Capacitance meter is one instrument that you should have in your toolbox if you are an electronics hobbyist, or if you’re a professional electronic technician. If you can’t afford to buy such instrument or you you can’t find it on your local store then here is the good news: you can build your own capacitance meter. You can build a capacitance meter adapter to interface? between the capacitor to be measured and your general purpose voltmeter to read the capacitance value. Here is the schematic diagram of the circuit:
Just install a connector in place of voltmeter symbol, and now you can plug your analog or digital voltmeter to read the capacitance. If you use a digital one, then make sure if your digital voltmeter averages the signal reading with long time constant (over 1/10 second). Many low-cost digital voltmeter (DVM) usually is a dual slope integrator type that do the job. If your DVM is a fast sampling type then you should insert an RC filter, a 1k resistor and a 10uF electrolytic capacitor should be sufficient. More information about this circuit design can be found at [Source: http://www.hqew.net/circuit-diagram/Capacitance-Meter-Circuit_3380.html ]
