The Yokogawa 3235 Earth Tester is used as a convenient test set for simple, accurate measurements of earth resistance. Without  a hand-driven Generator, this instrument consists of battery-operated silicon-transistorized DC-AC inverter, An AC potentiometer measuring dial, and a galvanometer. Just push the push-button switch and move the dial so that the galvanometer shows balanced conditions. Then the resistance is directly read on the dial scale. A Wide range of earth resistance of 0 to 1kΩ can be measured by a single measuring Dial without range changeover. The earth voltage can also be measured on the galvanometer scale by positioning the selector switch.