Handheld meter robustness testing

[Fungus]

Also, I'm really surprised that Fluke 107 is a different size from the 101.  I figured they'd reuse the same chassis to save costs, but I guess not!  That's fluke for ya: they don't cut costs to please their accountants.

Adding amps measurement means it needs fuses inside.

And maybe bigger track gaps ... although that wouldn't make it much bigger.

[joeqsmith]

From the pictures I have seen of the 101 and 107, they don't look at all the same.   One look at the 101 and you can understand why it can survive the tests I have put it through.   

Again, this was a VERY good call on your part.   I doubt I would have bought this meter had you not recommended it.  I wonder if any of the new meters can survive this same amount of punishment.   

[Fungus]

From the pictures I have seen of the 101 and 107, they don't look at all the same.   One look at the 101 and you can understand why it can survive the tests I have put it through.

Yep. The 101 obviously has much more input protection. It will be interesting to see if the 107 survives as well as the 101.

Again, this was a VERY good call on your part.   I doubt I would have bought this meter had you not recommended it.

Aw, it was nuthin' 

[5ky]

I'm curious to see how the Amprobe holds up because Uni-T is the OEM of that specific model.  (take it apart along-side one of the Uni-T and you'll see a lot of similarities)  I assume Amprobe has them made to order so I'd imagine sufficient input protection is added.  We'll find out soon enough!

It was interesting to see that all of the CEM OEM ones (extech, circuit-test, southwire) all took damage.

How many are left completely unscathed now, seven or so?  They're dropping like flies 

[joeqsmith]

I think you will be very surprised by what has survived.  Of the eighteen I started with only five are unscathed.   Consider the new generator is running about 30% capacity,  I'm sure I can narrow it down. 

I am seeing a lot of what I call 87V damage where they are still usable.   My plan is to run these separately.     

[joeqsmith]

Second half of the 1.5KV tests.

[5ky]

Excellent!  I'm rooting for that radioshack one.  You can get it for $25 on ebay/amazon brand new.  If it weren't for its pathetic 100 uF max capacitance range, it would be a really good all around meter WITH true RMS.  I'm actually quite surprised it's gone this far.

I have a feeling that 107 will go the distance like your 101 did.   

 

[PedroDaGr8]

The unpopulated spots on the UT61E make me wonder how the European TUV tested version of the UT61E handles. It has those spots fully populated and has beefed up fuses if I remember correctly.

Sent from my LG-ls990 using Tapatalk

[Lightages]

joeqsmith:

I am rather impressed at the work and time you have put into these tests. Thank you very much for the time and effort, and cost! These tests certainly are weeding out meters that can't survive normal abuse, and not even abuse in some cases. Like I keep trying to tell people, the UT61E was capable of dying merely from walking around, and your tests kind of demonstrate that.

I am glad you like the BM869S so much and I hope it ends up at the end as one of the survivors.

5ky:

Thanks for throwing your money into the mix to get destroyed. This is a great service to all to learn what really is worth buying.

These tests certainly will demonstrate to people why they should consider spending money on good meters and not junk. From the tests so far, some meters will appear to be working right in some function but will be way off in other ways. This is a dangerous condition.

[joeqsmith]

Excellent!  I'm rooting for that radioshack one.  You can get it for $25 on ebay/amazon brand new.  If it weren't for its pathetic 100 uF max capacitance range, it would be a really good all around meter WITH true RMS.  I'm actually quite surprised it's gone this far.

I have a feeling that 107 will go the distance like your 101 did.   

 

If I were to pick from the meters you purchased in this group, it would be that one meter that you kept that I said I would not test even if you sent it.   

The unpopulated spots on the UT61E make me wonder how the European TUV tested version of the UT61E handles. It has those spots fully populated and has beefed up fuses if I remember correctly.

Really??!!

joeqsmith:

I am rather impressed at the work and time you have put into these tests. Thank you very much for the time and effort, and cost! These tests certainly are weeding out meters that can't survive normal abuse, and not even abuse in some cases. Like I keep trying to tell people, the UT61E was capable of dying merely from walking around, and your tests kind of demonstrate that.

I am glad you like the BM869S so much and I hope it ends up at the end as one of the survivors.

5ky:

Thanks for throwing your money into the mix to get destroyed. This is a great service to all to learn what really is worth buying.

