Una procedura per semplificare la misura della resistenza di terra

The grounding resistance measurement of large installation requires that the current auxillary electrode be placed at a considerable distance from the electrode under test. That can involve difficulties and errors caused principally by the electromagnetic coupling effects between the conductors of the measurement circuit. In order to overcome such difficulties, the volt-amperometric method requiring that the auxiliary electrode be placed at a near distance to the electrode under test was considered. But, in this way, the correct position x//o of the voltage probe must be previously known. A systematic simulation analysis of some grounding grids of usual shape in non-homogeneous soil has allowed various error curves to be obtained. By means of these curves, the position X//o can be determined for any value of soil parameters