Novel calibration method for fine soil electrical resistivity based on van der Pauw configuration

Abstract Soil electrical resistivity (ER) serves as an important parameter for indirectly monitoring various physical properties. The Miller box, based on Ohm’s Law, is commonly employed to measure resistivity. However, its probes tend to insert destructively into the soil sample. Van der Pauw (vdP) method is a classical, non-destructive technique used for measuring the ER of thin samples. Applying the vdP method to soil, which is a non-flat sample, presents certain challenges. In this paper, a novel soil resistivity calibration method (vdP box) is developed based on the vdP method, with consideration given to thickness extension. The relative resistivity error between the VDP box and Miller box for fine soil is less than 1% with various diameters and moisture content, which verified the accuracy and stability of the new device. This device achieves simple, fast, and non-destructive testing of soil resistivity and provides a novel method to study other properties of soil indirectly through resistivity.