How to judge the quality of capacitors
Common faults of capacitors are: open circuit, short circuit, leakage and capacitance reduction. For capacitors with large capacity, the pointer multimeter resistance block can be used to determine the quality of the capacitor and conduct qualitative analysis of its quality.
Multimeter gear selection principle: large capacity, small gear; Small capacity and large gear. Typical capacity greater than 47 μF select R´ 100 stops, capacity 1~47 μF selected R´ 1 K stop, capacity less than 1 μF select R´ 10 K gear.
First, short-connect the two pins of the capacitor (the purpose is to release the charge stored by the capacitor), and then connect the two pens of the multimeter to the two pins of the capacitor in parallel to observe the swing of the dial pointer: if the pointer deflects and quickly returns to the starting point, the capacitor is good; If the pointer does not move, the capacitor has an open circuit, and the capacitor leaks. If the pointer does not move at "0 Ω", a short circuit has been broken; If the pointer stops on a scale in the middle, the capacitor leaks.