What is the reason why the DC meter needle rotates in the opposite direction when measuring with a multimeter
1. Functions of a pointer type multimeter
A pointer type multimeter, like other multifunctional meters, can measure various data such as DC current, DC voltage, AC current, AC voltage, resistance, etc.
2. How to achieve measurement of direct current
The head of a pointer type multimeter is actually a DC ammeter head. When measuring DC current, each gear position is equivalent to a resistor with different resistance values connected in parallel to the meter head, so as to shunt. When measuring DC voltage, a resistor with different resistance values is connected in series at the meter head to reduce voltage.
How to use a multimeter to measure
There are several steps to using a multimeter:
1. Before use, observation and mechanical zero adjustment are required to ensure that the pointer is on the zero scale before use.
2. Select the correct gear based on the measured data, such as measuring DC current, and selecting the gear at DCmA. It is necessary to choose the DC gear here because DC is DC and AC is AC, and the specific gear needs to be estimated based on the actual measurement data.
3. The red probe should be inserted at the "+" position, and the black probe should be inserted at the "com" port. During measurement, the red probe should be at the positive pole of the tested device, and the black probe should be at the negative pole of the tested device (this is the key point of this problem)
Because the characteristic of direct current is that its direction does not change over time, it has a direction. When measuring, it is important to pay attention to the direction. If measured as shown in the above figure, the reverse value will be displayed.
