A digital earth resistance tester can be used for testing.
Grounding resistance meter is a portable meter specially designed for measuring grounding resistance, it can also be used to measure small resistance and soil resistivity. The earth resistance meter is mainly composed of hand-cranked alternator, current transformer, potentiometer and current detector.
Before the measurement, first of all, the two probe needle were inserted into the ground in the ground pole E, potentiometric probe needle P and current probe needle C into a straight line and 20 meters away from each other, P inserted in the E and C between, and then with a special wire will be E, P, C to the corresponding terminal of the meter. Disconnect the device from the grounding wire before use. Place the meter flat, and then perform mechanical zero calibration.
Earth shaking meter wiring: first of all in the distance from the measured grounding pole E 40 meters will be inserted into the soil current probe C depth of about 40cm, and then the potential probe P inserted in the measured grounding pole E and current probe C in the middle of the three in a straight line and each other 20 meters apart. Finally, the wire will be connected to the E end of the instrument E knob, the potential probe P and the instrument's P end of the connection, the current probe C and the instrument is connected to the C end.
Measurement of less than 1 Ω grounding resistance wiring diagram in Figure 2 will be on the instrument 2 E knob wires were connected to the grounding body to be measured, to eliminate the measurement of connecting wire resistance on the measurement of the results of the introduction of additional errors.