AEMC Ground Tester 4620-150 4-Point Ground Earth Resistance Tester performs ground resistance and soil resistivity tests. This direct reading testers measures from 0 to 2000O, and is auto-ranging, so it automatically seeks outs the optimum measurement range. The Digital Ground Resistance Tester Model 4620 is rugged, easy-to-use and is ideal for maintenance crews performing numerous tests. It exceeds mechanical and safety specifications for shock, vibration and drop tests called out in IEC standards. It is designed to reject high levels of interference, so it can be used under difficult conditions such as high stray currents that normally affect accuracy.