Grounding is the security measure representing electric connection with metal details or the earth. It is necessary to secure against defeat by current at any touches to the case of the electric device. By rules resistance of the grounding device periodically is measured. So, how to define grounding?
Instruction
1. Choose any device in which you wish to take measurements of resistance of a contour. Take the grounding measuring instrument. In this example the M416 measuring instrument and also all sequence of the actions made at measurements by it will be considered. This device most often meets on sale. Besides, it has a standard scheme, so, having understood its principle of work, you will deal with any other measuring instruments. M416 serves not only for determination of resistance of grounding, but also for determination of values of active resistance. Measurement range is rather high, it is from 0.1 to 1000 Ohms.
2. Before beginning to take measurements, it will be necessary to reduce as much as possible quantity of all possible factors which can cause additional errors. Take care of that close there were no powerful electric fields. Eliminate the possible sources causing hindrances. Remember that high-frequency radio interferences and hindrances of alternating current can be found out how the arrow of the device fluctuates. After that arrange the measuring instrument in strictly horizontal position.
3. Connect the device to food. For it three galvanic cells connected consistently are the power supply. Each of them of 1.5 V. The switch needs to be set to the position "Control of 5 Ohms". Then press the button. After that try to establish on a measuring scale in a zero mark an arrow of the indicator by means of easy rotation of the rheochord handle. Further it is necessary to check integrity of isolation on connecting wires. If everything is all right, then connect them to the device.
4. Now it is necessary to deepen the ground wire and the probe which serve as additional auxiliary electrodes, on depth approximately in a meter floor. Then attach to a wire. Install the switch in a position of "X1". Then press the button. Rotate the handle of "rheochord". Try to achieve it that the arrow of the indicator appeared in zero again. The result of measurement needs to be increased by this multiplier.