Capacitor value

[jack23]

Hello,

I used a RLC meter, also reffered to as a RLC digibridge, to measure the capacitance of capacitors. The meter can be adjusted to any frequency. When I set it to say 1KHz, and connect the wires to the capacitor leads, the meter shows a certain capacitance value for that capacitor. Then, when I set the frequency of the meter to say 100Hz, I get a different measured value for the same capacitor. The difference is not an extreme difference, but it is noticable when switching between frequencies.

My question is, why does the meter show me different values for the same capacitor when I switch between frequencies? Capacitance is equal to Q/V ( coulumbs/volts) and not dependant on frequency ( only when dealing with capacitive reactance we must account for the frequency ).

Thank you.

 

[kchriste]

In the ideal world, the readings would be exactly the same. In reality, your capacitor is made up of small amounts of resistance and inductance in addition to its rated capacitance. It is these "parasitic" components that result in the different readings at different frequencies.