How to measure electrolytic capacitance? -Teach you how to measure quickly with a multimeter
Judging whether the capacitor has breakdown, leakage, capacity reduction or disappearance usually requires the capacitor to be detected in the open circuit state.
1. Take the capacitor out of the circuit board with tools such as electric soldering iron, and clean the pins.
2. Observe the appearance inspection. If there is bulge, liquid leakage and broken pin, the capacitor has been damaged.
3. Determine the polarity of the pin. The slightly longer pin of the new capacitor is the positive electrode and the short pin is the negative electrode. In addition,
one end marked with white is negative and the other end is positive.
4. The capacitor is discharged before measurement and connected to the capacitor pin with a small resistor.
5. Adjust the multimeter to R*1K gear and zero it.
6. Measure the negative electrode of the capacitor with a red stylus and the positive electrode with a black stylus, and observe the change of the pointer.
7. Under normal circumstances, the pointer should swing to the right (this is the charging process), and then slowly swing to the left to return to infinity.
8. A zero pointer indicates capacitance and penetration, and a small amplitude of image swing indicates leakage of the capacitance. If the pointer does not swing,
it indicates that the electrolyte of the capacitance is dry and has no capacity.
When the withstand voltage value of the capacitor is greater than the voltage value of the battery in the table, according to the characteristics of small leakage
current of electrolytic capacitor in forward charging and large leakage current in reverse charging, R*10K can be used for capacitor reverse charging measurement.
The black stylus is connected to the negative electrode and the red stylus is connected to the positive electrode. Observe whether the reverse current is constant.
If the pointer swings back to a clear position (50~200KΩ) after the capacitor is charged, then it slowly swings to the right, indicating that the capacitor has leaked electricity.
