Handheld meter robustness testing

[Hydrawerk]

I wonder why the Fluke 87V failed at tests when exposed to a 1500V pulse. Isn't it UL listed? Was there already a faulty MOV or PTC?

There seems to be good protection on the PCB of Fluke 87V. I am not sure if Fluke 101 is better designed.
https://www.eevblog.com/forum/testgear/fluke-101-multimeter-teardown/

[joeqsmith]

I wonder why the Fluke 87V failed at tests when exposed to a 1500V pulse. Isn't it UL listed? Was there already a faulty MOV or PTC?
..
There seems to be good protection on the PCB of Fluke 87V. I am not sure if Fluke 101 is better designed.

Does a meter (any meter) need to be functional in order to pass the IEC standards?  Good protection from a safety perspective or good protection from an ability to survive a transient?

I am not sure what it would take to damage the 101.   The 107 failed at a level about 10X higher than the 87V.   There was another member who ran the 101 on a purchased generator to repeat my tests and indeed it survived.  I was not too surprised as I had added another 1KV and doubled the FWHH of the pulse beyond what the standard called for.   If by better designed, you mean the 101's ability to survive a transient  over the 87V, I don't think there is any question.   

[joeqsmith]

It's been a while I posted about any new meters and longer since anything was good enough to put on the home made generator.   

A few people had asked me about running one low cost meter in particular.  One member offered to send one.  So I have gone ahead and purchased it.  I also picked up a another UNI-T UT61E.  Maybe adding some MOVs will help it at least make it to the surge test.    If it's anything like the UT181A, it will need more than MOVs to get it to survive.

[joeqsmith]

No updates to the spreadsheet this time.   Just having some fun.

[joeqsmith]

I have been curious about the GS version of the UT61E since I first read about it.  I was unable to find a distributor that would sell one and ended up getting another standard UT61E.  There have been several posts where people have recommend adding MOVs to the 61E.   

Both 5kY's UT61E and D  failed the grill starter ESD test.  My goal with this next video is to have a look at what effect the MOVs would have on the ESD test and see if I can improve the robustness of this new 61E.

So stay tuned....


 

[MosherIV]

Hi Joeqsmith

I need to put an order in to Farnell (here in the UK) for fuses for my Fluke187. I can get 4 of these
http://uk.farnell.com/epcos/b72210s0381k101/varistor-40-0j-385vac/dp/1004398

(they are the same as the ones I bought but just from different side of Farnell, I think you call them Element14 in US)
for you to install in the UT61E if you like?

pm my an address I can send them to.

[rsjsouza]

I have been curious about the GS version of the UT61E since I first read about it.

GS version?

[MosherIV]

GS version ?

GS certified. This version is sold in the European markets. As mentiined it has beefed up input protection compared to the Chinese version.

[joeqsmith]

Anyone interested in a slightly used UT61E?  Appears to have little wear. Includes some spare parts, original box and manual.

A little pre warning.  There will be two parts.  The first video runs about an hour.  I spent a fair amount of time explaining the  what/whys and ran several tests to prove out my results.   Like any problem, there are going to be many solutions.  I touched on only a few. 
   
It's not a good video for the person who just wants some circuit they can copy but I do show everything that is going on including the mods. 

So if you're one of these people who have added MOVs or GDTs to your UT61E or if you have told people this is a smart thing to do, these videos are just for you.   

[PedroDaGr8]

Anyone interested in a slightly used UT61E?  Appears to have little wear. Includes some spare parts, original box and manual.

A little pre warning.  There will be two parts.  The first video runs about an hour.  I spent a fair amount of time explaining the  what/whys and ran several tests to prove out my results.   Like any problem, there are going to be many solutions.  I touched on only a few. 
   
It's not a good video for the person who just wants some circuit they can copy but I do show everything that is going on including the mods. 

So if you're one of these people who have added MOVs or GDTs to your UT61E or if you have told people this is a smart thing to do, these videos are just for you.

Can't wait to see the videos!

[joeqsmith]

Enjoy.

[3db]

Hi Joe
Thanks for the video.
Great work, appreciate the effort you put into this. 

[joeqsmith]

Hi Joe
Thanks for the video.
Great work, appreciate the effort you put into this. 

Glad you enjoyed it.  Here is the conclusion.

[whitevamp]

thank's for the vids.
keep up the great vids.

[SeanB]

Thanks for the video, a good upgrade for the meter, and very good as well.

