On the Use and Maintenance of Multimeters
The basic structure of a multimeter, combined with the author's practical experience in multimeter calibration and maintenance, summarizes the precautions in the use of a multimeter, and proposes effective and fast maintenance methods and steps for different fault manifestations of the multimeter.
In the process of power production, a multimeter is an essential and important measurement tool because it is convenient to carry, has multiple ranges, and has a wide range of applications. It can be used for measuring DC current, DC voltage, AC voltage, DC resistance, and other aspects. Some can also measure audio power, level, inductance, capacitance, and so on. But it also has its drawbacks, which are the complex wiring, cumbersome use, frequent shifting of gears, and easy occurrence of faults and damage. So the correct use and maintenance of a multimeter are the key to extending its service life and ensuring measurement accuracy.
Composition of a multimeter
（1） Meter header. Usually, a magnetoelectric measuring mechanism is used as the head of a multimeter. Its full scale deflection current is generally several microamps to hundreds of microamps, and the smaller the full scale deflection current, the higher the sensitivity.
（2） Measure the circuit. The measurement line of a general multimeter consists of a multi range DC ammeter, a multi range DC voltmeter, a multi range AC voltmeter, and a multi range ohm. Some models of multimeter have a multi range AC current measurement line.
（3） Transfer switch. The selection of various measuring objects and ranges for a multimeter is achieved through a conversion switch, which has fixed and movable contact points. When the movable and fixed contact points are closed, the circuit can be connected.
