How does a multimeter measure current, voltage and resistance?
A multimeter is a multi-functional measuring meter. It can measure current and voltage, as well as resistance and other values, but the method of use is more complicated. So, how to use a multimeter will be introduced to you below.
How to use a multimeter
Measurement of voltage:
1. Measurement of DC voltage: First insert the black test lead into the [com] hole and the red test lead into the [VΩ];
2. Select the knob on the multimeter to a range larger than the estimated value (note: the values on the dial are the maximum range, [V-] represents the DC voltage range, [V~] represents the AC voltage range, [A] is the current gear), then connect the test leads to both ends of the power supply or battery;
3. Keep the contact stable. The value can be read directly from the display. If it is displayed as [1], it means that the range is too small, so it is necessary to increase the 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 the actual power supply polarity. At this time, the red test lead is connected to the negative pole;
4. 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 range [V~]. There is no positive or negative distinction between AC voltage, and the measurement method is the same as before. Regardless of whether you are measuring AC or DC voltage, you must pay attention to personal safety and do not touch the metal parts of the test leads with your hands;
Measurement of current:
1. Measurement of DC current. First insert the black test lead into the [com] hole. If you measure a current greater than 200mA, insert the red test lead into the [10A] jack and turn the knob to the DC [10A] position; if you measure 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. After adjustment, you can start measuring. Insert the multimeter into the circuit, keep it stable, and you can take a reading. If it displays [1], then the range needs to be increased; if - appears on the left side of the value, it means that the current flows from the black test lead into the multimeter;
2. Measurement of AC 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;
Measurement of resistance:
Insert the test leads into the [com] and [VΩ] holes, turn the knob to the required range in [Ω], and connect the test leads to both ends of the resistor. You can touch the resistor with one hand during measurement, but do not touch the two ends. Touching both ends of the resistor with one hand at the same time will affect the measurement accuracy. When reading, keep the test lead and the resistor in good contact; note: the unit is [Ω] at the [200] level, the unit is [KΩ] at the [2K] to [200K] level, and the unit above [2M] is 【MΩ】；
