Poll

Are you interested in seeing more handheld meters tested?

This testing is pointless! Please STOP damaging these meters!
3 (6.4%)
 Yes, I would like to more meters tested.
44 (93.6%)

Total Members Voted: 47

Author Topic: Handheld meter robustness testing  (Read 648804 times)

0 Members and 5 Guests are viewing this topic.

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1900 on: September 11, 2017, 11:15:03 am »
Looks like the diode test voltage was lowered.  I lost the CMOS switch twice and had changed the part to higher voltage one and added a TVS to protect it.  Margins were pretty tight but the meter survived after this.  I was hoping they could find a fix as the 15V feature would have been very nice for checking high voltage diodes.
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1901 on: September 11, 2017, 11:22:31 am »
I made a second attempt at modifying the Kasuntest ZT102 to see if I could get it to survive some basic levels from my transient generators.

https://youtu.be/-V9JvFRjL78
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
The following users thanked this post: Jon.C, MacMeter, kalel

Offline Crumble

  • Regular Contributor
  • *
  • Posts: 97
Re: Handheld meter electrical robustness testing.
« Reply #1902 on: September 12, 2017, 09:01:57 am »
Nice one Joe! This must have been a hell of a lot of work. I actually found this one quite captivating. At one point I stopped it, but changed my mind and watched the entire clip because i was genuinly curious how it would end. Nice to see the meter survives now, did the Hioki not break down in a similar way?
 

Offline 3db

  • Frequent Contributor
  • **
  • Posts: 330
  • Country: gb
Re: Handheld meter electrical robustness testing.
« Reply #1903 on: September 12, 2017, 11:16:26 am »
14 KV !! Awesome work Joe.  :-+
Very interesting video.
Appreciate the time and effort you give in order to make these videos.

3DB.
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1904 on: September 12, 2017, 09:59:30 pm »
Nice one Joe! This must have been a hell of a lot of work. I actually found this one quite captivating. At one point I stopped it, but changed my mind and watched the entire clip because i was genuinly curious how it would end. Nice to see the meter survives now, did the Hioki not break down in a similar way?

Yes the HIOKI I ran broke down because of some plastic that was not quite large enough and the meter was not electrically damaged.   This meter was similar in that it was not damaged. 

14 KV !! Awesome work Joe.  :-+
Very interesting video.
Appreciate the time and effort you give in order to make these videos.

3DB.
Well, a solid 10KV anyway.   You want 14KV, you got it.   This was really the goal, get it up to the levels that the most robust handheld meters I have tested survive at.  There is not a lot of science to it but I hope that it shows that its not something that is all that difficult to achieve.  I really see no reason that especially the $100 and up meters will not survive to the levels this modified $15 Kasuntest meter will.   

https://youtu.be/dEwLuiYX5cQ
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1905 on: September 14, 2017, 12:20:36 am »
Someone had requested the dead meters be drop tested. 

https://youtu.be/PYFs9F0scDQ
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
The following users thanked this post: Jon.C

Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 8687
  • Country: us
  • Lots of engineer-tweakable parts inside!
Re: Handheld meter electrical robustness testing.
« Reply #1906 on: September 14, 2017, 12:27:05 am »
Joe, you're really widening your equipment-destroying horizons. Break a leg...er...an instrument!
I TEA.
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 3849
  • Country: ca
Re: Handheld meter electrical robustness testing.
« Reply #1907 on: September 14, 2017, 07:32:35 pm »
I worked for a Telecom manufacturer and they did 1m drop testing on hard floors.
Scared the !Q@#%^@#^ out of me, mechanical engineers go in the lab and start throwing them down. SMACK! Buttons flying everywhere.
Results seemed so variable, if the display hit or the buttons hit first. It was a free-fall standard, but they threw them down to find the design weakness.

The main point was the desk phone would not crack or break under a typical slide off your desk scenario.
 

Offline Crumble

  • Regular Contributor
  • *
  • Posts: 97
Re: Handheld meter electrical robustness testing.
« Reply #1908 on: September 14, 2017, 09:23:18 pm »
A two floor drop and just a few scratches, seems reasonably robust to me. It may be helped by the fact they weigh almost nothing. It does seem that good spring material is difficult to get, i have had issues with fuses not connecting properly in cheap meters.
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1909 on: September 15, 2017, 03:14:08 am »
The three CEM DT9939s. These are 40K count, have an internal RF link and tri-display.  They also have basic features like AC+DC.    A few of us bought the CEM from Ruby Electronics when they were selling them for $120.  I've made a review of them and showed many problems with the meter on the right.   

