2 Ways for Testing a Capacitor with Digital Multimeter and Voltmeter

Electronics circuits use capacitors to store voltage. Every electrical and electronics circuit needs a capacitor. Troubleshooting an electronic circuit may involve testing a capacitor. There are multiple ways to test a capacitor like digital multimeter, voltage meter, and ohmmeter.

Before testing a capacitor, make sure to disconnect the capacitor from the circuit. And short the terminals of the capacitor using a resistor of at least 1k. Try to avoid contact with the terminals during the process. Otherwise, the charge on the capacitor may cause you an electric shock.

Testing a Capacitor with a Multimeter

Testing a capacitor with a multimeter is the easiest and quickest way. The required instrument of the test is a digital multimeter with a capacitance testing feature.

  • Remove the capacitor from the circuit and short the terminal to avoid and electric shocks.
  • Set the digital multimeter to capacitance setting.
  • Connect the probes of the multimeter to the capacitor terminals.
  • For the polarized capacitor, connect red prob to positive and black to negative terminal of the capacitor.
  • For nonpolarized, you can connect it in either way.
  • Now, look at the screen of the digital multimeter to read the capacitance of the capacitor.
  • You can compare the reading with the rating printed on the capacitor. If they are close, the capacitor is good.
  • In case of large variation, the capacitor may be considered a bad capacitor.
  • A bad capacitor can be replaced with a new similar rating capacitor.
Testing a capacitor with digital multimeter and voltmeter

Testing a Capacitor with Voltmeter

Testing a capacitor with a voltmeter can give you an idea if the capacitor is good or bad. For this method, you need a voltmeter and a power supply. The voltage of the power supply must be less than that of the capacitor.

  • Disconnect the capacitor from the circuit and discharge.
  • Connect the capacitor to the power supply and charge it for at least 4 to 6 seconds.
  • Make sure the voltage of the power supply is less than the printed voltage on the capacitor.
  • Now disconnect the capacitor from the power supply.
  • Do not touch or short the capacitor terminals.
  • Connect the capacitor to the voltmeter.
  • Read the voltmeter reading if it close to the power supply voltage or not.
  • If it is close to the supply voltage the capacitor is good.
  • If the reading much less the capacitor is bad.

Conclusion

  • Always disconnect the capacitor from the circuit to test it.
  • A digital multimeter may give you the exact capacitance of the capacitor.
  • Testing a capacitor with a voltmeter may tell you if it good or bad capacitor.

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