[REQ] - Oscilloscope Calibration Procedure
« on: June 22, 2004, 04:15:43 PM »
Hi there !

I cleaned my Schlumberger 5222 (old 2 ways oscilloscope) a few days ago and while cleaning the knobs, I just changed the whole calibration of the device (the Y axis calibration has changed, not the X axis (I haven't cleaned the time base knobs right now ;) ).

Does anyone have the maintenance manual of this device ? Or a similar device ?
Or maybe a general procedure for oscilloscope calibration (any brand) ?



[REQ] - Oscilloscope Calibration Procedure
« Reply #1 on: June 22, 2004, 05:17:36 PM »
there should be a 1 volt peak to peak calibration pin somewhere, hook your probe onto that, 1:1 , and dial in the correct height of the trace.
thats about the only calibration you need to do.
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[REQ] - Oscilloscope Calibration Procedure
« Reply #2 on: June 23, 2004, 02:28:04 AM »
Yes, I've got this little test signal on my 'scope. I use it it to adjust my probes and a few things on my 'scope.

The biggest problem comes from the input inverter. On the channel A of my 'scope, I can invert the signal (turn it of 180°).

Inverting the signal on this channel will turn the signal (quiet normal ;) ) but will also introduce a small offset (not normal ;) ).

I think this error can be caused by a calibration problem or maybe a capacitor is dead in the circuitry of the inverter.


[REQ] - Oscilloscope Calibration Procedure
« Reply #3 on: June 23, 2004, 03:00:39 AM »
That will depend on if the test signal you get from the scope is symmetric around zero. Most aren't.

Try switching the scope to AC, and see if it's still offsetting when inverting.

Jakob E.
..note to self: don't let Harman run your company..

[REQ] - Oscilloscope Calibration Procedure
« Reply #4 on: June 23, 2004, 03:09:45 AM »
Yep, the test signal is 1V p-p and is centered.

When testing on the normal input (AC), I center the test signal, ... everything is clear.

But when I invert the signal using the inverter switch, the test signal is still 1V p-p but a mall offset (something like 0.5V) is introduced, so the signal is no longer centered ...

Do you think that this problem is due to calibration error or a maybe a component has burned in the circuitry of the 'scope ?

Thanks for your answers.


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