Handheld meter robustness testing

[joeqsmith]

The 87V on the chopping blocks.  Interesting, they only look at the AC voltage mode and they do not appear to functional test the meter between steps.  How do they know where it fails?

[Fungus]

The 87V on the chopping blocks.  Interesting, they only look at the AC voltage mode and they do not appear to functional test the meter between steps.  How do they know where it fails?

You can clearly see it jump in the air at 2:02 

[joeqsmith]

A jumping meter is the criteria for pass/fail. 

[zaoka]

Joe did you ever seen Iwatsu multimeters?

Like  Hioki these are top class stuff... 

[joeqsmith]

I think I used one of their scopes many years ago but I have never seen any of their handhelds.   

The one in this link does not look too bad:
https://www.eevblog.com/forum/testgear/iwatsu-voac22-dmm-teardown/

Yokogawa is the OEM manufacturer for Iwatsu

Do you own one? If so, do you like if?

[zaoka]

These are made under different names:

Yokogawa TY720
Kyoritsy KEW1062
...

Iwatsu makes bench meters, I seen older model and never owned it. That latest model is really fancy https://www.iti.iwatsu.co.jp/en/products/voac/voac7602_top_e.html

[rsjsouza]

Joe, these are interesting clips. The fact they don't functionally test the meter after each "shock" is most probably related to the nature of these tests: they are supposed to contain and withstand arc flashes instead of "surviving".

I suspect the power strip in fumes is most probably due to the varistors.

I do prefer the results of your tests, as they measure the amount of headache a DMM can give you (as I only work with average power circuits).

[joeqsmith]

Joe, these are interesting clips. The fact they don't functionally test the meter after each "shock" is most probably related to the nature of these tests: they are supposed to contain and withstand arc flashes instead of "surviving".

I suspect the power strip in fumes is most probably due to the varistors.

I do prefer the results of your tests, as they measure the amount of headache a DMM can give you (as I only work with average power circuits).

The opening statement was:
"It's important that test instruments and other electrical test tools are independently evaluated to make sure they can survive high voltage transients"

At 9:29
"With stout input protection our test instruments are built to survive"  then they go on to show you some big boy toys. 

Now I'm not suggesting that you need to actually test the instrument to know that it survived the test....  Of wait, that's exactly what I am suggesting!  Of all the meters they sell, the one that failed at the lowest level during my tests is shown to be a superstar.    

Of course, I wouldn't claim a meter passed ESD without ever testing it with the leads.

[Vgkid]

That was a great video update. You fooled me at first...

[joeqsmith]

I finished testing the Woods DMMW3.  I should have the video and spreadsheet uploaded tomorrow. 

Had some fun with the old 101 and 107 while I was at it. 

[gnavigator1007]

Any chance you'd do a video on the Aneng AN8002 cheapie? I just keep thinking about seeing the little fella in the box, since somebody posted about the AN8001 a few months back. I say the 8002 just for the temp measurement

[joeqsmith]

Any chance you'd do a video on the Aneng AN8002 cheapie? I just keep thinking about seeing the little fella in the box, since somebody posted about the AN8001 a few months back. I say the 8002 just for the temp measurement

 

Ok, here's the deal.  I was out of coffee and needed to order some.  A few people had asked about this meter and I ended up with a KASUNTEST ZT102 and the KT6666 along with my coffee.    The ZT102 looks very close to the one you are asking about.  There are a few videos on YT for it.  If you want to see these stressed to failure, stay tuned...

In the meantime.

[gnavigator1007]

Really got to wonder how many names they're selling these under.

[joeqsmith]

The Woods DMMW3 pocket multimeter




The ZT102 will be next..

[MacMeter]

IMPRESSIVE video, as always! I happen to know how much time it takes to make videos. Getting all that testing done, and uploading in a day, is crazy fast. Then you actually repair the meter, geez, wish I had the knowledge and skills. You really LIT the CANDLE, several times.

Looks like a better meter for pocket use then my old Radio Shack "clamshell" meters. I would never test current with it anyways, but for quick voltage and continuity tests would seem handy for $30. Also, I don't have anything that small that can read Hz.

Thanks once again for taking all that time and effort to educate us with these tests. Don't know of anyone else willing to fry meters like you do!

Look forward to the ZT102 video.

[Vgkid]

It would be neat to see how it fares with more space/creapage distance.
Looking forward to the zt102.

[joeqsmith]

IMPRESSIVE video, as always! I happen to know how much time it takes to make videos. Getting all that testing done, and uploading in a day, is crazy fast. Then you actually repair the meter, geez, wish I had the knowledge and skills. You really LIT the CANDLE, several times.

Looks like a better meter for pocket use then my old Radio Shack "clamshell" meters. I would never test current with it anyways, but for quick voltage and continuity tests would seem handy for $30. Also, I don't have anything that small that can read Hz.

Thanks once again for taking all that time and effort to educate us with these tests. Don't know of anyone else willing to fry meters like you do!

Look forward to the ZT102 video.

Thanks. 

