3- and 4-pole Fall-of-Potential; earth resistance loop testing Provides R* measurement that calculates earth ground impedance at 55 Hz to more accurately reflect the earth ground resistance that a fault-to earth ground would see Includes USB port for data storage and transfer Features IP56 rating for outdoor use A unique earth ground tester that performs testing with and without stakes Selective earth ground rod testing using 1 clamp Stakeless earth ground rod testing using 2 clamps Features Automatic Frequency Control (AFC) to minimize the effect of interference