These tests certainly will demonstrate to people why they should consider spending money on good meters and not junk. From the tests so far, some meters will appear to be working right in some function but will be way off in other ways. This is a dangerous condition.

I hope that the videos I made showing the generator and talking about the amount of energy I am using were helpful to you and others as well.   

It may have been interesting to have another UNI-T 139C in this mix as well just to see how it would do against the 61s.     

The only bad thing about putting the Brymen through all of these tests is it didn't have an 87V sitting there with it.   However, I do have a way to reproduce these tests now and have everything documented as to what I did.  So, nothing says that if an 87V happens to show up that it wouldn't get some special treatment.   

[Fungus]

I have a feeling that 107 will go the distance like your 101 did.   

The 101 appears to have more input protection:

https://www.eevblog.com/forum/testgear/fluke-101-multimeter-teardown/

https://www.eevblog.com/forum/testgear/review-first-impression-of-the-fluke-107-multimeter/

Most of the big components look identical but the 101 has an extra chain of seven resistors on the input. I can't see that in the 107.




I'm in the camp that damaged meter is a as-good-as-dead meter. If you know for a fact that some of the ranges are broken then how far can you trust the other ranges?

[Wytnucls]

That chain forms the 10MOhm impedance on the voltage range.
7x 1.433MOhm precision resistor. The 107 must have it too, probably on the other side of the PCB.
Protection is the same on both (1 fusible resistor, 1 PTC and 2 MOVs). 101 may have an advantage on wider trace separation.

[Fungus]

That chain forms the 10MOhm impedance on the voltage range.
7x 1.433MOhm precision resistor. The 107 must have it too, probably on the other side of the PCB.

Yep, I wondered if it has it them the other side of the PCB...can't find a photo though. Anybody have one they can open up and take a peek?

[5ky]

I'm in the camp that damaged meter is a as-good-as-dead meter. If you know for a fact that some of the ranges are broken then how far can you trust the other ranges?

I'm not following--did the 107 already take damage or something?

[Wytnucls]

That chain forms the 10MOhm impedance on the voltage range.
7x 1.433MOhm precision resistor. The 107 must have it too, probably on the other side of the PCB.

Yep, I wondered if it has it them the other side of the PCB...can't find a photo though. Anybody have one they can open up and take a peek?

[Fungus]

I'm in the camp that damaged meter is a as-good-as-dead meter. If you know for a fact that some of the ranges are broken then how far can you trust the other ranges?

I'm not following--did the 107 already take damage or something?

No...just talking in general about the half-dead ones.

[Fungus]

The 107 must have it too, probably on the other side of the PCB.

Yep, I wondered if it has it them the other side of the PCB...can't find a photo though.

...pic of 107

OK, so the 107 is going to survive as well! We'll have a joint winner!!

[5ky]

Yeah, I concur.  Injured is as good as dead.

That being said, is there a difference between keeping the user safe and dying in the process, versus keeping the user safe AND surviving the incident?  I feel like one is safety, and the other is safety AND robustness. 

[Lightages]

I would prefer that if a meter is going to fail, it fails completely and is obvious that it has failed. A situation where the meter still appears to work on some function but shows incorrect values on another or another range is just asking for someone to get hurt or for damage to occur. This is why it is always a good idea to have two reliable meters, and check them against each other regularly. If you are going to measure something potentially hazardous then you should always cross check before trusting the reading.

[joeqsmith]

Very few of the meters tested have failed 100% when they were damaged.   I am looking at seven of them now that have one or more features that still work correctly (but I doubt for much longer). 

[joeqsmith]

I stand corrected.  There are only three meters with partial damage... 

[tautech]

I stand corrected.  There are only three meters with partial damage... 

I'm very sure you will fix that. 
 

[joeqsmith]

I put together the next video showing the meters being ran at 2KV, 100us FWHH, 1us rise, 2 ohm source.   

https://www.youtube.com/watch?v=4gJ161tTBiI&feature=youtu.be


While the UNI-T UT90A was damaged during testing,  I pulled it apart and found my repaired trace was damaged but no other parts were taken out.  I repaired this area again.  Being it is the only meter that I has played Van Halen's Eruption, I figured I owed it one last life.   
     

[joeqsmith]

The 87V clones are tested at 2.5KV.   

[joeqsmith]

The remaining working meters are tested at 2.5KV 100us FWHH 1us rise 2 ohm source.   



The next video will show testing at 3 and 4KV.