The meter in the center is from work.  It was just calibrated and turned five years old.  The meter has had a rough life.  I loaned it out once and the person had turned the knob past the dead stop.   A few times it came back with blown fuses.  Then I put it through a fair amount of abuse myself.  People say how they never use their meters about 40 deg C.  This meter has been used above those temps with the RF link.  I've dropped it a few times and you can see how the case has discolored with time from being out in the sun.

We would never have them generate a calibration report for a handheld so I don't have any records on drift.  It has never been aligned and I thought for fun I would compare it against some of my home equipment.   
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
The following users thanked this post: xrunner, Cliff Matthews, 3nigm4

Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 8687
  • Country: us
  • Lots of engineer-tweakable parts inside!
Re: Handheld meter electrical robustness testing.
« Reply #1910 on: September 15, 2017, 04:15:26 am »
Looking forward to the review, Joe. :-+
I TEA.
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1911 on: September 15, 2017, 06:01:36 pm »
Happy Birthday EX540

https://youtu.be/Yih7D23z7vE
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
The following users thanked this post: SeanB, 3nigm4

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1912 on: September 16, 2017, 08:51:00 pm »
I was asked if all I did was add more dope to get the Kasuntest to survive at higher levels without breaking down.  This video shows what it ended up looking like.  More than just dope.   

I also thought I would show how the current measurement compares with two other meters. 

https://youtu.be/EkQ6CCj7jmU
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
The following users thanked this post: SeanB, Jon.C

Offline MacMeter

  • Frequent Contributor
  • **
  • Posts: 319
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1913 on: September 16, 2017, 09:28:58 pm »
AMAZING, originally a $20 meter, guessing after time, parts, and labor, now CUSTOMIZED at over $500!
 

Offline Cliff Matthews

  • Supporter
  • ****
  • Posts: 1833
  • Country: ca
    • General Repair and Support
Re: Handheld meter electrical robustness testing.
« Reply #1914 on: September 16, 2017, 09:46:09 pm »
AMAZING, originally a $20 meter, guessing after time, parts, and labor, now CUSTOMIZED at over $500!
The exercise is not to waist time and money (maybe it's pastime with a purpose?). Joe's channel is the only one I know of that stands up to poor DMM manufacturers by sharing what could have been done but wasn't (for a whole host of reasons).
 

Offline MacMeter

  • Frequent Contributor
  • **
  • Posts: 319
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1915 on: September 16, 2017, 10:05:53 pm »
AMAZING, originally a $20 meter, guessing after time, parts, and labor, now CUSTOMIZED at over $500!
The exercise is not to waist time and money (maybe it's pastime with a purpose?). Joe's channel is the only one I know of that stands up to poor DMM manufacturers by sharing what could have been done but wasn't (for a whole host of reasons).

You misinterpreted my post, I love the time and effort Joe takes to produce his videos, not sure where he finds the time. My point was there are probably some that would love one of these tiny meters that are customized to such a higher quality degree, but it would cost TOO MUCH in reality. So again, a $20 meter can be "upgraded" to much better grade, but I'm sure Joe would laugh at being able to make any money after his time, labor, and parts, even at $500!
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1916 on: September 17, 2017, 03:05:13 am »
AMAZING, originally a $20 meter, guessing after time, parts, and labor, now CUSTOMIZED at over $500!
The exercise is not to waist time and money (maybe it's pastime with a purpose?). Joe's channel is the only one I know of that stands up to poor DMM manufacturers by sharing what could have been done but wasn't (for a whole host of reasons).

You misinterpreted my post, I love the time and effort Joe takes to produce his videos, not sure where he finds the time. My point was there are probably some that would love one of these tiny meters that are customized to such a higher quality degree, but it would cost TOO MUCH in reality. So again, a $20 meter can be "upgraded" to much better grade, but I'm sure Joe would laugh at being able to make any money after his time, labor, and parts, even at $500!

If you would like a better handheld meter the best option is to just buy one that meets your needs.   If you are interested in seeing a particular product  improved, I would contact the manufacture and let them know what features you are interested in.  I would never suggest anyone attempt to modify their handheld meter like I have shown.  I certainly would never offer any sort of a modified handheld meter or kit for sale.  I would see this as nothing more than a scam.  Worse, you are putting people at risk over a few dollars.  Sorry, not interested.

I did hook up the programmer and downloaded the contents of the PROM for the ZT102.  I went ahead and opened the window for the Amps range so the uA no longer beeps.  I also moved down the warning and over range limits.  I started to look at the switch and it does not seem like there is a clean way to change it. 

