Adjustment method and precautions before using the multimeter
1. In the process of using the multimeter, do not touch the metal part of the test lead with your hands, so that on the one hand, it can ensure the accuracy of the measurement, and on the other hand, it can also ensure personal safety.
2. When measuring a certain amount of electricity, you should not change gears while measuring, especially when measuring high voltage or high current, you should pay more attention, otherwise the multimeter will be damaged. If you need to change gears. The test leads should be disconnected first. Measure after changing gears.
3. The multimeter must be placed horizontally when in use. so as not to cause errors. At the same time, care should be taken to avoid the influence of external magnetic fields on the multimeter.
4. After using the multimeter, the transfer switch should be placed in the maximum gear of the AC voltage. If it is not used for a long time, the battery inside the multimeter should also be taken out to avoid corrosion of other components in the meter after the battery leaks.
That is, before measuring the electric quantity to be measured, make the pointer of the multimeter point to the position of zero voltage or zero current.
Mechanical zero adjustment refers to adjusting the torque of the hairspring of the meter head without power on. The pointer may change due to movement, temperature changes, etc.; under normal circumstances, this does not need to be adjusted frequently. The key point is to check and adjust. If there is no change, no adjustment .
For the zero adjustment of the ohm block of the multimeter, it actually reaches the full bias current through the current of the meter head, and there is an adjustable resistor in the ohm block, I =E/(R+r), R is the resistance value of the adjustable resistor, r is the internal resistance of the power supply. When R reaches a certain value, I can reach the full bias current. Then receive the test electrode Rx, then I =E/(Rs+R+r), different currents correspond to different resistances to be tested.
①Put the gear adjustment knob to the ΩX1 gear.
②Connect the red test lead to the "+" terminal and the black test lead to the "-" terminal.
③Short-connect the measuring ends of the test leads (connect them together), and observe whether the hands point to the "Ω" on the scale line, as shown in Figure 1-4 above, if it does not point to zero, adjust the "ohm zero adjustment" knob to make it point to zero .
④ When adjusting the knob of "ohm adjustment, etc." and the pointer cannot point to 0", it indicates that the battery in the watch is low, and the battery in the watch should be replaced.
⑤ The highest magnification gear of many multimeter resistors, and a high-voltage battery (9V or 15V), should be replaced according to the instructions. Corresponding batteries are required to use this file.
