Functions of each part of the multimeter
(1) Header
The head of a multimeter is a sensitive ammeter. The dial on the meter head is printed with various symbols, scale lines, and numerical values (as shown in Figure 3-4 (B)). The symbol A - V - Ω indicates that this electric meter is a multimeter that can measure current, voltage, and resistance. There are multiple scale lines printed on the dial, among which the resistance scale line marked with "Ω" on the right end is zero, and the left end is ∞. The distribution of scale values is uneven. The symbol "-" or "DC" represents direct current, "~" or "AC" represents alternating current, and "~" represents the common scale line between alternating current and direct current. The lines below the scale line represent the scale values corresponding to the different gear positions of the selector switch.
There is also a mechanical zero adjustment knob on the header to correct the pointer to zero on the left end.
(2) Select switch
The selection switch of the multimeter is a multi gear rotary switch. Used to select measurement items and ranges. (as shown in Figure 3-4 (B)). General multimeter measurement items include: "mA"; DC current, "V": DC voltage, "V": AC voltage, "Ω": resistance. Each measurement item is divided into several different ranges for selection.
(3) Pen and pen socket
The pen is divided into two parts: red and black. When using, the red probe should be inserted into the socket marked with a "+" sign, and the black probe should be inserted into the socket marked with a "-" sign.
Precautions for using a multimeter
(1) Before using a multimeter, it is necessary to perform a "mechanical zeroing", which means that when there is no measured power, the multimeter pointer should be placed at the zero voltage or zero current position.
(2) During the use of a multimeter, do not touch the metal part of the probe with your hands. This ensures accurate measurement and personal safety.
(3) When measuring a certain amount of electricity, it is not advisable to shift gears at the same time, especially when measuring high voltage or high current. Otherwise, it will damage the multimeter. If you need to shift gears, disconnect the probe first and then measure after shifting gears.
(4) When using a multimeter, it must be placed horizontally to avoid errors. At the same time, it is also important to avoid the influence of external magnetic fields on the multimeter.
(5) After using the multimeter, the conversion switch should be set to the maximum AC voltage setting. If not used for a long time, the battery inside the multimeter should be removed to prevent corrosion of other components inside the meter.
