Structural Feature Comparison of Analog and Digital Multimeters
① Structural Composition of Analog Multimeters It usually consists of a meter movement, scale plate, housing, test leads, selector switch, zero-adjustment components, batteries, rectifiers and resistors. The meter movement generally adopts a magnetoelectric microampere DC ammeter with high internal resistance and high sensitivity. It is the main component of the multimeter and is composed of a pointer, magnetic circuit system, deflection system and scale plate. The scale plate is printed with various symbols, scale marks and values.
Before using the multimeter, you should correctly understand the meaning of various symbols and letters on the scale plate and how to read each scale.
The selector switch is used to select measurement items and ranges. Most multimeters have only one selector switch, while the Model 500 multimeter uses two selector switches in combination to select measurement items and ranges.
The "-" shaped mechanical zero-adjustment component at the center of the meter is used to adjust the resting position of the meter pointer (the pointer should rest at the "0" mark on the left side of the scale plate). The zero-adjustment knob is only used for resistance measurement.
A multimeter is equipped with two test leads. The black test lead connects to the "-" jack of the multimeter (it is internally connected to the positive pole of the built-in battery in the resistance range). The red test lead connects to the "+" jack of the multimeter (internally connected to the negative pole of the built-in battery in the resistance range), the 2500V voltage jack and the 5A current jack.
② Common Types of Analog Multimeters Common analog multimeters include MF-10, MF-30, MF-35, MF-47, MF-50 and Model 500, among others.
