Multimeter is a magneto-electric instrument with rectifier, which can measure a variety of electrical parameters such as AC, DC current, voltage and resistance. For each electrical quantity, there are generally several ranges. Also known as multi-purpose meter or short for multi-purpose meter. Multimeter is composed of magneto-electric ammeter (meter head), measuring circuit and selector switch. A variety of electrical parameters can be measured conveniently through the transformation of selector switch. The main basis of circuit calculation is closed circuit Ohm's law. There are many kinds of multimeters, which should be selected according to different requirements.
Common multimeters can measure DC current, DC voltage, AC voltage and resistance. Some multimeters can also measure capacitance, inductance, power, transistor common emitter DC amplification factor hFE, etc.
A multimeter can be used to measure not only the resistance of the object being measured, but also the AC/DC voltage. Even some multimeters can also measure the main parameters of the transistor and capacitor capacity. Fully proficient in the use of multimeter is one of the basic skills of electronic technology. Common multimeters include pointer multimeters and digital multimeters. Pointer type multipurpose meter is a multifunctional measuring instrument with the head as the core component, and the measured value is read by the pointer of the head. The measurement value of digital multimeter is directly displayed in digital form by LCD screen, which is easy to read. Some of them also have voice prompt function. Multimeter is a common meter head, set voltmeter, ammeter and ohm meter in one instrument.