measuringcapacitance

Measuring Capacitance

Various ways to measure capacitance

There are many ways to measure capacitance. Some of them are:

• Measure the resonant frequency of a tuned circuit having a known inductance and mathematically derive the capacitance value. Put the unknown capacitance in parallel
• with a known inductance. Connect your signal generator to this via a small (2 to 5 pf)
• capacitor. Use an oscilloscope or RF detector to measure RF across the LC pair while
• tuning the signal generator for an RF voltage peak. Once you know the LC resonance
• frequency you can calculate the C-value from frequency and the known inductance.
• Measure the impedance of a capacitor at a known frequency and mathematically derive the capacitance value.
• Measure the time constant of an RC oscillator using a known value for R, and mathematically calculate the capacitance value.
• Using a small micro-controller, like maybe an Arduino, set an interrupt trigger on one port Turn on the pull-up resistor on that port. Then toggle the other port with the DUT capacitor connected across both ports. You can use the micro-controller timing function to measure charge and discharge time and from that calculate the capacitance value.