[Lightages]

Yes, good work Joe. I am glad that you put in those disclaimers about this making any difference for safety. All the modifications surely made a difference in the survival of the meter but people really still need to understand that this does not make the meter any more suitable for high energy power work. Thanks for the time and money you put into the videos.

[joeqsmith]

Yes, good work Joe. I am glad that you put in those disclaimers about this making any difference for safety. All the modifications surely made a difference in the survival of the meter but people really still need to understand that this does not make the meter any more suitable for high energy power work. Thanks for the time and money you put into the videos.

I have never made any claims about safety, only robustness.   I watched several videos on the UT61E before I made these last two.   This included yours. 

https://youtu.be/hhBbvIf3E0s?t=84

I didn't understand most of your comments about it somehow relating to the IEC standards.  The UT513 is an insulation tester and supplies a DC voltage.    My guess is had spark gaps been installed the meter would not have survived.  I am not even sure if you had MOVs in it like the GS meter that it would make it. 

What I don't like about your video is that it leaves people with the idea that the meters can survive 5KV.  If you measured the voltage across the meter when you ran the test, my guess is you had no where near the 5KV claimed.  If you look at the manual for the UT513, the short circuit current is less than 2mA.  The PTC would not even flinch at this.  Novices watching that video may think, hey 5KV, let me hook my Brymen to a 5KV 10KW supply.

[MosherIV]

Thanks Joeqsmith 

Guess just fiting the MOVs does not do much 

Always enjoy your videos

[joeqsmith]

Thanks Joeqsmith 

Guess just fiting the MOVs does not do much 

Always enjoy your videos

Glad you enjoyed them. Isn't it better to know why I was concerned.

[Lightages]

Yes, good work Joe. I am glad that you put in those disclaimers about this making any difference for safety. All the modifications surely made a difference in the survival of the meter but people really still need to understand that this does not make the meter any more suitable for high energy power work. Thanks for the time and money you put into the videos.

I have never made any claims about safety, only robustness.   I watched several videos on the UT61E before I made these last two.   This included yours. 

https://youtu.be/hhBbvIf3E0s?t=84

I didn't understand most of your comments about it somehow relating to the IEC standards.  The UT513 is an insulation tester and supplies a DC voltage.    My guess is had spark gaps been installed the meter would not have survived.  I am not even sure if you had MOVs in it like the GS meter that it would make it. 

What I don't like about your video is that it leaves people with the idea that the meters can survive 5KV.  If you measured the voltage across the meter when you ran the test, my guess is you had no where near the 5KV claimed.  If you look at the manual for the UT513, the short circuit current is less than 2mA.  The PTC would not even flinch at this.  Novices watching that video may think, hey 5KV, let me hook my Brymen to a 5KV 10KW supply.

Again we seem to talk past each other. I am agreeing with you, agreeing with your assertions, and never accused you of making any claims to safety. I acknowledge what you say and agree.

My video was never meant to show anything other than the meter did not survive a simple insulation tester voltage. If you ever take the time to read what I have said about meter safety you will know where I stand. My video was a simple experiment and talked about one thing. I never said that a meter that could survive a 5kV test voltage was a safe meter. A meter that is rated at 600V CATIV that can't withstand 5kV at low energy could imply that it does not meet that rating. That was my point and intent.

Your work is appreciated.

[joeqsmith]

The UNI-T UT90A was one of the first meters I purchased to benchmark.   It's been damaged and repaired so many times I call it the cat (because it has nine lives).   So here's for all you UT90A fans.

[3db]

Van Halen Eruption !!   
 

[joeqsmith]

Van Halen Eruption !!   
 

I couldn't toss out a meter that could do this! 

With the UT61E now passing some basic transients I thought it needed a backlight to go with all that added protection.   So here's my twist on adding backlight to the UT61E.     

[joeqsmith]

Van Halen Eruption !!   
 

I could toss out that could do this! 

Wow, even I have a rough time decoding that.     

I couldn't toss out a meter that could do this! 

Anyway..... the first meter I ever owned was I think made by Heathkit. It used vacuum tubes and was given to be.   The first new meter my parents bought for me for my birthday.  It was a Micronta capable of reading 50,000 ohm with what they called a range doubler.    I used the meter all of my high school years and repaired / made lots of little projects with it.   I then got my first Fluke (in my 20's)  and it's been digital ever since. 

Today I am going back in time and playing with the first analog meter I have owned since those early years.  This is pretty much the bottom of the barrel for meters but I am finding some things I actually like about it even over my Brymen!      

So stay tuned.....

[Fungus]

How much extra do you think it would cost Uni-T to build the new super meter?

(compared to the existing one)