Senses the steady state electrostatic field produced by ac voltage through insulation without requiring contact to the bare conductor. A red glow at the tip and a beeping noise (if not switched OFF) indicates the presence of voltage.
Voltage sensing ranges
Nominally, 90 V AC to 1000 V AC or 200 V AC to 1000 V AC depending on model, 45 Hz to 405 Hz; also a 20 V to 90 V control circuit model