Briefly describe the basic operation method of using a multimeter to measure resistance
1. Firstly, connect the probes. The selection of the multimeter can be either a pointer or a digital display. Insert the red probe into the V Ω range and the black probe into the COM end to ensure that the multimeter is functioning properly.
2. Rotate the multimeter gear to measure resistance. If you are unsure of 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 gear, so that the instrument pointer indicates at least 1/2 of the full scale. After selecting the appropriate magnification range, touch the two probes to make the pointer point to zero. If the pointer deviates from zero, adjust the "zero adjustment" knob to make the pointer return to zero to ensure accurate measurement results.
3. Connect the two segments of the resistor, connect the probes randomly without any positive or negative distinction, and make sure to ensure good contact.
4. Read the data displayed on the multimeter. If no data appears on the multimeter, it is possible that the resistor is broken. Of course, there is also a possibility that the range is insufficient and needs to be replaced.
5. Increase the range. If there is still no data, it can only indicate that the resistor is broken. If there is data output, pay attention to adding the unit of gear.
The basic principle of a multimeter:
It uses a sensitive magneto electric DC ammeter (microampere meter) as the meter head. When a small current passes through the meter, there will be a current indication. But the meter head cannot pass high currents, so it is necessary to shunt or reduce the voltage by connecting some resistors in parallel or series on the meter head, in order to measure the current, voltage, and resistance in the circuit.
Precautions for using a multimeter:
1. Before using a multimeter, it is necessary to perform a "mechanical zeroing", which means that when there is no measured power, the multimeter pointer should be placed at the zero voltage or zero current position.
2. During the use of a multimeter, do not touch the metal part of the probe with your hands. This ensures accurate measurement and personal safety.
3. When measuring a certain amount of electricity, it is not advisable to shift gears at the same time, especially when measuring high voltage or high current. Otherwise, it will damage the multimeter. If you need to shift gears, disconnect the probe first and then measure after shifting gears.
4. When using a multimeter, it must be placed horizontally to avoid errors. At the same time, it is also important to avoid the influence of external magnetic fields on the multimeter.
