Multimeter composition and function of each part
Multimeter is a multi-function, multi-range portable electrical instrumentation, general multimeter can measure DC current, AC and DC voltage and resistance, some multimeters can also measure capacitance, power, transistor common-emitter DC amplification hFE and semiconductor parameters (such as β) and so on.
The composition of the multimeter
Multimeter by the mechanical part, display part, and electrical parts of the three major components, mechanical parts include: shell, gear knob and brush and other parts of the composition, the display part of the meter head, electrical part of the measurement circuit board, potentiometer, resistance, diode, capacitance and other parts of the composition.
Function of each part of the multimeter
(I) Meter head
The head of the multimeter is a sensitive ammeter. The dial on the head is printed with a variety of symbols, scales and values (Figure 3-4 (B)). The symbol A a V a Ω indicates that this meter is a multi-meter that can measure current, voltage and resistance. The dial is printed on a number of scales, including the right end labeled "Ω" is the resistance scale, the right end of which is zero, the left end of the ∞, the scale value distribution is uneven. Symbol "-" or "DC" indicates direct current, "~" or "AC " indicates AC, and "~" indicates a scale line shared by AC and DC. The lines 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 head of the meter to correct the pointer at the left end to point to the zero position.
(ii) Selection switch
Multimeter selector switch is a multi-position rotary switch. Used to select the measurement items and ranges. (As Figure 3 a 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.
(iii) Meter pens and meter pens jacks
Meter pen is divided into red, black two. When using the red pen should be inserted into the jack labeled "+" sign, the black pen into the jack labeled "-" sign.
