Measuring the electrical resistivity of the Earth using a fabricated resistivity meter

Abstract

A four-electrode equipment which can be made available in the physics laboratory was designed and fabricated for measuring current and potential values so as to obtain the resistivity values. Readings taken from our chosen location using both Wenner and Schlumberger arrays were analysed. In the resistivity method, the Wenner configuration discriminates between resistivities of different geoelectric lateral layers while the Schlumberger configuration is used for the 'depth sounding'. The theory behind the resistivity method was introduced with some degree of sophistication. Experimentally determined values of depth to surface were correlated with the values determined from the excavated site and this gave a good correlation. It was observed that the resistivity value in the chosen location increases with the depth and the Schlumberger method was seen to have a greater penetration than the Wenner.