How to measure capacitance of a capacitive sensor?
The way a multimeter calculates the capacitance of a capacitor is by using an integrator operational amplifier.



However, in real terms, it is:



But if you really don't want to use any measurements, it would be best if you look at the product specifications. Any difference between the calculated and actual capacitance is very small, if it's in good condition.

The circuit of an integrator op amp is as follows below.







simulate this circuit &ndash; Schematic created using CircuitLab