Using a voltage indicator without first proving it is working correctly has proved fatal. The Martindale PD690 is a 700V AC proving unit, designed to enable voltage indicators to be fully checked, in compliance with Health & Safety recommendations.
This unit is designed for indicators with 230V and 415/440V AC detection ranges, such as the Martindale VI13700. The proving unit is one of the few designs to check indicators with ranges above 250V.
The PD690 can also check Drummond and other filament test lamps as its output is sufficient to illuminate the bulb. This model is not designed for use with multimeters.