A voltage detector, also known as a voltage tester or test light, is an electronic testing device used to determine the presence of electricity in a conductor.
Voltage detectors can be both handheld or built into a circuit, depending on application requirement. Handheld detectors often resemble pens or flashlights, and are usually used for routine testing where efficiency is valued. Permanent detectors are hardwired into a control circuit and are used for safety purposes. If a machine is still drawing power when it shouldn’t be, for example, an inline detector can indicate this to operators.
Built-in detectors offer the most flexibility, in the voltage threshold required for detection, the maximum voltage the equipment can measure, and their integration into control systems like how far away from a machine they can be.