The sonel mru, 120hd earth resistance and soil resistivity meter boasts a strong and functional device characterised by particular resistance to difficult working conditions. This product is not considered afraid of dust or mud and performs excellently even in areas in locations that have an increased risk of splashing. Utilizing of the sonel mru, 120hd meter it is possible to perform earth resistance measurements using the 3, Pole and 4, Wire method. The instrument also allows measurements to be made using additional clamps multiple earthing, Without the need to disconnect the monitoring connections and measurements using the two, Clamp method. In the measurement, Some cases can be done without the application of auxiliary probes driven into the ground. Sonel mru, 120hd is a tool designed especially for earthing measurements in the power industry. Measuring range measurements aligned with en 61557 from 0. 30 . Other practical functions of the device are the capability of measure the resistivity of the earth and the continuity of protective and equalising connections. 3, Pole and 4, Wire method measurement of earthing systems using auxiliary probes 3, Pole method with clamp measurement of earthing systems with multiple earth electrodes two, Clamp method measurement of earthing system when the auxiliary probes cannot be used earth resistivity wenner method resistance of earth and compensatory conductors measured using current 200 ma with auto, Zero function meets the criteria of en 61557, 4