The most comprehensive multimeter knowledge sharing
The multimeter is one of the most commonly used measuring instruments for electronics enthusiasts. It is an instrument that integrates a variety of commonly used electrical measurement functions. Nowadays, many multimeters are developing in the direction of intelligence. There are many types and functions of multimeters on the market. How to choose a multimeter that suits you? How to use the multimeter? The multimeter knowledge you care about is introduced in detail below.
1. What is a multimeter
Multimeters, also known as multimeters, multimeters, three-meters, multimeters, etc., are indispensable measuring instruments in power electronics and other departments. Generally, the main purpose is to measure voltage, current and resistance. Multimeters are divided into pointer multimeters and digital multimeters according to the display method. It is a multi-functional and multi-range measuring instrument. Generally, the multimeter can measure DC current, DC voltage, AC current, AC voltage, resistance and audio level, etc., and some can also measure AC current, capacitance, inductance and semiconductor. some parameters.
2. The role of the multimeter
Basic functions: three basic test items of voltage, current and resistance
Expand air energy: measure capacitance, inductance, frequency, duty cycle, temperature, and triode magnification
3. Classification and principle of multimeter
Common multimeters include pointer multimeters and digital multimeters. Pointer multimeter is a multifunctional measuring instrument with the head as the core component, and the measured value is read by the pointer on the head. The measured value of the digital multimeter is directly displayed in the form of numbers by the liquid crystal display, which is easy to read, and some also have a voice prompt function. A multimeter is a meter that combines a voltmeter, an ammeter and an ohmmeter in one meter.
Multimeter principle
The basic principle of the multimeter is to use a sensitive magnetoelectric DC ammeter (microampere meter) as the meter head. When a small current passes through the meter, there will be a current indication. However, the meter head cannot pass a large current, so some resistors must be connected in parallel or in series on the meter head to shunt or lower the voltage, so as to measure the current, voltage and resistance in the circuit.
4. Multimeter purchase skills
1. Display digits and accuracy of the multimeter
Display digits and accuracy are the most basic and important indicators of a multimeter. Generally speaking, the higher the number of digits displayed by the multimeter, the higher the accuracy, and vice versa.
2. The measurement method and AC frequency response of the multimeter
The measurement method of the multimeter is mainly for the measurement of AC signals. With the change of the frequency of the AC signal, various frequency responses appear, which affect the measurement of the multimeter. There are generally two methods for multimeters to measure AC signals: average value and true RMS measurement.
3. Function and measuring range
Different multimeters, their manufacturers will design different functional measurement ranges. Ordinary multimeters can test AC and DC voltage, current, resistance, on-off, etc., but some multimeters do not have a current function in order to reduce costs.
4. Measuring Stability and Protection
A good multimeter has good self-protection. For example, when some multimeters are inserted into the wrong test lead line, it will automatically generate a buzzer alarm... When purchasing a multimeter, don't blindly covet cheap, but be practical and easy to use.
