Handheld meter robustness testing

[sambonator]

The meter did have what appeared to be a defective SIBA branded fuse that I replaced early on.   I don't feed the transients into the current inputs of the meter so no, the damage to the capacitance mode had nothing to do with my changing out that fuse.   That was a completely separate problem. 

Normally on the better class of meters, the high speed clamps will fail and save the down stream components.  On the low end meters, normally something else in front of the clamp (normally the PTC) will brake down and it's game over.   In this case, the entire front end checked out.  This may be a first.   It also tells me that the meter could use some improvements.   It has enough other problems that it's hardly worth spending more time on though. 

I sense that Kyoritsu/Yokogawa designed that meter to be built with low cost parts and low-cost labor (Thailand) to maximize profit.
AFAIK Hioki is the only Japanese brand that still make their meters in Japan with their own ICs.  Hioki LCDs seem to have the best readability from extreme vertical angles (from below and above).



.

[sambonator]

Here is another Japanese meter that may look interesting:

https://overseas.sanwa-meter.co.jp/items/detail.php?id=13

It has nano siemens at least but the contrast seems a little dim from the catalog and pictures.

[Edit]

Not a newer model for sure.... it has been reviewed and digits are more slim but not too dimmed . Capacitance reading is quite fast

I can't get past the Sanwa PC7000 aesthetics... but what is interesting is the 500,000 count DCV mode, and its low cost ($270 shipped from Japan). 
I think its manufactured in China.

[2N3055]

I think that one is based on Brymen BM867. It even uses same pc cable
.

[tautech]

Spotted in another thread:
A poor little Brymen being asked to check the EHT voltage in a Tek CRO. 



Only a couple of times its rated voltage. 
Recommended, NO. Impressive YES !

[sambonator]

I think that one is based on Brymen BM867. It even uses same pc cable
.

Hey you're right, layout is nearly identical, except Sanwa PC7000 has a temperature setting on the rotary.
So, call is a BM867+?     Oh now that I think about it, I seem to recall seeing reviews of different Sanwa meters, where the box said "Made in Taiwan."  Maybe Brymen makes meters for them?

[joeqsmith]

Spotted in another thread:
A poor little Brymen being asked to check the EHT voltage in a Tek CRO. 


Only a couple of times its rated voltage. 
Recommended, NO. Impressive YES !

     I continue to abuse the little pocket Brymen that member True posted about.  After everything I have done to this meter, it would be fun to take Dave's SANWA and have my own shoot out.   A badly abused Brymen vs a brand new Sanwa.      

[joeqsmith]

I sense that Kyoritsu/Yokogawa designed that meter to be built with low cost parts and low-cost labor (Thailand) to maximize profit.
AFAIK Hioki is the only Japanese brand that still make their meters in Japan with their own ICs.  Hioki LCDs seem to have the best readability from extreme vertical angles (from below and above).

I doubt there is much labor in these meters once the the line is setup.  They may have just wanted a design they could maintain.   Akira Tsukamoto would need to chime in.

Personally, the display that for me has been the most memorable is the UNI-T UT181A.  That color just pops.  The worst display I have seen was by far my old Fluke 97 scope meter. 

[sambonator]

I sense that Kyoritsu/Yokogawa designed that meter to be built with low cost parts and low-cost labor (Thailand) to maximize profit.
AFAIK Hioki is the only Japanese brand that still make their meters in Japan with their own ICs.  Hioki LCDs seem to have the best readability from extreme vertical angles (from below and above).

I doubt there is much labor in these meters once the the line is setup.  They may have just wanted a design they could maintain.   Akira Tsukamoto would need to chime in.

Personally, the display that for me has been the most memorable is the UNI-T UT181A.  That color just pops.  The worst display I have seen was by far my old Fluke 97 scope meter.

The newer meters with TFT or OLED displays look phenomenal compared to the standard LCD... I also like what Aneng did with their Q1, with reverse backlit LCD.  I know Dave doesn't like it but I sure do.

[joeqsmith]

The newer meters with TFT or OLED displays look phenomenal compared to the standard LCD... I also like what Aneng did with their Q1, with reverse backlit LCD.  I know Dave doesn't like it but I sure do.

I watched that video and thought that he was concerned with the short battery life with having to drive the back light.  Function over form, which I tend to agree with.  I would need to go back and watch it again. 

With the stories of short life, unable to view in outside light, I doubt I would ever own an OLED meter.  The 181A does look nice but has a pretty short battery life.  Of course, it uses a non-standard battery and you can't use the meter while it charges.  To me this would be a problem if it were my only meter.  At some point, the battery will fail and I will need to sort out a replacement.  Maybe print a new cover for it using AAs.   That sounds safe.        It is a nice looking meter.  The components they used look good.  Layout is lacking.   Not real impressed with their choice of materials.  LCD is easy to scratch etc...   Could be a really nice meter, but you know, I say that about every meter!!   

 

[Fungus]

The newer meters with TFT or OLED displays look phenomenal compared to the standard LCD... I also like what Aneng did with their Q1, with reverse backlit LCD.  I know Dave doesn't like it but I sure do.

