Products > Test Equipment
FLUKE 107 - absolute garbage lasted 2 years
stj:
if this meter had alkaline battery failure then the pcb needs a vinegar-wash.
alkaline batteries dont leak liquid, it's a vapor and it gets into and under stuff.
floobydust:
I use vinegar to neutralize the salts, with a toothbrush scrub. Then a water rinse, then repeat but with IPA and let it dry overnight or in an oven.
Some parts of the circuit board are very sensitive to leakage currents. Hard part is the rotary switch lube, washing that off leads to a new problem for the switch.
--- Quote from: joeqsmith on June 30, 2024, 04:28:23 pm ---
--- 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.
--- End quote ---
I agree the OP could be too angry about the warranty or self-inflicted leaking battery damage. Some forums forbid titles containing judgements or slander/smearing and we might need that here.
So your tests find the 107 electrically robust and not OP's problem.
The MOV's only bring the transient voltage down to 910-1,500V (hard clamp 25A). It's still too high for the silicon, so clamp zener-connected transistors or TVS are usually used for the second level protection. "high speed clamps" well there's a single BAV199 clamping to what? Compare with the 17B schematic. It's hard to speculate without a 107 schematic but eyeballs show no clamp transistors as well as missing MOV #3. TVS D1 implies they're dumping transients to the power rails and assuming the battery helps - which is new and further economy. That's why I'm saying they could have made a mistake, have to be very careful.
OP, you can't calibrate out a hardware problem. 30% out is too much, fix the hardware first and remember to hate Duracell and love your Fluke lol.
Gyro:
Please post a clear photo of the PCB (preferably both sides) so that we can see the extent of any contamination / corrosion.
coppercone2:
--- Quote from: stj on June 30, 2024, 04:51:28 pm ---if this meter had alkaline battery failure then the pcb needs a vinegar-wash.
alkaline batteries dont leak liquid, it's a vapor and it gets into and under stuff.
--- End quote ---
its not a vapor, its a aerosol. The only vapor they make is water. What they can do is spritz a mist that settles on various parts, and leak liquid that wicks up surfaces, and wicks up wires (like a sponge).
If it evaporates into a vapor, its water that leaves the electrolyte caustic chemicals behind as a solid.
The battery consists of various inorganic chemicals, water and some specialty additives (surfactant, etc)
If the battery were to leak out, and then peacefully dry up in a puddle on the bottom of the battery cavity, you would only have humidity damage in the meter. But usually it starts misting (hissing, high pressure) and it makes corrosive fog.
vapor is actually evaporated stuff in molecular gas form. A lead acid battery WILL make some small amount of corrosive VAPOR because it has sulfuric acid in there (a chemical that does not vaporize easily, but it will in fact make corrosive acid gas if it does). Thankfully sulfuric acid does not like to vaporize and it takes a really hot malfunctioning battery to start essentially boiling H2SO4 aqueous into H2SO4 vapor.
If you ever come across a alkaline battery leak, it often sounds like a capacitor pop, followed by intermittent hissing or farting noises after that.
factory:
I guess the next question is, were the old batteries that were removed, supplied by Fluke with the meter or not?
David
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version