Continuity tester

A continuity tester is an electrical test set, which indicates by means of an optical or acoustic signal as to whether two points are electrically connected together.

Continuity tester can be used, for example, to check the correct wiring of an installation or locate failures in an existing installation.

A continuity tester consists of two probes, between which it produces a harmless auxiliary or test voltage (usually 1.5 to 4.5 volts) by means of a built-in battery. In this series is in the machine, a warning lamp ( incandescent lamp or LED with series resistor) or an acoustic signal generator. If between the probes, an electrical connection, a current that the tester visually or by sound flows.

Often continuity tester are in the form of a thick pen and carry one of the probes fixedly mounted on one end. The second test port is partially provided with an alligator clip to work with one hand can.

Also, resistance testers can serve as a continuity tester, they often also possess a continuity tester function, in which they produce a beep when it falls below a certain resistance value.

Since the auxiliary voltage is a DC voltage, diodes also can use a continuity tester to check if their forward voltage less than the test voltage (battery voltage).