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Topic: weird button on bench top digital multimeter (very old) (Read 9692 times) previous topic - next topic

weird button on bench top digital multimeter (very old)

Hi guy's

I have some old (very old) KONTRON DMM 3002 bench top digital multimeter and I like the old bugger as it works very fast and is pretty precise .. but, there is a button on the thing that I have no clue what it does, nor I managed to figure it out doing trial and error procedure. I opened and immediately closed the device as it is not something I want to thinker with (looks like it has AD converter made out of discrete parts)

So if you look at the pic, the button in question is the pressed one, or if not clear which one is pressed, the one with "--" sign.

Anyone have any ideas?

Re: weird button on bench top digital multimeter (very old)

Reply #1
btw, if anyone has idea what to "test it with" (the unknown button), lemme know :D .. I kinda feel stupid I use the bugger for a while and never knew what the -- button is for

When I switch the dmm to the -- the display count from 0000 up approx 1 per sec, the output on the hi-lo is 5 or 10 or 12V depending on the white buttons, and it is constant (scope show less then +-10mV 50Hz hum)

I tried attaching 100nF - nothing changed (still counting, still same speed), tried diode too, nothing happened .. so maybe it is a counter :D .. donno what would that be useful for but ..

Re: weird button on bench top digital multimeter (very old)

Reply #2
I guess it's not used at all. On the other model "DMM 3003" it's for capasitance.
I can't post links (as this is my first post), but searching for "DMM 3003" comes up with images where that button is for microfarad.

Re: weird button on bench top digital multimeter (very old)

Reply #3
I guess it does nothing at all. They probably had one casing and put different models inside like namochan suggested.

btw. the first thing that came to my mind was an episode of Friends in which Monica was trying to figure out what a switch on the wall did ;-) ( http://www.youtube.com/watch?v=EFiPR5Gg9g4 )

Re: weird button on bench top digital multimeter (very old)

Reply #4
I guess it turns on the output as a DC generator for fixed voltages. The symbol used correspond to DC values, vs ~ for AC.

Re: weird button on bench top digital multimeter (very old)

Reply #5
my guess of the button would be for factory calibration.

the counter at approximately 1s to check for internal clock timing.

output of 5v, 10v or 12v are for voltage accuracy check.

Re: weird button on bench top digital multimeter (very old)

Reply #6
Why not but why add an external button for that ?

Re: weird button on bench top digital multimeter (very old)

Reply #7
I'd say namochan is correct and that it is meant to be used for capacitance .. the 3003 version I believe proves that.

Re: weird button on bench top digital multimeter (very old)

Reply #8
it is a dream button, when you push it it free your mind so you can dream of the best function it suppose to do ! and it count secs for you :-)

Sec counter might be useful for, break/dream timing,  time your new design run without smoke,  time for charging by old cap  etc  :oP

Re: weird button on bench top digital multimeter (very old)

Reply #9
I'm pretty sure it's not-connected option as explained, but why not feed it a 5V P-P 1KHz signal and see if it's a frequency counter?

Re: weird button on bench top digital multimeter (very old)

Reply #10
tried both 3V3 and 5V 100Hz to 10KHz ... no changes :(

when I opened the device from the bottom side other buttons have additional small boards on them and this one was only connected to the motherboard so looks like it miss that small board to be 3003 version

I do not need any additional options voltmeter and ampermeter work perfectly .. measuring resistance also works ok but I do not use it for that ... nor I'd use capacitance meter even if it was there .. it was just "I had to know what the button is for" and looks like -- means "not working" :D

Re: weird button on bench top digital multimeter (very old)

Reply #11
it is obviously for measuring the inverse logarithmic of brown-matter particles per nanometer, output in dBT

or a help key.

Re: weird button on bench top digital multimeter (very old)

Reply #12
multiple sites due to it's speed and configurability.

Re: weird button on bench top digital multimeter (very old)

Reply #13
Does someone have service manual for the kontron dmm 3002