Definition and measurement of the earth resistance of an electrode covering a large area

Abstract

AbstractThe measurement of the earth resistance of an electrode by means of an auxiliary current electrode is affected by a systematic error with respect to the theoretical value, measured picking up the current at an infinite distance, due to the interaction between the two electrodes. The error increases with the ratio of the size of the test electrode to its distance from the auxiliary electrode. This paper suggests a method for the correction of the systematic error when the usual simplifying assumptions are made. The method itself is based on the replacement of the actual electric field, generated during the measurement, by the ideal electric field produced by punctiform electrodes. Its use allows the measurement of the earth resistance even with very short distances between the auxiliary electrode and the test electrode, taking into account the equivalent hemispherical electrodes.