Measurement of the resistance of physically large earth-electrode systems

In two earlier papers, methods were described by which the earth resistances of large electrode systems could be measured. A third method is described in this paper which has one advantage in that it is possible to check the reliability of the results obtained. It is based on the connection between the rate of change of the slope of the earth-resistance curve, and the distance of the potential electrode from the starting-point chosen to measure the distances to the potential and current electrodes. Examples are given of its application, both theoretical and practical, and the effect of nonhomogeneity of the soil is considered.