Martindale PD690S 690V Proving Unit

Martindale PD690S 690V Proving Unit

Martindale NC2 Non-contact Voltage Detector

Martindale NC2 Non-contact Voltage Detector

Martindale PD690SX Proving Unit with CALCHECK

£128.40 £107.00
Availability: In stock
Martindale PD690SX Proving Unit with CALCHECK
  • Safely proves the operation of voltage indicators and test lamps up to 690V
  • Unique CALCHECK function for multifunction installation tests
  • Individual LED indicators matched to voltage indicator thresholds
  • Long battery life with low battery indicator
  • Includes MAG3 high strength magnetic hanger
  • Colour coded for voltage output

Comes complete with a calibration Certificate Traceable to National Standards when purchased new.

Martindale PD690SX 50V/120V/230V/400V/690V AC Proving Unit with CALCHECK

Electricity at Work Regulations 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

The PD690SX has all the capabilities of the standard PD690S proving unit plus the CALCHECK feature for verifying the performance of installation testers and 5 stepped voltage thresholds matched to common two pole tester thresholds.

The CALCHECK feature makes it easy to verify the insulation and low resistance ranges on 18th Edition multifunction instruments and single function insulation testers on-site, making it ideal for identifying potential calibration issues with a multifunction tester prior to certifying a new wiring installation or carrying out a condition report. It’s also a valuable procedure recognised by electrical contractor assessment bodies.

It’s easy to keep a record of periodic CALCHECK results and equipment serial numbers for assessments using the form in the user guide or downloading copies from this page.  The individual reference resistance test pads with nominal values of 0.5Ωand 1.0Ω for continuity measurements and 0.5MΩ and 1.0MΩ for insulation resistance make it simple to check and identify calibration drift and remain confident in your test results wherever you are working.

The proving unit output voltages are stepped with individual LED indicators for each voltage threshold from 50V to 690V matched to common two pole tester thresholds, ideal for identifying potential voltage tester calibration issues. On contact, the proving unit outputs the highest voltage first instantaneously checking all LEDs up to 690V on the tester and proving the tester for safe isolation use, it then steps down through each level automatically. At the end of the proving test, a low resistance appears across the terminals to verify the continuity function of two pole testers.


Output voltage

690/400/230/100/50V nominal

Output frequency

50Hz nominal

Output loading

See datasheet

CALCHECK insulation test resistance

0.5MΩ (max test voltage 1kV)
1.0MΩ (max test voltage 1kV)

CALCHECK continuity test resistance

0.5Ω (max test current 200mA)
1.0Ω (max test current 200mA)

Temperature (Operating & Storage)

-10°C to 40°C

Humidity (Operating & Storage)

max. 70% R.H.


up to 2000m

Pollution Degree



6 x 1.5V, AA alkaline batteries (IEC LR6, NEDA 15A)


150 x 80 x 35mm


350g approx. with batteries



  • MG3 magnetic hanger
  • 6 x 1.5V AA alkaline batteries
  • Instruction manual

PD690SX proving unit comes complete with a Calibration Certificate Traceable to National Standards when purchased new.

Contact us for further information regarding PD690SX proving unit.

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