Proposition of New Standard Curves for Analysis of ρ-a Curves Obtained with Wenner's Four Electrodes Arrangement

Abstract

For the design of a grounding electrode, the ground configuration at an intended site for the electrode needs to be clear. For this purpose, in many cases, ρ-a curves from the measured results with Wenner's four electrodes arrangement are analysed by Sundberg's standard curves. But analysed results for ρ2 have not been sufficient especially when thicknesses of the second ground layers are small.
In this paper, new standard curves are proposed for analysis of ρ-a curves. Sundberg's curves have one parameter of ρ2/ρ1. However, the new standard curves have two other parameters of ρ3/ρ2 and h2/h1, in addition to ρ2/ρl. Accordingly the new standard curves resemble ρ-a curves for three-layer grounds in shape.
First constitutions of the new standard curves are described. Then many model ρ-a curves are analysed for ρ1, h1 and ρ2 by the new standard curves and also by Sundberg's curves. It is found that the new curves are better than or as good as Sundberg's curves, and the errors of the results for ρ2 analysed by the new curves are less than 12%.