Author: Noyafa–CCTV Tester
Grounding resistance tester measurement method and precautions Grounding resistance tester, grounding resistance meter, and grounding meter are used to measure the grounding resistance value of various devices in electric power, communication, railway, industrial and mining enterprises and other departments. At the same time, the digital grounding resistance tester can measure the measurement methods and precautions of the soil grounding resistance tester Grounding resistance tester, grounding resistance meter, and grounding meter are used to measure the grounding resistance value of various devices in electric power, communication, railway, industrial and mining enterprises and other departments. At the same time, the digital ground resistance tester can measure soil resistivity and ground voltage.
Ground resistance tester test method: 1. Place the meter in a horizontal position and check whether the pointer of the galvanometer is on the center line, otherwise apply the zero adjuster to adjust it on the center line. 2. will“magnification scale”Set it to the maximum multiple, slowly turn the crank handle of the generator, and turn it at the same time“measuring dial”Make the needle of the galvanometer point on the center line. 3. When the pointer of the galvanometer is close to the balance, speed up the rotation speed of the generator crank to make it reach more than 120 rpm, and adjust it at the same time.“measuring dial”, so that the pointer points to the center line.
4. If“measuring dial”When the reading is less than 1, the magnification should be set to a smaller multiple, and the“measuring dial”to get the correct reading. 5. When filling in this record, the floor plan of the resistance test points should be attached, and the test points should be numbered sequentially. Ground resistance tester precautions: 1. The grounding line should be disconnected from the protected equipment to ensure the accuracy of the measurement results.
2. It cannot be measured after rain, when the soil absorbs too much water, and when the climate, temperature, pressure, etc. change sharply. 3. There should be no stray current and polarized soil near the measured earth pole. 4. The probe needle should be kept away from large metal objects such as underground pipes, cables, railways, etc. The current electrode should be kept away from more than 10m, and the voltage electrode should be kept away from more than 50m. If the above 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 ground 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 rotting corpses at the test site, so as not to cause misunderstandings.
8. The test should be carried out when the soil resistivity is high, such as early winter or summer dry season. 9. Check the accuracy of the instrument at any time, (send the measurement unit for testing and certification once a year) 10. When the sensitivity of the galvanometer is too high, the voltage electrode of the potential probe can be inserted into the soil shallower. When the sensitivity of the galvanometer is not enough, water can be injected along the probe to make it moist.
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