Using a Multimeter to Determine the Quality of a Capacitor

A capacitor is a device that holds a charge. In the purchase, many people will judge the quality of capacitors through the multimeter. Do you know how to use a multimeter to judge the quality of a capacitor?

Depending on the capacity of the electrolytic capacitor, the Rx10, Rx100, and Rx1K gears of the multimeter are usually selected for testing. The red and black pens are connected to the negative electrode of the capacitor (before each test, the capacitor needs to be discharged), and the quality of the capacitor is judged by the yaw of the hands.

1. If the hands quickly swing right and then slowly retreat to the left, the capacitor is generally good.

2. If the hands are no longer swiveled after they have been swung, the capacitors have been broken down.

3, if the hands gradually swing back to a certain position after the stop, indicating that the capacitor has been leakage.

4, if the hands do not swing, indicating that the capacitor electrolyte has dried and pushed to lose capacity.

Some leaky capacitors are not easy to judge accurately with the above method. When the voltage value of the capacitor is greater than the battery voltage value of the multimeter, according to the characteristics of the leakage current when the electrolytic capacitor is charged forward and the leakage current during reverse charging is large, the R×10K block can be used to reverse charge the capacitor. Whether the stylus stays stable (ie, whether the reverse leakage current is constant), the quality of the capacitor is judged and the accuracy is high.

The black pen is connected to the negative pole of the capacitor, the red pen is connected to the positive pole of the capacitor, and the hands quickly swing up and then gradually retreat to a point where they can't move, indicating that the capacitor is good. All the hands in a certain position stay unstable or stay and gradually The capacitor that has moved slowly to the right has been leaked and cannot be used anymore. The hands generally stay and stabilize within the 50-200K scale.