The Digital Ground Resistance Tester Model 4630 performs ground resistance and soil resistivity tests. This direct reading tester measures from 0 to 2000Ω, and is auto-ranging, so it automatically seeks outs the optimum measurement range. The Model 4630 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 specified 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. The Model 4630 is powered by 9.6V, 3.5 Ah NiMH rechargeable batteries. A built-in recharge circuit, powered from 120/230V 50/60Hz line, also provides for testing while recharging.Includes:Digital Ground Resistance TesterUser manualIt 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. The Model 4630 is powered by 9.6V, 3.5 Ah NiMH rechargeable batteries. A built-in recharge circuit, powered from 120/230V 50/60Hz line, also provides for testing while recharging.Features:Measures soil resistivity (4-Point) methodMeasures ground resistance (2- and 3-Point) Fall-of-Potential methodStep voltage tests and touch potential measurementsAuto-Ranging: automatically selects the optimum rangeDesigned to reject high levels of noise interferenceExtremely simple to operate: connect - press - readLED on faceplate informs operator of high input noise, high auxiliary rod resistance and fault connectionsAC powered with rechargeable NiMH batteriesRugged, dustproof and rainproof field caseCan also be used for continuity tests on bondingColor-coded terminalsApplications:Three-Point measurements of resistance to ground of ground rods and grids. Three-Point measurements are generally used when the electrode or grid can be easily disconnected, if corrosion is suspected, or in circumstances where ground faults are unlikely to occurFour-Point tests or soil resistivity measurements. Locating areas of lowest soil resistivity is essential for achieving an economical grounding installationTouch potential measurements, an alternative to 3-Point tests in evaluating electrical safety. This test is recommended when the ground cannot be disconnected, where ground faults are highly likely to occur, or when the "footprint" of grounded equipment is comparable to the size of the ground to be tested.