Martindale PD440SRDX – 440V AC/DC Proving Unit with 4 ranges & CALCHECK

  • Suitable for use with voltage indicators up to 440V
  • Switchable DC output mode via push button
  • CALCHECK for verification of resistance ranges on 18th Edition testers
  • Stepped voltage output matched to two-pole tester thresholds
  • Compatible with S-series magnetic hanger
  • Ideal for proving indicators and measurement devices up to 440V AC or DC and to check the operation of 18th Edition Installation Testers

EAN: 5036162188695 SKU: MARPD440SRDX Category:


Safe electrical working requires the use of a voltage indicator that has been proven with a suitable proving device before and after use to ensure the instrument is working correctly in accordance with the Electricity at Work Regulations.

The PD440SRDX is fast and easy to use, instantly supplying the full test voltage for both high and low impedance voltage indicators, test lamps and meters. It comes complete with an over moulded low-profile case with magnetic hanger.

The PD440SRDX has a unique CALCHECK feature making it easy to verify the insulation and low resistance ranges on 18th Edition multifunction testers, wherever you are working.


Output voltage 440V, 230V, 120V or 50V nominal
Output frequency DC or 50Hz nominal
Output loading See datasheet
Temperature (Operating & Storage) -10°C to 40°C
Humidity (Operating & Storage) max. 70% R.H.
Altitude up to 2000m
Pollution Degree 2
Power 6 x 1.5V, AA alkaline batteries (IEC LR6, NEDA 15A)
Dimensions 150 x 80 x 35mm
Weight 350g approx. with batteries
Insulation test resistance 0.5MΩ (max test voltage 1kV), 1.0MΩ (max test voltage 1kV)
Continuity test resistance 0.5Ω (max test current 200mA), 1.0Ω (max test current 200mA)



Maximum voltage output440V440V690V
LED voltage thresholds440V, 230V, 120V, 50V440V, 230V, 120V, 50V690V, 440V, 230V, 120V, 50V
AC output mode
DC output mode
Low Battery LED
High/Low Z compatible
CALCHECK resistance values
Colour-coded to match voltage indicators
Suitable forMultimeters, multifunction testers, 4-500V voltage
testers & Drummond test lamps
Multimeters, multifunction testers, 4-500V voltage
testers & Drummond test lamps
Multimeters, 690V voltage
testers & Drummond MTL15
test lamp