... Let's wait for the video.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

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...
 


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