The composition and functions of each part of a multimeter
The multimeter is composed of three parts: mechanical part, display part, and electrical part. The mechanical part includes: shell, gear knob and brush, etc. The display part is the meter head. The electrical part consists of measuring circuit board, potentiometer, resistor, Composed of diodes, capacitors and other parts.
Functions of various parts of the multimeter
(1) Header
The meter head of the 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 meter is a multimeter that can measure current, voltage and resistance. There are multiple scale lines printed on the dial. The one marked with "Ω" on the right end is the resistance scale line. The right end is zero and the left end is ∞. The scale value distribution is uneven. The symbol "-" or "DC" represents direct current, "~" or "AC" represents alternating current, and "~" represents the scale line shared by AC and DC. The several rows of numbers under the scale line are the scale values corresponding to the different gears of the selector switch.
There is also a mechanical zero adjustment knob on the watch head to correct the pointer to point to zero at the left end.
(2) Selector switch
The multimeter's selector switch is a multi-position rotary switch. Used to select measurement items and range. (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) Test leads and test lead sockets
The pens are divided into red and black. When using, insert the red test lead into the jack marked with "+" and the black test lead into the jack marked with "-".
