Briefly describe the basic operation method of measuring resistance with multimeter
1. First connect the test leads. The multimeter can be a pointer or a digital display. The red test lead is inserted into the VΩ gear, and the black test lead is inserted into the COM terminal to ensure that the multimeter is normal.
2. Rotate the gear position of the multimeter, and use the resistance gear to measure the resistance. If you are not sure about the resistance value, you should first set the range switch to the maximum value, and then switch from the large range to the small range, so that the pointer of the meter indicates at full More than 1/2 of the scale is enough. After selecting the appropriate magnification gear, touch the two test leads so that the pointer points to the zero position. If the pointer deviates from the zero position, adjust the "zero adjustment" knob to make the pointer return to zero to ensure accurate measurement results.
3. To connect the two sections of the resistor, the test pen can be connected casually, there is no difference between positive and negative, and it must be ensured that the contact is good.
4. Read the data displayed by the multimeter. If there is no data on the multimeter, it may be that the resistor is broken. Of course, there is another possibility that the range is not enough. Replace the range.
5. Increase the range. If there is no data, it only means that the resistor is broken. If there is data output data, pay attention to add the unit of the gear.
The basic principle of multimeter:
It is to use a sensitive magnetoelectric DC ammeter (microampere meter) as the head. When a small current passes through the meter head, there will be a current indication. However, the meter head cannot pass a large current, so some resistors must be connected in parallel or in series on the meter head to shunt or lower the voltage, so as to measure the current, voltage and resistance in the circuit.
Precautions for multimeter use:
1. Before using the multimeter, "mechanical zero adjustment" should be performed first, that is, when there is no electricity to be measured, make the pointer of the multimeter point to the position of zero voltage or zero current.
2. 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.
3. When measuring a certain amount of electricity, it is not possible to change gears while measuring, especially when measuring high voltage or high current, more attention should be paid. Otherwise, the multimeter will be destroyed. If you need to change gears, you should disconnect the test leads first, and then measure after changing gears.
4. When using the multimeter, it must be placed horizontally to avoid errors. At the same time, attention should be paid to avoid the influence of the external magnetic field on the multimeter.
5. 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 prevent the battery from corroding other components in the meter.
focus on
1. If you are using an electronic multimeter, you must first adjust the gear to ohms.
2. Before use, make sure that the 1653 pointer is at 0Ω. Put the front ends of the red pen and the black pen together, which will cause a short circuit. If the pointer has not reached 0Ω, you can turn the zero adjustment knob Q to make the pointer point at zero ohms.
3. Insert the red test lead into the "VΩ" hole, insert the black test lead into the "COM" hole, and then select the resistance gear according to the resistance of the circuit to be tested.
4. To estimate the resistance value of the circuit, first adjust the multimeter to the maximum resistance position. If the digital display is small and not accurate enough during measurement, adjust the position.
5. The best reading is only two digits after the decimal point, and the data read out by adjusting to this gear is the most accurate.
