Megger DET4TR2 4-Terminal Ground Resistance Tester with Rechargeable Battery, 0.01-20,000 Ohms Resistance Range Ground resistance tester measures earth ground resistance, soil resistivity, and ground voltage to evaluate electrical system safety Choice of 2-, 3-, or 4- pole ground resistance testing Maximum resistance input of 20,000 ohms for testing the resistivity of a range of soil types Voltmeter displays the ground voltage during use, which helps increase operator safety Meets International Electrotechnical Commission (IEC) safety standard 61010 and is certified for category IV installations up to 100V