How to Measure Voltage and Current by Digital Multimeter
How to measure voltage range with digital multimeter
1. Measurement of DC voltage, such as battery, Walkman power supply, etc. First insert the black test lead into the "com" hole, and the red test lead into the "V Ω". Select the knob to a range larger than the estimated value (note: the values on the dial are the maximum range, "V-" indicates the DC voltage range, "V～" indicates the AC voltage range, and "A" is the current range), and then turn the Connect the test lead to the power supply or both ends of the battery; keep the contact stable. The value can be read directly from the display screen, if it is displayed as "1.", it means that the measuring range is too small, then it is necessary to increase the measuring range before measuring industrial electrical appliances. If "-" appears on the left side of the value, it means that the polarity of the test lead is opposite to that of the actual power supply. At this time, the red test lead is connected to the negative pole.
2. Measurement of AC voltage. The test lead jack is the same as the measurement of DC voltage, but the knob should be turned to the required range at the AC gear "V~". There is no difference between positive and negative AC voltage, and the measurement method is the same as before. Regardless of measuring AC or DC voltage, pay attention to personal safety, and do not touch the metal part of the test lead with your hands.
The method of digital multimeter measuring current range
1. Measurement of DC current. First insert the black test lead into the "COM" hole. If measuring a current greater than 200mA, insert the red test lead into the "10A" jack and turn the knob to DC "10A"; if measuring a current less than 200mA, insert the red test lead into the "200mA" jack and turn the knob To a suitable range within DC 200mA. Once adjusted, it's time to measure. String the multimeter into the circuit, keep it stable, and you can read. If it is displayed as "1.", then increase the range; if "-" appears on the left side of the value, it means that the current flows from the black test lead into the multimeter.
Measurement of alternating current. The measurement method is the same as 1, but the gear should be set to the AC gear. After the current measurement is completed, the red pen should be inserted back into the "VΩ" hole. If you forget this step and directly measure the voltage, haha! Your watch or power supply will "go up into the sky in a wisp of smoke" - scrapped!
