Hi, I need to test some potentiometer since I can't replace them. They are mounted in some difficult position. I must be sure they are working. usually I use dmm or amm. Recently I saw this octopus tester to use with one oscilloscope. For the potentiometer is this tester better than dmm or amm method?

 

I assume that DMM & AMM stand for Digital and Analogue Multimeters. I still like using them for stuff like this and really, extra equipment on my bench just creates clutter. Just my 2 cents worth though.

 

For verifying the functionality of a potentiometer I favour an analogue multimeter as you can flip the pot from end to end and watch the pointer. Digital meters are great when precise measurements are needed, analogue for checking functionality in general

 

The octopus tester with an oscilloscope can provide a more comprehensive testing method for potentiometers compared to a DMM or an AMM, as it can show the potentiometer's response to varying frequencies and waveforms. GTA Portal Login

Yes, but you only need that info infrequently for a new application, not if you are replacing the pot with the same device,..

A multimeter should be sufficient to verify that the pot is functional.

 

maybe I'm paranoid but I fear that when I move the potentiometer I could quickly "jump" a part where the reading is missing and the multimeter does not have time to detect this thing. However I try to move very slowly.
However, let's try to convey the intent of the original question. I can go to work by bike or by car. both are excellent. Does it take me less time if I go with the Ferrari?
I can use dmm or amm to test potentimeter. Both are great. if I use octopus tester, will I have more accurate results?


PS.
My potentiometers are used for position sensing.

 

I could quickly "jump" a part where the reading is missing

If that's your concern than just connect the oscilloscope to the pot wiper while also reading the voltage with the multimeter.
That will show any problems with the pot wiper contact.
You don't need the "Octopus Tester".

 

My potentiometers are used for position sensing.

For this, I'd recommend using a protractor to mark out degrees on a circular piece of cardboard glued centrally under the potentiometer knob and arrange for a pointer to be close to the outer edge of the cardboard circle. Rotate the pot through a sequence of angles and note the corresponding resistance. Move the pot both clockwise and anticlockwise to check for hysteresis. The bigger diameter the cardboard circle the better the accuracy of measurement. In this case, use a DMM, not an AMM. Depending on your application, if you are using a processor you can have a look-up table to correct for any offset and/or non-linearity

 

Hi, I need to test some potentiometer since I can't replace them. They are mounted in some difficult position. I must be sure they are working. usually I use dmm or amm. Recently I saw this octopus tester to use with one oscilloscope. For the potentiometer is this tester better than dmm or amm method?

When you say that you can't replace them do to where they are mounted, does that also mean that you are having to test them in-circuit? Or are you able to disconnect the leads so that you are only interacting with the mounted pot?

 

However, let's try to convey the intent of the original question. I can go to work by bike or by car. both are excellent. Does it take me less time if I go with the Ferrari?

No absolute answer is possible. The bike might be much faster in some situations, such as NY City traffic. There's a caretaker's house at a small hydro plant near here where the caretaker can bike across a foot bridge and get from town to home in a few minutes, but to drive requires a sixty mile trip.

As with so many things, the devil is in the details.

 

The way you need to test them will depend on what you are testing them for. Do you want to:
Check for broken tracks? use a low current analog or digital continuity tester.
Check for correct value and linearity? Use a good quality digital ohm meter.
Check for mechanical noise and drop-outs? The octopus would work for this.

 

Check for broken tracks?

I only must be sure there's no broken tracks.

When you say that you can't replace them do to where they are mounted, does that also mean that you are having to test them in-circuit? Or are you able to disconnect the leads so that you are only interacting with the mounted pot?

I can remove them but once I mounted them I must be sure they are in good conditions.


since all the potentiometer are the same may i make some sort of "tester" with arduino to read data from potentiometer and to compare them with good one data. maybe in excel . I have windows data fllow and plx-dax ecc.

 

If that's your concern than just connect the oscilloscope to the pot wiper while also reading the voltage with the multimeter.
That will show any problems with the pot wiper contact.

This afternoon I connected the potentiometer in series between the probe and the 1.2v square wave source. While i was looking at the screen i moved the potentiometer and i saw no noise in the wave all the time. What I didn't expect was that the amplitude never changed. The potentiometer is 2K.

 

That would be normal when wired in series because of the high impedance of the scope.
Connect the signal source across the pot and monitor the signal from the center tap to either side

 

what's the difference?

 

To see the amplitude change.
If the amplitude doesn't go from zero to the maximum signal voltage then the pot is defective.

 

ok lets try to put the number together. Today I made like this, 4-1-2-6-5-7. Please the me how you think to do that.

 

And connect the ground clip on 5 to 3.

 

ok thank you.
Today i will try.
PS.
nobody make me compliment for the Photoshop