Digital grounding resistance measuring instrumentAbandoning the traditional manual hand cranked power generation method, adopting medium to large-scale integrated circuits, and applying DC/AC conversion technology to merge the three terminal and four terminal measurement methods into a new type of grounding resistance measuring instrument. The working principle is that the DC/AC converter inside the machine converts DC into AC low-frequency constant current, which forms a circuit through the auxiliary grounding electrode C and the measured object E. An AC voltage drop is generated on the measured object, which is amplified by the AC amplifier through the auxiliary grounding electrode P, and then detected and displayed on the meter head. With the help of a multiplier switch, three different limits can be obtained: 0-2 Ω, 0-20 Ω, and 0-200 Ω.
This table is applicable for measuring the grounding resistance of various devices and measuring the resistance values of low resistance conductors in departments such as power, postal and telecommunications, railway, communication, and mining; This table can also measure soil resistivity and ground voltage.
Notes:
1. When storing and storing this table, attention should be paid to the ambient temperature and humidity. It is advisable to place it in a dry and ventilated place to avoid moisture and prevent acid, alkali, and corrosive gases.
2. When measuring the protective grounding resistance, be sure to disconnect the electrical equipment from the power supply connection point. When measuring grounding resistance less than 1 Ω, wires should be connected to the grounding body separately, with C2 on the outer side and P2 on the inner side.
3. When measuring the grounding resistance of a large grounding grid, it is not possible to measure it according to the general wiring method. The buried insertion point can be selected according to the provisions of the ammeter and voltmeter measurement methods.
4. Measure the ground resistance 3-4 times in different directions and take the average value.
5. This instrument is designed for both AC and DC use. When not connected to AC power, the instrument is powered by a battery. When connected to AC power, AC power is preferred.
6. When the top left corner of the header displays "←", it indicates that the battery voltage is insufficient and a new battery should be replaced. When the instrument is not in use for a long time, all batteries should be removed to avoid rusting the instrument.