Products > Test Equipment
FLUKE 107 - absolute garbage lasted 2 years
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TomKatt:

--- Quote from: christian.burger on June 30, 2024, 02:58:50 pm ---Yes, there was battery leakage and I've reconstructed the terminals. It's working fine other than the readings which are off, but also I don't think that is related to the problem, unless you know something specific about that.

--- End quote ---
I lost track, but it seems like this is the first mention of battery leakage?  I’m not a big believer in coincidence - there has to be a connection.
shapirus:

--- Quote from: christian.burger on June 30, 2024, 02:58:50 pm ---Yes, there was battery leakage and I've reconstructed the terminals. It's working fine other than the readings which are off, but also I don't think that is related to the problem, unless you know something specific about that.
--- End quote ---
Check this one out:

floobydust:

--- Quote from: joeqsmith on June 30, 2024, 05:20:45 am ---
--- Quote from: floobydust on June 30, 2024, 04:20:56 am ---These small Flukes, they deleted the usual protection zener-connected transistors.
So I don't expect them to be robust in certain situations. Not the same protection despite the familiar parts such as surge resistor, PTC, MOV's.
TVS D1 is across the battery so the BAV199 CR1 might dump overvoltages there - still a terrible idea.

--- End quote ---

My Fluke 107 survived five positive and negative 14kV 100us full width half height transients through a 2 ohm source.  Very few meters I have looked at would survive that level.  While the 107 was eventually damaged at 15kV, I was able to repair it and it is still fully functional today.   Sadly I can't say that about many of the meters I have looked at and they get recycled. 

It's not even a question of cost.  I have a Fluke 101 that has yet to be damaged with all my testing and it cost less than $50.  Consider I ran a Keysight U1282A that was closer to $800 which couldn't survive the same levels as my cheap Amprobe AM510.   And with all the custom parts, it could not be repaired.   



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No, it's the Ohms source protection that I'm questioning. I don't see the clamp semi's on the board pics. That has to handle significant current until the PTC heats up, which takes several seconds for long surges.
Did you apply transients (either polarity) to the multimeter on Ohms? I can't remember if your transient generator can output either polarity, you don't give out info about it.

ESD testing I've done is 10 hits with both polarities. A BBQ lighter is only one. It's possible to protect against one polarity but not the other.
factory:

--- Quote from: TomKatt on June 30, 2024, 03:14:05 pm ---
--- Quote from: christian.burger on June 30, 2024, 02:58:50 pm ---Yes, there was battery leakage and I've reconstructed the terminals. It's working fine other than the readings which are off, but also I don't think that is related to the problem, unless you know something specific about that.

--- End quote ---
I lost track, but it seems like this is the first mention of battery leakage?  I’m not a big believer in coincidence - there has to be a connection.

--- End quote ---

There was no mention before, but there was mention of the batteries being replaced, but not why.
From experience battery leakage can make a right mess and cause leave conductive mess behind & corrode away fine traces.
Was it caused by Duraleak by any chance?

For example there is a thermometer at work that had batteries leak, it works fine at lab temperatures of 20°C, take it anywhere else it measures way, way out of spec. It's been out for calibration several times to the crappy external company work uses now, they pass it every time, hopefully someone has junked it by now as it's unusable.

David
joeqsmith:

--- Quote from: floobydust on June 30, 2024, 04:01:31 pm ---
--- Quote from: joeqsmith on June 30, 2024, 05:20:45 am ---
--- Quote from: floobydust on June 30, 2024, 04:20:56 am ---These small Flukes, they deleted the usual protection zener-connected transistors.
So I don't expect them to be robust in certain situations. Not the same protection despite the familiar parts such as surge resistor, PTC, MOV's.
TVS D1 is across the battery so the BAV199 CR1 might dump overvoltages there - still a terrible idea.

--- End quote ---

My Fluke 107 survived five positive and negative 14kV 100us full width half height transients through a 2 ohm source.  Very few meters I have looked at would survive that level.  While the 107 was eventually damaged at 15kV, I was able to repair it and it is still fully functional today.   Sadly I can't say that about many of the meters I have looked at and they get recycled. 

It's not even a question of cost.  I have a Fluke 101 that has yet to be damaged with all my testing and it cost less than $50.  Consider I ran a Keysight U1282A that was closer to $800 which couldn't survive the same levels as my cheap Amprobe AM510.   And with all the custom parts, it could not be repaired.   



--- End quote ---

No, it's the Ohms source protection that I'm questioning. I don't see the clamp semi's on the board pics. That has to handle significant current until the PTC heats up, which takes several seconds for long surges.
Did you apply transients (either polarity) to the multimeter on Ohms? I can't remember if your transient generator can output either polarity, you don't give out info about it.

ESD testing I've done is 10 hits with both polarities. A BBQ lighter is only one. It's possible to protect against one polarity but not the other.

--- End quote ---

Sorry you lost me.  I have gone over the waveforms many times over the years and where they came from.     

When I wrote "... survived five positive and negative 14kV 100us ..." it would be understood that was both polarities.  As always, I subject the meter to 5 transients of each polarity.  I do this for every function the meter has except those involving current.  This is the way I have always conducted these tests.   For the 107, that electrically has 5 functions, that is 5 transients X 2 polarities X 5 functions, or 50 transients.   I run that for each voltage level.    For the 107, there were a minimum of 10 levels, so a bit over 500 transients.

 As far as your comment: "... I don't see the clamp semi's on the board...", they are certainly present in the photos you linked.  I would assume your inability to identify them is just a lack of education on your part.   No big deal.   It doesn't help that many expert reviewers will point to PTC and call them MOVs or point to diodes and call them resistors.  For a non educated viewer, it just adds confusion.    As far as how the clamps actually work, I have gone over that a few times.   

The resistance and other low voltage modes are protected with the high speed clamps which are downstream from the PTC and surge rated resistors.  This is what was damaged on my 107 when I applied the 15kV transient.   I went over the repairs. 

The 107 is a very electrically robust meter.   Calling it absolute garbage after the OP leaves the batteries in for an extended time says more about the owner than the product. 
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