Probably the most significant development in test lamp design has been the move to high intensity LEDs, enabling the display of discrete voltages over a 360° viewing angle, even in bright sunlight for the most difficult of applications. The visibility from all angles is unique when compared to conventional two pole testers and makes for safer and easier voltage indication when carrying out safe isolation procedures.

The new generation retain all the existing benefits of the original test lamp with none of the drawbacks. The lighter and tougher designs operate without batteries, ranges or switches, making the Drummond MTL10 the most flexible and simplest way to prove dead before carrying out electrical maintenance.

With 4 distinctive bands of LED illumination, gone are the days of using lamp brightness as an indication of voltage level. The latest Drummond Test Lamps provide safe indication for voltages above 50, 100, 200 and 400 volts. The voltage levels allow accurate identification of potentially lethal voltages and enable electrical professionals to distinguish between 110V, 230V and phase to phase voltages in a 3 phase system.


Designed to optimise user safety, the innovative new range from Martindale Electric features a finger shield to minimise the risk of accidental contact with a live conductor and insulated probe tips, with only 4mm of exposed metal. The probes are detachable and can be replaced with right angled or straight probes from 3cm to 13cm long which can be rotated and locked in place to improve access to hard to reach measurement points in crowded cabinets.


As a further precautionary measure, the two layer double insulated cable with white inner insulation provides a clear warning of abrasion that might compromise user safety. Suitable for use in a variety of applications, the cable is also heat and oil resistant.

Troubleshooting phantom voltages

For troubleshooting demanding applications, for example, when live voltage indications appear to be present after isolating a circuit, the additional dual impedance functionality of the MTL20 can help get to the bottom of the problem quickly and safely.

It’s essential to identify if the voltage is hazardous, possibly back-fed, the result of an unwanted inter connection between circuits, or is a potentially harmless phantom voltage due to capacitive coupling. The MTL20 has the capability to simply dissipate induced phantom voltages by presenting a low impedance to the circuit when needed.



Featuring the same benefits as the MTL10, the MTL20 also incorporates 2 test buttons, one on the body of the unit and one on the probe. Simultaneous depression of both switches presents a low impedance to the circuit under test enabling the test lamp to draw a high current and dissipate phantom voltages, making it easy to differentiate between phantom voltages, due to capacitive coupling and true hazardous voltages. In order to prevent this from being done accidently, both buttons must be depressed to activate the low impedance feature.

Clearly if there is any doubt as to whether a voltage indication is hazardous live or interference / phantom after using a low impedance tester then alternative tests should also be performed.

New standards improve operator safety

It’s not just about functionality, there have been changes to safety standards for voltage indicators. The Drummond test lamps from Martindale Electric feature exceptional build quality and conform to the latest safety standards, as summarised in HSE GS38 Guidelines (2015) including BS EN61243-3 which came into force in 2013. Both models have a 600V CAT IV safety rating in accordance with BS-EN 61010-1 making them suitable for higher category supply side applications.


Available to purchase separately, or as part of a kit, the MTL10PD and MTL20PD include a proving unit and a combination carry case to ensure that electrical professionals always have the correct equipment to hand to implement safe isolation procedures before carrying out maintenance or installation work. A full range of test probe accessories are available for demanding applications
Widely specified by electricity utilities and other safety conscious organisations, the MTL10 and MTL20 come with a 2 year warranty.

Find out more about the full range of Drummond products and kits here