Test Methods:

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 crank to make it reach 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 re-adjusted 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.

Precautions:

1. The grounding circuit should 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 pole should be more than 10m away, and the voltage pole 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 wires should use well-insulated wires to avoid leakage.

7. There should be no electrolytic substances and rotting corpses at the test site, so as not to cause illusions.

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

9. Check the accuracy of the meter 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 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.