Summary and Tips for Using Digital Multimeters
Measurement of voltage
1. Measurement of DC voltage, such as batteries, portable audio power supplies, etc. Firstly, insert the black probe into the "com" hole and the red probe into the "V Ω" hole. Select the knob to a range larger than the estimated value (note: the values on the dial are all * large range, "V -" represents DC voltage range, "V~" represents AC voltage range, "A" represents current range), and then connect the probe to both ends of the power supply or battery; Maintain stable contact. The value can be directly read from the display screen. If it shows "1.", it indicates that the range is too small, and then a large range needs to be added before measurement. If a "-" appears on the left side of the value, it indicates that the polarity of the probe is opposite to the actual power polarity, and the red probe is connected to the negative terminal.
2. Measurement of AC voltage. The probe socket is the same as measuring DC voltage, but the knob should be turned to the required range at the AC gear "V~". There is no positive or negative distinction in AC voltage, and the measurement method is the same as before. Whether measuring AC or DC voltage, attention should be paid to personal safety and do not touch the metal part of the probe with your hands casually.
Measurement of current
1. Measurement of direct current. First, insert the black probe into the "COM" hole. If measuring a current greater than 200mA, insert the red probe into the "10A" socket and turn the knob to the DC "10A" position; If measuring a current less than 200mA, insert the red probe into the "200mA" socket and turn the knob to the appropriate range within 200mA DC. After adjustment, it can be measured. Connect the multimeter in series into the circuit, maintain stability, and the reading will be ready. If it displays as "1.", then the range needs to be increased; If a "-" appears on the left side of the value, it indicates that current is flowing from the black probe into the multimeter.
Measurement of AC current. The measurement method is the same as 1, but the gear should be set to AC gear. After measuring the current, the red pen should be inserted back into the "V Ω" hole. If you forget this step and directly measure the voltage, haha! Your watch or power supply will be scrapped!
