The beeper-style electronic detectors provide audible and visual indication of the presence of phase-to-ground ac voltages, in accordance with ANSI C84.1-1982 standards.

The analog testers are ideally suited for outdoor testing of grounded and ungrounded systems, especially in areas where an LED lamp is not easily visible. The large, 3.5-in. (89-mm) analog scale is calibrated to indicate the presence of nominal system voltages; the tester cannot be used to determine an exact voltage measurement.