Use and Maintenance of Multimeters
The circuit of a multimeter is more complex than that of a wheel, and it is frequently used, resulting in more opportunities for malfunctions and damage. Therefore, special attention should be paid to:
(1) When measuring voltage, the meter should be connected in parallel with the circuit being measured. If the measured voltage is DC, attention should also be paid to the positive and negative poles.
(2) When measuring current, the meter should be connected in series with the circuit being measured, while paying attention to the positive and negative poles.
(3) If the positive and negative poles of the circuit being tested are not clear, the transfer switch can be placed on the highest range, and then the appropriate range will be used for measurement.
(4) If the positive and negative poles of the circuit being tested are not clear, the conversion switch can be placed on the highest range, and then a calibration rod can be touched on either pole of the circuit being tested. The other calibration rod can be gently touched on the other pole of the circuit being tested and immediately removed. Observe the direction of pointer deflection, and then determine its positive and negative poles.
(5) If it is unclear whether the voltage of the circuit being tested is DC or AC, it should be tested using AC gear first, and then switched to DC gear for testing. When testing with a DC range, if the meter does not read, it is AC, otherwise it is DC.
(6) When measuring current or resistance on an electric meter, it is absolutely not allowed to mistakenly measure voltage, otherwise the meter head may suffer serious damage.
(7) When adjusting the resistance, the power supply of the circuit being tested must be cut off to avoid damage to the meter head. It is best to solder a wire head from the original circuit before measuring the measured resistance. This not only protects the meter head but also ensures accurate measurement. If there is capacitance in the tested circuit, the capacitance should be discharged first, otherwise it may also damage the instrument.
(8) After the measurement is completed, the conversion switch should be set to the maximum range for AC voltage measurement to avoid damage caused by accidental misuse in the next use.