You must hate batteries.

[malagas_on_fire]

Hi

here is a follow up the comment on the video on the timing between videos where the measuring  + settle time were improved for 150pF capacitor by using a chronograpth. Starting point begins when placing leads on terminals and stop when value is stable


 I exagerated the counting on the first video of the yokogama by stop the chronograph only when you spoke which was 11.44s.
Now these are the new counting stoping right on the stable value and there might be aditional error of course.

- Original : 9.66s
- Improved: 8.69s




Chronograpth is decimal memory capable.

[Edit] : Sorry wrong / duplicated image

[joeqsmith]

I have explained to you that I have not changed the meter's design and the repairs I made would not effect the settling time.  A picture of a stop watch doesn't provide any backup of your claim.   As I said, if you wanted to prove there was a change, you would need to line up the two videos and compare them.   Your claim of 1.5x times (7.81s vs 11.44s) should tell you that you are doing something wrong. 

So rather than spend more time trying to explain it to you, here are the two videos sync'ed.   

https://www.youtube.com/watch?v=FNU_G77rRQ0&feature=youtu.be

[malagas_on_fire]

Thanks a lot for the syncing ,no need to explain more  ... i perceived wrongly "have" from "haven't" on the Yokogawa update video and kept the wrong idea all the way over  and over,

[sambonator]

The newer meters with TFT or OLED displays look phenomenal compared to the standard LCD... I also like what Aneng did with their Q1, with reverse backlit LCD.  I know Dave doesn't like it but I sure do.

You must hate batteries.

To the contrary, I love batteries... I keep buying them... many of them... frequently.... 

Is that you Fungus loving my old battery?


 

[malagas_on_fire]

If that's the expire date then expect the worse   They all may leak... at least its written on the back of the casing. The OLED in the Q1 doesn't seem quite good compared to an 8008, doesn't mean that other OLED based meters are worse for example the Agilent / Keysight U1253A looks very nice... but remember power hungry display

https://youtu.be/Zele19jm1MQ?t=673

[joeqsmith]

Thanks a lot for the syncing ,no need to explain more  ... i perceived wrongly "have" from "haven't" on the Yokogawa update video and kept the wrong idea all the way over  and over,

You may have indeed misunderstood and had the wrong ideas but I have no clue where you came up with that 1.5X factor or what you were showing with that stop watch.   It was pretty obvious the settling times were not effected as I had explained. 

[malagas_on_fire]

Thanks a lot for the syncing ,no need to explain more  ... i perceived wrongly "have" from "haven't" on the Yokogawa update video and kept the wrong idea all the way over  and over,

You may have indeed misunderstood and had the wrong ideas but I have no clue where you came up with that 1.5X factor or what you were showing with that stop watch.   It was pretty obvious the settling times were not effected as I had explained.

Since i got confused i may crystallized the idea and tried  between the two videos find the difference. The start point is the same but stop is wrong because stopped when you started talked about the values and that made the difference. Yeah insisted in the wrong ideia....  blinding the obvious...   

[joeqsmith]

Since i got confused i may crystallized the idea and tried  between the two videos find the difference. The start point is the same but stop is wrong because stopped when you started talked about the values and that made the difference. Yeah insisted in the wrong ideia....  blinding the obvious...   

Blinded by the obvious 

When I watch some of my videos, I will catch myself at times making the same error over and over.  Some of these can be pretty funny.  It's odd that after the fact, the brain has no problem picking it out.  I have also constructed things wrong, over and over.  Some could be very simple.  Its strange. 

[rsjsouza]

If that's the expire date then expect the worse   They all may leak... at least its written on the back of the casing. The OLED in the Q1 doesn't seem quite good compared to an 8008, doesn't mean that other OLED based meters are worse for example the Agilent / Keysight U1253A looks very nice... but remember power hungry display

Malagas, just keep in mind the Q1 is not OLED but instead a reverse plain LCD.
Also, the U1253A/B are more prone to OLED self-destruction than the newer U1273A - at least there are only one or two reports on the latter model about OLED durability, while the former has tens of reports.
(disclaimer: I have a U1273A and it is already five years old since mfg date - its OLED is still in pristine condition).

[malagas_on_fire]

Oppss it's even worse??? I thought it was an OLED LCD  5 years is a young meter as long as you don't expose much heat, it will last more years. Currently working with two U1251 A /B models at work and one (A) of them has the plastic of the rotary switch ripped off ( maybe too exposure to sunlight). They work fine , are super simple to use accurate in the sense it doesn't requre much calibration over the years.

One thing i've noticed at home during some experiments with electronics using AC 230V with isolation transformer, the meters BM235 e UT139A measuring V / A ( vice-versa) of the circuit.  would display OL when mangled the contacts from old plugs. it does create arcs and maybe AC transients in lower energy (about 6VA ) and trigger the OL situation on the meter. It doesn't matter if i swap the meters for A and other for V . To disable the OL of course it is required to turn off. the units.
 I didn't repeat the experience to avoid any potential damage to meter or DUT or even me and used better plugs.

is this some sort of protection implemented on the meters?