This is the unmodified contents:
:10000000FFFFFFFFFFFFFFFFFF5200BE0070C903AD
:100010001017381844026E50644B3C3C0AFF40FFF6
:10002000C798E38264009600008000803B7E826F68
:100030004E020930010A9AF60984F509E8030A001C
:1000400000010001000798006400640064000000E3
:1000500000800080008000800080008000800080A0
:10006000817E00830100922A000000000000000051
:1000700053810080C57DE07C180100000000000075
:100080000000000000001013000E00070012030122
:100090000000000000001115000F0009000004021C
:1000A00000000000000000000000000A0000000046
:1000B00000000000000000000000000B0000000035
:1000C0000D0002100D00032020000320200003106B
:1000D0000080008000800080410003050D000220A8
:1000E0000080008000800080008000800080008010
:1000F0000080FFFFFFFFFFFF5AC7CC0F0FA20000D9
:00000001FF


 
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1917 on: September 17, 2017, 05:37:57 pm »
What ever happened with Randomtronics?   I was watching his review of the AN8002 and I am not so sure the RMS conversion is as bad as it was made out to be in the video so I though I would run a quick test of my own to compare the ZT102 with a few meters. 



Randomtronic's video may be found here:
https://youtu.be/oNss6h0Zu98

How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline MacMeter

  • Frequent Contributor
  • **
  • Posts: 319
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1918 on: September 17, 2017, 06:54:26 pm »
Joe, did you read the first few comments on the YouTube page? There were some that pointed out his little mistake that he then acknowledged. All a bit over my newbie head.
 

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1919 on: September 17, 2017, 07:14:01 pm »
Yes, I read them.  I thought I would try and make it a little clearer. 


Rob C1 month ago

I am still confused by the comments is this meter true RMS or not??

Reply•   
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
The following users thanked this post: MacMeter

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 6869
  • Country: us
Re: Handheld meter electrical robustness testing.
« Reply #1920 on: September 18, 2017, 12:53:40 am »
Someone asked about how these changes to the ZT102 effected its frequency response. 

https://youtu.be/0nxjyqJf2jI?t=2
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline sleemanj

  • Super Contributor
  • ***
  • Posts: 2601
  • Country: nz
  • Professional tightwad.
    • The electronics hobby components I sell.
Re: Handheld meter electrical robustness testing.
« Reply #1921 on: September 18, 2017, 02:18:02 am »
What ever happened with Randomtronics? 

I think he must have moved or something and his equipment is still in packing boxes going by recent replies to comments.
~~~
EEVBlog Members - get yourself 10% discount off all my electronic components for sale just use the Buy Direct links and use Coupon Code "eevblog" during checkout.  Shipping from New Zealand, international orders welcome :-)
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 3849
  • Country: ca
Re: Handheld meter electrical robustness testing.
« Reply #1922 on: September 18, 2017, 03:23:41 am »
True-RMS (calculation) is AC coupled in the DMM IC used in the AN8002, AN8008 etc.
I thought any DC offset is ignored as part of the calculation.

But some DMM's include the DC portion if using the good old analog AD536 true-RMS converter (which costs much more than a cheap multimeter...)
Joeqsmith, didn't you already try adding a DC offset to a waveform, many posts prior?

 

Offline Fungus

  • Super Contributor
  • ***
  • Posts: 11405
  • Country: 00
Re: Handheld meter electrical robustness testing.
« Reply #1923 on: September 18, 2017, 11:08:55 am »
True-RMS (calculation) is AC coupled in the DMM IC used in the AN8002, AN8008 etc.
I thought any DC offset is ignored as part of the calculation.

But some DMM's include the DC portion...

I'd argue that it's more correct to include the DC portion because not all waves are symmetrical.

Where there's a DC offset it might be better to have a vpp function but I don't recall seeing that on a meter.
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 3849
  • Country: ca
Re: Handheld meter electrical robustness testing.
« Reply #1924 on: September 18, 2017, 05:30:10 pm »
I have a DMM with a switch for true-RMS AC+DC, or true-RMS AC only. Basically switches in/out a coupling cap to the true-RMS converter IC.

On the grid, pretty much no DC offset due to transformers. Missing DC is OK there, but not doing measurements on SMPS DC bus etc.

The DMM IC has result registers for DC and AC true-RMS (LPF) so they could be both used but the econo MCU is very basic and can't do math like multiply, square-root etc.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf