One last thing to add to the thread. The parts had drifted about 12%. In addition, the older instruments have 100ohm source impedance. In order to measure these we need an instrument with 30ohm source impedance. I can't explain why this is the case but the higher source impedance did not give accurate values. On Wed, Jul 18, 2018 at 7:59 AM Guy Ramsey <[log in to unmask]> wrote: > I got pulled into a Receiving Inspection problem. Our test instrument, an > old HP 4192A impedance meter, and a newer Instek 6020 tell us that our X5R > capacitors are out of spec. > A 100uF, 10%, 6.3V capacitor measures between 25% and 30% below the > nominal value. The instruments have Kelvin probes and are zero calibrated > at frequrency, 120Hz the test waveform is 500mV rms. > Does anyone have any advise? >