1, first look at the appearance, the appearance of the film capacitor is likely to have problems.
2, with a multimeter resistance gear test film electric two feet should be very high resistance, if there is a capacitance meter, measure the capacitance value with the shell on the mark in line.
3, room temperature test performance, including capacity, loss, insulation resistance, withstand voltage, ESR and so on. Especially need capacitors which aspects of the performance of the focus on which to test.
4, do simulated life test. Normal temperature and normal test performance is no problem, but also to see whether the life can last.
5, choose a reputable manufacturer of capacitors.
6, if the use of the requirements are not high can be bought from the market some general purpose, do a copy of their own test, passed, you can rest assured that the use of.
7, film capacitors are metal foil as the electrode, and its and polyethylene, polypropylene, polystyrene or polycarbonate and other plastic films from the ends of the overlap after winding into a cylindrical structure of the capacitor. And according to the type of plastic film and were called polyethylene capacitors, polypropylene capacitors, polystyrene capacitors and polycarbonate capacitors.