The Megger DET20C measures earth/ground resistance and current flow using clamp-on technology. The DET20C induces a test current into the system without the need to disturb existing connections. It is a useful addition to the more traditional methods of earth/ground resistance testing that may require disconnection and the use of stakes or ground rods. Simply clamp around the conductor or stake/rod and measure the resistance to ground fast and accurately. The DET20C can also be used to measure earth/ground resistance in multiple loop installations without disconnecting the earth or ground. This allows the user to perform the test quickly and easily in total safety, with the added convenience of having a single point of measurement to read the earth/ground resistance. The DET20C also provides a true RMS current measurement reading to better indicate potential measurement problems and provide a useful overview of the dynamics of the general earth/ground system. It is rugged, compact and has configurable audible alarms. It also features auto shutdown (which is configurable), data storage and self-calibration on power-up, and is supplied with a calibration loop. The DET20C also comes with a RS232 interface cable and is compatible with Megger Download Manager Software (included) allowing further analysis and storage of data.