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Ground resistance tester test

time:2020/9/12   source:华天电力  reading:237 time

Test method of ground resistance tester

1. Place the meter in a horizontal position and check whether the pointer of the galvanometer is on the center line, otherwise, use a zero adjuster to adjust it on the center line.

2. Set the "magnification scale" to the maximum multiple, slowly turn the crank of the generator, and at the same time turn the "measurement dial" to make the pointer of the galvanometer point to the center line.

3. When the pointer of the galvanometer is close to balance, increase the rotation speed of the generator's shaker to make it more than 120 revolutions per minute, and adjust the "measurement dial" to make the pointer point on the center line.

4. If the reading of the "measurement dial" is less than 1, the magnification should be set to a smaller multiple, and the "measurement dial" should be readjusted to get the correct reading.

5. When filling in this record, a plan view of the resistance test points should be attached, and the test points should be numbered sequentially.

Earth Resistance Tester.png

Precautions for the use of grounding resistance tester

1. The grounding line must be disconnected from the protected equipment to ensure the accuracy of the measurement results.

2. It cannot be measured after it rains, when the soil absorbs too much water, and when the climate, temperature, pressure, etc. change drastically.

3. There should be no stray current and polarized soil near the pole to be measured.

4. The detection needle should be far away from large metal bodies such as underground water pipes, cables, railways, etc. The current electrode should be more than 10m away, and the voltage electrode should be more than 50m away. If the metal body is not connected to the grounding grid, the distance can be shortened by 1/2 ~1/3.

5. Pay attention to the position where the current electrode is inserted into the soil, and the grounding rod should be in a state of zero potential.

6. The connecting wire should use well-insulated wires to avoid leakage.

7. There should be no electrolytic substances and decaying corpses at the test site to avoid illusions.

8. The test should be carried out when the soil resistivity is large, such as early winter or summer dry season.

9. Check the accuracy of the instrument at any time, (send the unit of measurement for verification once a year)

10. When the sensitivity of the galvanometer is too high, the potential probe voltage electrode can be inserted into the soil shallowly. When the sensitivity of the galvanometer is not enough, water can be injected along the probe to make it wet.

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