A capacitor tester is a device used to measure the capacitance of a capacitor. Capacitors are electronic components that store electrical energy in an electric field. They are found in a variety of electronic devices, such as radios, TVs, computers, and cell phones.
Capacitor testers come in a variety of shapes and sizes, but they all have one thing in common: they have two terminals that allow electricity to flow through the capacitor being tested. The tester measures the amount of current that flows through the capacitor and uses this information to calculate the capacitance.
Most capacitor testers also have a built-in resistor that allows them to test capacitors of different sizes. By changing the value of the resistor, the tester can accurately measure capacitors from 1 picofarad (pF) to 100 microfarads (μF).