Automatic Frequency Control (AFC) - identifies existing interference and chooses a measurement frequency to minimize its effect, providing more accurate earth ground valueR* measurement ? calculates earth ground impedance at 55 Hz to more accurately reflect the earth ground resistance that a fault-to earth ground would seeAdjustable limits - for quicker testing3- and 4-pole Fall-of-Potential, earth resistance loop testing4-pole Soil Resistivity testingSelective earth ground rod testing using 1 clampStakeless earth ground rod testing using 2 clampsIP56 rated for outdoor useRugged carrying caseUSB data storage and transfer