Multimeter use and maintenance
The circuit of the multimeter is more complicated than the wheel, and it is used frequently, so there are more chances of failure and damage. Therefore, special attention should be paid when using and maintaining:
(1) When measuring voltage, the ammeter should be connected in parallel with the circuit under test. If the measured voltage is DC, attention should also be paid to the positive and negative poles.
(2) When measuring the current, the ammeter should be connected in series with the circuit under test, and pay attention to the positive and negative poles at the same time.
(3) If you are not sure about the positive and negative poles of the circuit under test, you can put the changeover switch on the highest range, and then switch to the appropriate one for measurement.
(4) If you don't know the positive and negative poles of the circuit under test, you can put the changeover switch on the highest range, then touch a calibration rod to any pole of the circuit under test, and then put the other Take the calibration handle lightly on the other pole of the circuit under test and take it away immediately. Observe the deflection direction of the pointer, and then determine its positive and negative poles.
(5) If it is not clear whether the voltage of the circuit under test is DC or AC, it should be tested with AC gear first, and then tested with DC gear. When testing with DC gear, if the ammeter has no reading, it is AC, otherwise it is DC.
(6) When measuring current or resistance on the ammeter, the voltage must not be mismeasured, otherwise the meter head will suffer serious damage.
(7) When adjusting the resistance, the power supply of the circuit under test must be cut off to avoid damage to the meter head. It is best to measure the resistance to be measured after removing a wire from the original circuit. This can not only protect the meter head, but also ensure accurate measurement. If there is a capacitor in the circuit under test, the capacitor should be discharged first, otherwise the instrument will be damaged.
(8) After the measurement is completed, the switch should be turned to the maximum range for AC voltage measurement, so as to avoid damage caused by inadvertent misuse in the next use.
What kind of multimeter is generally used for mobile phone maintenance
A normal multimeter will do.
Multimeters, also known as multimeters, multimeters, three-meters, multimeters, etc., are indispensable measuring instruments in power electronics and other departments. Generally, the main purpose is to measure voltage, current and resistance. Multimeters are divided into pointer multimeters and digital multimeters according to the display mode. It is a multi-functional and multi-range measuring instrument. Generally, the multimeter can measure DC current, DC voltage, AC current, AC voltage, resistance and audio level, etc., and some can also measure AC current, capacitance, inductance and semiconductor. Some parameters (such as β) and so on.
