Understanding Soil Resistivity Testing for Electrical Grounding

Soil resistivity testing is the single most critical factor in electrical grounding design. This is true when discussing simple electrical design, to dedicated low-resistance grounding systems, or to the far more complex issues involved in Ground Potential Rise (GPR) studies.

Electrical interference, causing unwanted signal noise to enter the meter. Metallic objects ‘short-cutting’ the electrical path from probe to probe. The rule of thumb here is that a clearance equal to the pin spacing should be maintained, between the measurement traverse and any parallel buried metallic structures.