How to Correctly Use a Multimeter for Measurement
The function of a multimeter for measuring DC current is to insert the red probe into the socket with a "+" sign and the black probe into the socket with a "-" sign.. Rotate the conversion knob to the desired range in the current function mode, and connect the probe in series with the circuit under test in the correct direction.
AC and DC voltage measurement: Insert the probe using the same method as above, turn the conversion knob to the desired position, and connect both ends of the probe to the two ends of the voltage to be measured.
Resistance measurement: Using the same method as above, insert the numbered probe and adjust the switch knob to the resistance position. First, short-circuit the two probes and deflect the pointer towards the full scale. Gently adjust the "Ω zeroing potentiometer" adjustment knob to make the pointer point to zero ohms, and then make contact between the two ends of the probe and the two ends of the measured resistor.
Proper use of multimeter: Only by using a multimeter correctly can the accuracy of measurement results be guaranteed without damaging the instrument. Attention should be paid when using: Before each measurement, the multimeter should be placed horizontally to observe whether the pointer points to zero. If the pointer does not point to zero, use a screwdriver to slightly adjust the mechanical zero screw of the meter head to make the pointer point to zero. The red and black probes should be correctly inserted into the multimeter socket. The rotary knob should be placed on the range gear of the electrical parameter to be measured, and must not be misplaced.
If the approximate range of the measured voltage and current values is unclear, the maximum voltage and current range on the table should be used first to predict, and then the appropriate measurement range should be used.
If you are not sure about the positive and negative polarity of the circuit being tested, you can place the conversion knob in the highest position, gently touch the circuit being tested with a probe during measurement, and observe the direction of pointer deflection to determine the
positive and negative polarity of the circuit. If it is unclear whether the voltage to be measured is AC or DC voltage, the highest gear of the AC voltage can be used to estimate the approximate range of voltage, and then the appropriate range of DC voltage gear can be used for measurement. If the meter head does not deflect at this time, it is determined that this voltage is AC voltage. If there is a reading, it is DC voltage.
When measuring current and voltage, the correct range should be set so that the pointer of the meter indicates a position greater than half of the range, and the resulting error is small.
