How to use a multimeter to judge the quality of a capacitor - News - Global IC Trade Starts Here Free Join

SMD Aluminum Electrolytic Capacitor

Photocoupler

Testing small capacitors is quite straightforward. To check a capacitor, you can use a multimeter set to the resistance range (usually the "kΩ" setting). Connect the red and black probes to the two terminals of the capacitor. If the needle swings quickly from left to right—by one or two units—it indicates that the capacitor is in good condition. The larger the swing, the better the capacitance.

If the needle doesn't move at all, it means the capacitor is likely open-circuited or damaged. On the other hand, if the needle moves but doesn’t return to its original position (or stays at a low resistance value), this suggests that the capacitor has a leakage or has been broken down. In such cases, the capacitor should be replaced immediately to avoid any potential issues in the circuit.

It's also important to discharge the capacitor before testing, especially if it's a large one, to prevent damage to the multimeter or personal injury. Always ensure the capacitor is fully discharged by shorting its terminals with a resistor or using a dedicated capacitor discharger.