Martindale PD690 proving unit produces 690V AC/DC to enable voltage indicators to be fully checked.
This unit is designed for indicators with 230V and 415/440V AC or DC detection ranges, such as the Martindale VI13700G.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.
Not designed for use with multimeters.