Working Principle of Digital Ground Resistance Tester:
The working principle of the digital ground resistance tester is that the internal DC/AC converter converts DC into low-frequency constant current of AC, which forms a loop through the auxiliary grounding electrode C and the tested object E. An AC voltage drop is generated on the tested object, which is sent to the AC amplifier through the auxiliary grounding electrode P for amplification, and then after detection, it is sent to the meter for display. With the help of the rate switch, three different ranges can be obtained: 0-2Ω, 0-20Ω, and 0-200Ω.
4. Precautions and Maintenance of Digital Ground Resistance Tester
1. When measuring the protective grounding resistance with the digital ground resistance tester, be sure to disconnect the connection point between the electrical equipment and the power supply. When measuring grounding resistance less than 1Ω, use dedicated wires to connect to the grounding body respectively, with C2 on the outside and P2 on the inside (as shown in Figure 4):
2. When storing and keeping this meter, pay attention to ambient temperature and humidity. It should be placed in a dry and ventilated place to avoid moisture, and should be protected from acids, alkalis, and corrosive gases. It must not be rained on, exposed to sunlight, or dropped.
3. When measuring the grounding resistance of a large grounding grid, the general wiring method cannot be used. Instead, refer to the regulations in the ammeter and voltmeter measurement method to select the burial and insertion points.
4. When measuring grounding resistance, it is best to repeatedly measure 3-4 times in different directions and take the average value.
5. When the battery voltage of this meter is lower than 7.2V, the meter displays the undervoltage symbol "←", indicating insufficient battery voltage. At this time, plug in the power cord to charge, and the charging time is more than 4 hours (this machine has a built-in charger and is equipped with a dedicated power cord, so users do not need to configure a charger separately).
