A non-contact voltage tester or detector is an electrical tester that helps to detect the presence of voltage. Voltage presence is useful information to have when troubleshooting or working on a failed asset. The first tool you’ll reach for is a non-contact voltage detector.
People refer to non-contact voltage testers in many ways. Some synonyms for non-contact voltage tester are:
Electricity tester pen
Voltage tester pen
Non-contact voltage detector
Voltage detector pen
AC voltage detector
Non-contact electrical tester
Electrical sniffer
Volt alert tester
Contactless voltage detector
Non-contact circuit tester
Non-contact voltage sensor
AC tester pen
No-touch voltage tester
Proximity voltage tester
Live wire tester pen
Non-contact power tester
Non-contact voltage checker
How do non-contact voltage testers work?
Non-contact voltage testers work by sensing a very small amount of current that is capacitively coupled from the live circuit to the tester and back to ground.