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ICL7107 Voltmeter calibration


Hi, I need some advice regarding the attached schematic. I built the schematic, it is working but I don't know how to calibrate it. I need to measure between 0 V and 50 V.
I set the Rx1= 100R and Rx2a= 100k, but if I rotate R4, then the displayed value modifies.
Do I need to calibrate it using a standard voltmeter ?



Well-Known Member
Most Helpful Member
Your options are as follows. Calibrate the 200 mV range and let the resistors to their thing. e.g 1%, 0.1% etc,

or calibrate near the nominal voltage you need to measure accurately. e.g. inject 25V and calibrate to 25V.

A calibration source is usually better than your meter. It might be a 2.500 V source.


The calibration should be as follows.
1. Set the values for Rx1 and Rx2a
2. Set the displayed value by rotating R4 ?

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