Introduction of various measurement methods of ground resistance tester! There are usually the following types: single-clamp method, double-clamp method, two-wire method, three-wire method, and four-wire method. Each grounding resistance tester has its own characteristics. In actual measurement, try to choose the correct method to make the measurement result accurate.

1. Single clamp method

Applicable conditions: Measure the grounding resistance of each grounding point in the multi-point grounding, and the grounding connection cannot be disconnected to prevent danger.

Scope of application: Multi-point grounding, can not be disconnected, measure the resistance of each grounding point.

Wiring mode: use a current clamp to monitor the current on the measured grounding point.

2. Double clamp method

Applicable conditions: multi-point grounding, no auxiliary ground piles, and single grounding measurement.

Wiring method: Use the current clamp specified by the manufacturer to connect to the corresponding socket, and clamp the two clamps on the grounding conductor. The distance between the two clamps should be greater than 0.25 meters.

HZ2571 Ground Resistance Tester

HZ2571 Ground Resistance Tester

3. Two-line method

Suitable conditions: there must be a known well grounded ground, such as PEN, etc. The measured result is the sum of the resistance of the measured ground and the known ground. If the known ground is much smaller than the resistance of the measured ground, the measurement result can be used as the result of the measured ground.

Scope of application: areas with dense buildings or cement grounds that cannot be sealed and cannot be piled.

Wiring mode: E+ES is connected to the measured ground, H+S is connected to the known ground.

4. Three-line method

Suitable conditions: There must be two ground rods: an auxiliary ground and a detection electrode. The distance between each ground electrode is not less than 20 meters. The principle is to add a current between the auxiliary ground and the measured ground to measure the voltage drop between the measured ground and the probe electrode. The measurement result includes the resistance of the measuring cable itself.

Scope of application: foundation grounding, construction site grounding and lightning ball type lightning rod QPZ grounding.

Wiring mode: S is connected to the detection electrode, H is connected to the auxiliary ground, and E and ES are connected to the ground to be measured.

5. Four-wire method

Basically the same as the three-wire method, it replaces the three-wire method when measuring low ground resistance and eliminating the influence of the measurement cable resistance on the measurement results. E and ES must be directly connected to the measured ground separately during measurement. This method is highly accurate among all ground resistance measurement methods.