IEEE 81-2025

The test methods and techniques used to measure the electrical characteristics of the grounding system include the following topics:--Establishing safe testing conditions--Measuring earth electrical resistivity--Measuring the power system frequency resistance or impedance of the grounding system to remote earth--Measuring the transient (surge) impedance of the grounding system to remote earth--Measuring step and touch voltage--Verifying the integrity of the grounding system--Reviewing common methods and procedures for performing ground testing--Reviewing instrumentation characteristics and limitations--Reviewing various factors that can distort test measurements

This guide presents practical effective methods for measuring soil electrical resistivity and the condition and performance of grounding systems. Measurable parameters include grid resistance, grounding system impedance, ground potential rise (GPR), touch and step voltages, and current distributions in and from the system. These grounding grids and systems typically consist of interconnected grounding components ranging in complexity from a few ground rods to large grids with many ground rods or wells, buried conductors, and external ground connections. External ground connections may include overhead shield/ground/neutral wires, underground cable sheaths/neutrals, counterpoises, grid tie conductors, metallic pipes, and other connections that provide paths to remote earth.

Revision Standard - Active. Practical test methods and techniques are presented for measuring the electrical characteristics of grounding systems. Topics addressed include safety considerations, measuring earth resistivity, measuring the power system frequency resistance or impedance of the ground system to remote earth, measuring the transient or surge impedance of the ground system to remote earth, measuring touch and step voltages, verifying the integrity of the grounding system, reviewing common methods for performing ground testing, reviewing instrumentation characteristics and limitations, and reviewing various factors that can distort test measurements.