- 1). Separate the test leads of the ESR meter so that the probes are not touching. Turn the meter on. If the meter has more than one mode, ensure that is set to ESR mode. The meter may perform an automatic calibration routine when powered on. If so, wait until it indicates it is ready to use. This may be indicated by an LED or an audible tone.
- 2). If the capacitor to be measured is in-circuit, ensure that the circuit is not energized. Unplug the electronic equipment the capacitor is installed in, if possible.
- 3). Discharge the capacitor before testing if the ESR meter does not do this automatically. Choose a high-wattage resistor with a resistance of between 5 and 50 times the rated voltage of the capacitor. Connect a test lead to each lead of the resistor. Carefully touch the other ends of the test leads to the leads of the capacitor and hold them there for a few seconds. Use a voltmeter to confirm that the capacitor is not charged. The voltmeter should show a value of zero.
- 4). Touch the ESR meter test probes to the leads of the capacitor. Read the ESR of the capacitor from the meter. It may be displayed as a deflection on an analog scale, a level on an LED bar scale or a digital readout. Some ESR meters also provide an audible tone indicating the range of the ESR.
- 5). Determine if the ESR is acceptable by comparing the measured ESR value with the guidelines provided with the meter.
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