What frequency should I use to measure capacitors properly?
What is the
purpose of the test? Acceptance/rejection test, binning components, correct circuit operation...?
Extreme example of why purpose is important...
Back in ~1980 phone calls were sent between telephone exchanges using 2
Mb/s PCM over twisted pair cables. The cable was spec'ed and measured at 1.6
kHz, and that was absolutely fixed and could not be varied. Why? Because even if the manufacturers didn't change the cable, changing the test would have allowed them to raise the price - and the GPO didn't want that!