The Hioki FT6381 measures grounding resistance simply by clamping to multiple-grounded ground wires. No auxiliary grounding rod is needed, and there is no need to disconnect the ground wire from the grounding rod. The compact, low-profile sensor can be used to clamp ground wires with ease, and also provide AC current measurement functionality and can measure currents ranging from leakage current on the order of several mA to load currents of up to 60 A.