Measuring low resistance

Even when high levels of electrical noise are present, Megger’s new DLRO2X digital low-resistance ohmmeter can be deliver dependable results. This versatile handheld instrument also offers users four test modes – normal, fast/long lead, inductive resistance and a new noise rejection test mode – and has facilities for saving test results internally for later downloading via a USB memory stick. A further innovative feature is an integral ‘difference meter’ function which allows rapid comparisons to be made between measurements.

The DLRO2X is suitable for an exceptionally wide range of applications, including checking the integrity of weld joints, measuring the resistance of lightning protection systems in wind turbines, measuring continuity in PV farms, testing high current track connections in railway and tram systems, verifying cable resistance, checking battery connections in electric vehicles, and many more.

In normal mode, users of the DLRO2X can set a maximum test current up to 2A and select either unidirectional or bidirectional testing. This mode provides maximum flexibility and the measuring range is 1µΩ to 2000Ω. In fast/long lead mode the maximum test current is 1A, and measurements displayed only in mΩ. Settings are automatically optimised to deliver fast results and, where necessary, to allow the use of long test leads. Results are displayed in milliohms.

In inductive resistance mode, the test current is fixed at 1A maximum and, to save time, the test terminates automatically when the current stabilises. In the new noise rejection range the maximum test current is 1A, and is applied continuously to allow a stream of measurements to be fed into the Confidence Meter. This feature even allows the instrument to provide accurate measurements while subjected to high levels of random noise.