Hi,
Has anyone used the QA462 to measure high value electrolytic capacitors?
I have tried but there seems to be an artifact at certain frequencies e.g. 10kHz where the Capacitance produces a huge spike.
This appears to be an issue with an LCR meter as well, as around certain frequencies there is an error reading while above and below this frequency there appears to read correctly.
Any advice is welcome as I’m baffled by this one…
Phil
OK, I think I got it, its because Xs gets very low at high frequencies which messes up the calculation.
Hi @HorriblyPearshaped, can you share the main screen with left and right channels? Usually, if you have an artifact in the impedance screen, you’ll be able to see what is causing the disturbance by looking at voltage (left channel) or current (right channel).
I think you figured this out based on your comment, but it’s an elusive point for sure. The wiki link below has some more info on how to optimize. But note in the “Test a Cap” section you’ll see the currents can rise at higher frequencies. Depending on your settings, the QA462 output might have run out of range to report the current (in that case, use a lower sense resistor) OR the QA403 input might have overloaded???
Hi @matt, thanks for the feedback, large electrolytics hit self resonance in the audio region or close to it. This is what’s happening here, this is why it occurs on my LCR meter also…so that’s why there are spikes as the impedance drops and negative values are seen in Capacitance as it turns Inductive…Phil