[rsjsouza]

Oppss it's even worse??? I thought it was an OLED LCD  5 years is a young meter as long as you don't expose much heat, it will last more years. Currently working with two U1251 A /B models at work and one (A) of them has the plastic of the rotary switch ripped off ( maybe too exposure to sunlight).

Sunlight and heat destroy anything. Last summer I was fixing my pool equipment and my trusty Fluke 27/FM was under the sunlight for about 15min or so. It was facing down when I was not using it, so the LCD wouldn't become dark but, even still, its display became faded. It only came back to normal when I reseated and cleaned the zebra strips.

One thing i've noticed at home during some experiments with electronics using AC 230V with isolation transformer, the meters BM235 e UT139A measuring V / A ( vice-versa) of the circuit.  would display OL when mangled the contacts from old plugs. it does create arcs and maybe AC transients in lower energy (about 6VA ) and trigger the OL situation on the meter. It doesn't matter if i swap the meters for A and other for V . To disable the OL of course it is required to turn off. the units.
 I didn't repeat the experience to avoid any potential damage to meter or DUT or even me and used better plugs.

is this some sort of protection implemented on the meters?

I suspect the arcs may be shooting the voltage to very high levels. That or the meters are susceptible to high frequency transients.

Some meters, even from reputable manufacturers such as HPAK, showed this behaviour. The major issue is that there are usually several tradeoffs when designing the input section of a multimeter: safety level, noise/sensitivity, bandwidth...

This is only solved by a very good and well tested design.

[2N3055]

I have a Brymen BT-75 voltage tester. It works great. It will auto switch on when you connect tips for continuity test. It will actually auto switch on when you probe few hundred kiloohms.
It has dark case. I left it in the sun last summer. The PTC based low Z circuit in front end heated enough for it to start leaking enough to switch on tester just laying there in the sun.. Still works normally but kept switching on by itself..  So back in the toolbox it went..
Sun is strong here...

[malagas_on_fire]

Oppss it's even worse??? I thought it was an OLED LCD  5 years is a young meter as long as you don't expose much heat, it will last more years. Currently working with two U1251 A /B models at work and one (A) of them has the plastic of the rotary switch ripped off ( maybe too exposure to sunlight).

Sunlight and heat destroy anything. Last summer I was fixing my pool equipment and my trusty Fluke 27/FM was under the sunlight for about 15min or so. It was facing down when I was not using it, so the LCD wouldn't become dark but, even still, its display became faded. It only came back to normal when I reseated and cleaned the zebra strips.

One thing i've noticed at home during some experiments with electronics using AC 230V with isolation transformer, the meters BM235 e UT139A measuring V / A ( vice-versa) of the circuit.  would display OL when mangled the contacts from old plugs. it does create arcs and maybe AC transients in lower energy (about 6VA ) and trigger the OL situation on the meter. It doesn't matter if i swap the meters for A and other for V . To disable the OL of course it is required to turn off. the units.
 I didn't repeat the experience to avoid any potential damage to meter or DUT or even me and used better plugs.

is this some sort of protection implemented on the meters?

I suspect the arcs may be shooting the voltage to very high levels. That or the meters are susceptible to high frequency transients.

Some meters, even from reputable manufacturers such as HPAK, showed this behaviour. The major issue is that there are usually several tradeoffs when designing the input section of a multimeter: safety level, noise/sensitivity, bandwidth...

This is only solved by a very good and well tested design.

Thanks for the information.  Don't have test gear to measure the voltage spike in a controlled manner .. if any-- so the best way was to prevent using decent plug connectors which is convinent in AC mains for the sake of the meters, circuits, triacs. and human I believe that BM235 was sensitive to the MSD system that joeqsmith use to shield the Gossen Metrawatt Metrahit. ( Sorry edit: to test he automotive Multimeter AIOESON??? EM135)

https://youtu.be/q_89qoFMivg?list=PLZSS2ajxhiQBvWvqMVLdRQMjGofKpQUJr&t=3458

[joeqsmith]

I have a Brymen BT-75 voltage tester. It works great. It will auto switch on when you connect tips for continuity test. It will actually auto switch on when you probe few hundred kiloohms.
It has dark case. I left it in the sun last summer. The PTC based low Z circuit in front end heated enough for it to start leaking enough to switch on tester just laying there in the sun.. Still works normally but kept switching on by itself..  So back in the toolbox it went..
Sun is strong here...

Odd as the PTCs resistance will increase with temperature.   Perhaps something else is happening.

[joeqsmith]

I mentioned I had two other videos in the works.  One is some long term testing I have been doing on the Brymen pocket meter that member True had claimed to have so many fail.   I would say its at least another month out.   

In the past, I have had to test some of my designs for vibration.  These were typically larger/heavier than a handheld meter and I would suggest a more harsh environment than a typical meter would ever see.   I am thinking I may try to come up with some sort of simple test jig to run a few meters on and may start with this little pocket meter.    I suspect mostly they see the drop or maybe low frequency low displacement.  I have not found any standards yet that companies have followed.   

Watching a few videos on the subject.  This one is pretty decent.