Wednesday, 7 December 2016
What is a Neon Glow or "Phase" Tester?
Newer type hand held electrical testers such as the Fluke VoltAlert use an electronic detection circuit which activates an LED when the tip of the tester is in close proximity to a live terminal or power cable, actual contact is not necessary. These testers are useful for detecting presence of voltage e.g in a power flex or on the output of a breaker. However if the tip is too far away, the LED may not light up, giving the false impression that a circuit is not live. So they should never be used to test for absence of voltage. A neon tester should be used for absolute certainty when testing (and the tester should be pre-checked by touching it against a live terminal , e.g. the outlet of a socket to ensure it is working properly).