As testers, where should we start? The standards! For grounding testing, the industry reference is IEEE Standard 81, Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Grounding System. As with most standards, familiarity and interpretation are key. It can be a challenge to understand the intent, methods, and implementation of the prescribed testing. Fall of Potential (FOP) testing is a commonly specified test method to (attempt to) measure the impedance to…
