The Extech 382357 clamp-on ground resistance tester measures ground resistance without auxiliary ground rods. It measures resistance from 0.03Ω to 1500Ω and True RMS AC leakage current from 0.2mA to 30.00A. A 0.9-inch jaw accommodates large ground rods, and automatic self-calibration occurs when powered on.

Programmable data logging with 116 data points, programmable hi/lo alarms, and an included resistance checkplate verify meter accuracy. Electrical noise detection prevents inaccurate readings. Applications include cellular/communication tower ground grids, utility transmission systems, substations, factories, and office buildings.