How to use and function of ground resistance tester

The ground resistance tester is a new type of digital ground resistance tester that abandons the traditional manual hand-cranked power generation working mode, adopts advanced large-scale integrated circuits, and uses DC/AC conversion technology to combine the three-terminal and four-terminal measurement methods into one model. At present, advanced ground resistance testers can meet all grounding measurement requirements. Using the new clamp method, there is no need to pile and lay out lines for online direct measurement. A powerful ground resistance tester is controlled by a microprocessor, which can automatically detect the connection status of each interface and the interference voltage and interference frequency of the ground network, and has unique functions such as value retention and intelligent prompts.

Measurement steps:

(1) Insert two grounding probes into the ground at a distance of 20m and 40m from the grounding body respectively along the radial direction of the grounding body, with an insertion depth of 400mm.

(2) Place the ground resistance meter flat near the grounding body and connect the wires.

(3) After placing the measuring instrument horizontally, check whether the pointer of the galvanometer points to the center line. If not, adjust the "zero adjuster" so that the pointer of the measuring instrument points to the center line.

(4) Set the "magnification scale" (or coarse adjustment knob) to the maximum magnification and slowly turn the generator handle (the pointer begins to deviate). At the same time, turn the "measurement dial" (or fine adjustment knob) so that the galvanometer pointer points to the center line.

(5) When the pointer of the galvanometer is close to balance (the pointer is close to the center line), speed up the crank to make its speed reach above 120r/min, and at the same time adjust the "measuring dial" so that the pointer points to the center line.

(6) If the reading on the "measurement scale" is too small (less than 1) and difficult to read accurately, it means that the magnification scale is too large. In this case, the "magnification scale" should be set to a smaller multiple, and the "measurement scale" should be readjusted so that the pointer points to the center line and an accurate reading can be obtained.

(7) Calculate the measurement result, that is, R ground = “magnification scale” reading × “measurement scale” reading.

effect:

1. Accurately measure the grounding impedance, grounding resistance and grounding reactance of large grounding grids

2. Accurately measure the surface potential gradient in large grounding grid areas

3. Accurately measure the contact potential difference, contact voltage, step potential difference and step voltage of large grounding grids

4. Accurately measure the transfer potential of large grounding grids

5. Measure the on-resistance of the grounding lead; measure the soil resistivity

It is suitable for measuring the grounding resistance of various devices in the power, post and telecommunications, railways, communications, mining and other departments, as well as measuring the resistance value of low-resistance conductors; this meter can also measure soil resistivity and ground voltage.