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# Best way to accurately measure capacitance w/ osciloscope?

I am sure there are many ways to measure capacitance w/ an oscilloscope, and one of the annoying things is that some capacitors have different capacitance at different voltages and test frequencies. My original idea was to use the RC time constant and a known resistor, but I think this is probably the least accurate way to do this. Would using a sine wave function generator and figuring out capacitive reactance (and capacitance) be the better method? OR what about measuring resonant frequency of a LC tank circuit? Or some other method I have not mentioned? What's the best?

## Discussions

3 years ago

You could use the cap in an astable 555 timer cct and use the scope to measure the frequency produced. The value can then be calculated from the formula for the 555 timer astable cct.

http://www.eleccircuit.com/simple-capacitance-meas...