Precautions for testing capacitors with a digital multimeter
1. Some multimeters have polarity markings on the capacitor socket. When measuring the most rigid electrolytic capacitor, the polarity of the measured capacitor should be consistent with the polarity of the capacitor socket.
2. The new digital multimeter (such as DT890B type) is equipped with a protective circuit for the capacitor block, so when measuring electrolytic capacitors with polarity, there is no need to consider the polarity of the capacitor,
3. Before measurement, the two electrodes of the measured capacitor must be short circuited and discharged, and then inserted into the measuring socket for testing to avoid damaging the instrument.
4. When measuring large capacity capacitors, it takes several seconds for the reading to stabilize. The capacitance value of the measured capacitor should be read after the number displayed on the LCD screen stabilizes.
5. The early production of digital multimeters required manual zeroing of their capacitor settings. Before measurement, the "ZEROADJ" knob should be adjusted first to display a value of zero and eliminate zero point errors. Zero point adjustment is required every time the capacitor is switched.
6. The new digital multimeters (such as DT890B, DT930F+, DT940C, DT970, DT980, DT1000, etc.) all use capacitive impedance method to measure capacitance and achieve automatic zeroing. When using this type of instrument, there is no need to consider the zero point error of the capacitive gear. When the conversion switch is set to the capacitor mode, even if the reading does not return to zero, the instrument can quickly return to zero as long as the capacitor is plugged in.
