HORIZONTAL SOUNDING: a series of measurements must be performed by moving alongside a straight line; the line formed because of the 4 electrodes getting possibly parallel or perpendicular to the axis of this progression. Earthing Solutions takes advantage of the hardwearing, trustworthy Megger DET4TD device for Wenner 4-pole soil resistivity https://foundationpiletestingbd32842.rimmablog.com/31534919/getting-my-soil-resistivity-testing-laboratories-bd-to-work