Martindale launches the PD230SRD and PD440SRDX Proving Units

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.

With this in mind, Martindale Electric has launched two new proving units, ideal for electricians and electrical contractors: the PD230SRD and the more advanced PD440SRDX. The PD230SRD Proving Unit is the ideal entry-level proving unit, to enable checking of basic voltage indicators. The PD440SRDX gives a higher voltage output of up to 440V, and also gives user additional testing features, for use when working with 18th Edition installation testers.

The PD230SRD is perfect for proving low and high impedance voltage indicators, test lamps and two pole testers. It includes an MG3 high-strength magnetic hanger, and comes in a tough over-moulded low profile design. It has a long battery life with a low battery indicator and an auto power-off function.

Any device that is used for detection of live voltage and proving dead should be tested before and after use to ensure the safety of the user, and the PD230SRD is the ideal basic proving device for this purpose. With a maximum of 230V output, the PD230SRD unit has three LED thresholds, a DC output mode, low battery indication and is high / low Z compatible. The PD440SRDX has additional features which include precise stepped voltage outputs, tailored to match two-pole tester thresholds reaching up to 440V. For the electrical installer the unit has the unique CALCHECK function already featured on the existing Martindale PD440SX, for verifying insulation and low resistance ranges on 18th Edition installation testers.

It is important to note that most multifunction testers have a maximum voltage measurement capability of 500V. The PD440SRDX 440V device is ideal for proving voltage measurement on this type of equipment within the maximum voltage range. Note that two pole indicators with a higher range, for example, 690V range should be proved at 690V – see other models in the range.

For more information on the Martindale Electric range of proving units, visit