Circuit testers, also known as continuity testers, are inexpensive devices whose mechanisms are to locate or detectwhether electrical current is present and passing between two points. Often used in many applications, from automotive repair to residential and commercial electrical work, circuit testers consist of an indicator, usually tipped with alligator clips or two small leads, with a small light probe or bulbwhich lights up if a current is available. Other indicators come with a buzzer that will sound off, often termed as “buzzing out a circuit”. For more sophisticated applications of circuit testers, voltmeters or multimeters are some of the choices which aside from acting as circuit testers, they also display the voltage and resistance values.
When it comes to automobiles, circuit testers are of equal importance in checking for any critical electrical problems present and also to check for the availability of energy sources when installing or adding powered accessories to the vehicle. With that, batteries and spark plug wires can also be checked with the use of circuit testers for their current condition. Precautionary measures should be observed before checking electrical current systems with circuit testers so as to avoid any possible injuries caused by electrical shock; other circuit testers do not require batteries, others need fresh batteries for it to function.
In addition to safety reminders, one should also wear protective gloves specifically made out of materials that resist electrical currents, and also to unplug or turn the circuit power off at all times before performing testing procedures.