The measurement of the ground resistance of a large-scale grounding body, such as a structure grounding, requires the measurement of the ground resistance by the voltage drop method.
In the measurement of large-scale grounded objects such as structure grounding, a ground resistance meter causes potential interference between the measuring electrodes and finally errors in the measured values.
Therefore, the voltage (potential) drop method is used by installing the voltage electrode (point P) and current electrode (point C) with a long distance between them not to be interfered.
Since a large current of about 10 to 20 A is applied for measurement, it is essential to take sufficient safety measures.
Measuring instrument
Temporary auxiliary grounding electrode