Yes, it's a fair amount of time to run a meter.  The manual ranging meters are the worse!  Or meters that have a lot of features and just refuse to die.      

I knew when I saw the first pictures that this meter was not going to do well.  It's just too tight.   Normally there is little I can do to repair a meter.  Most of the time I will damage some hard to get part making them recycle bin filler material.   

Personally, I will take function over form.   The smallest meter that I actually like is that 101.  That thing is just so robust.   People were complaining about it not having a current input and I always felt that was a plus.   It prevents non experienced electrical people from making at least one mistake.  And if you blow it up, you know there is a good story behind it! 

[joeqsmith]

It would be neat to see how it fares with more space/creapage distance.
Looking forward to the zt102.

I had looked at some inexpensive pocket meters before and I took a calibrated dremel tool to is to improve the brakedown.   This put more an more stress on other parts until it failed.

I don't think there is much I could do to improve the robustness of that meter because of the lack of space.  IMO, I would have left out that 200mA circuit and tried to make the meter more robust using that space.

I watched a few reviews of the ZT102.  The reviewers all seemed to like it.   

[Vgkid]

I was thinking about the low current range. For the most part, I very rarely actually measure current below .5 Amps. Especially when it comes to home wireing, I don't do it.

[kwass]

The Woods DMMW3 pocket multimeter

Thank you for that in-depth testing!!!
The DMMW3 did better than I thought it would in your torture test.  It's not a Fluke but I still like it.

[joeqsmith]

The Woods DMMW3 pocket multimeter

Thank you for that in-depth testing!!!
The DMMW3 did better than I thought it would in your torture test.  It's not a Fluke but I still like it.

If we only consider the meters ran after I changed my test setup, it's pretty bottom of the barrel. Attached, the top graph is roughly the number of meters that failed each test. The lower graph shows how many meters survived after each test. 

Many people mention the Fluke 87V is the gold standard.  I believe that as well.  Notice that large peak in the top graph and the sharp roll off in the lower?  Once we get beyond that we are starting to see the better meters stand out.  Products that are more robust than the 87V are to the right of that hump.   

Dave's rebranded Brymen 235, the Fluke 115, the 101, the 107 and even that HIOKI I looked at are really in a whole different class when it comes to their front end robustness.   This is where I am expecting Dave's 121GW to fall in.

Some meters will place the high speed clamps after the switch.  The Woods is not like that.  Once I damaged the meter the first time and repaired it,  I only tested the meter in its voltage mode.   You may believe the meter was just running all fine and dandy but we know the meter was damaged again right away.   It was the same circuit and with those clamps not being switch out, the  would fail just like before.

For me personally, $30 for the Woods or just under $50 for the 101 it's no contest. 

[rsjsouza]

The opening statement was:
"It's important that test instruments and other electrical test tools are independently evaluated to make sure they can survive high voltage transients"

Yes, you are right. I glossed over these statements.

At 9:29
"With stout input protection our test instruments are built to survive"  then they go on to show you some big boy toys. 

Now I'm not suggesting that you need to actually test the instrument to know that it survived the test....  Of wait, that's exactly what I am suggesting!  Of all the meters they sell, the one that failed at the lowest level during my tests is shown to be a superstar.    

Of course, I wouldn't claim a meter passed ESD without ever testing it with the leads.

Likewise. As I told you before, I prefer your tests as they give you a measure of the headache you will have with your equipment.

BTW, I just got a Fluke 27/FM and it is an incredible piece of gear that I suspect would survive a nuclear blast.

[Fungus]

BTW, I just got a Fluke 27/FM and it is an incredible piece of gear that I suspect would survive a nuclear blast.

 

[MacMeter]

My go to "SAFE" meter is the EEVBlog BM235, but just to have a little home meter, I just bought the KASUNTEST ZT102, Amazon Prime, delivered for $20. I saw it on EBay for $16, but waiting 2-3 weeks from China with return hassles, made it silly to go that route. As you all know these are rebranded under other names. The EBay site was however informative, in that there are 3 models, one is a 2000 count, not many features, another one has NO temp option, in that switch position is just a 2nd "off" setting. The 3rd one is actually the ZT102, as it shows the temp option on the dial.

If I'm lucky enough to find a replacement fuse, I hope it's not 50% of the cost of the meter. Almost disposable at this price.

[joeqsmith]

My go to "SAFE" meter is the EEVBlog BM235, but just to have a little home meter, I just bought the KASUNTEST ZT102, Amazon Prime, delivered for $20. I saw it on EBay for $16, but waiting 2-3 weeks from China with return hassles, made it silly to go that route. As you all know these are rebranded under other names. The EBay site was however informative, in that there are 3 models, one is a 2000 count, not many features, another one has NO temp option, in that switch position is just a 2nd "off" setting. The 3rd one is actually the ZT102, as it shows the temp option on the dial.

If I'm lucky enough to find a replacement fuse, I hope it's not 50% of the cost of the meter. Almost disposable at this price.

I have the KT6666 on order as well.  My plan is to run the 102 first.