How to choose a multimeter? How to choose a multimeter
A multimeter consists of three main parts: the meter head, the measurement circuit and the changeover switch. Multimeter is the most basic tool in the field of electronic testing and a widely used testing instrument. Multimeter is also known as multi-meter, triple meter (A, V, Ω that is, current, voltage, resistance, three), multiplexing meter, multimeter, multimeter is divided into pointer multimeter and digital multimeter, there is also an oscilloscope with oscilloscope function of the oscilloscope multimeter, is a kind of multifunctional, multi-range measurement instrument.
General multimeter can measure DC current, DC voltage, AC voltage, resistance and audio level, etc. Some can also measure AC current, capacitance, inductance, temperature and semiconductor (diode, transistor) of some parameters. Digital multimeter has become the mainstream, has replaced the analogue meter. Compared with analogue meters, digital meters have high sensitivity, high accuracy, clear display, strong overload capacity, easy to carry, and more convenient and simple to use.
The DC current file of the multimeter is a multi-range DC voltmeter. The head of the multimeter can be connected in parallel with a closed-circuit voltage divider resistor to expand its voltage range. The DC voltage range of the multimeter is a multi-range DC voltmeter. The voltage range of the multimeter can be enlarged by connecting a voltage divider resistor in series with the head of the meter. Different voltage divider resistors have different ranges. The head of the multimeter is a magneto-electric measuring mechanism, which can only pass DC, and uses a diode to change AC to DC, thus realising the measurement of AC power.
Like most instruments and meters, multimeter itself has measurement stability, the accuracy of its measurement results is related to its use time, environmental temperature and humidity. If the stability of the multimeter is poor, after a period of time, the multimeter will sometimes contradict itself with inconsistent measurement results. Therefore, some manufacturers pay great attention to this aspect of the problem: such as the United States Fluke company in the recent sales of new products in the promise of lifelong traceable calibration and warranty.
Most of the maintenance engineers use the multimeter, the most worried about the poor protection of the multimeter, inadvertently in the pen line plugged into the wrong or test file error, resulting in unnecessary damage to the multimeter, affecting the work. Therefore, the security of the multimeter is very important, some good multimeter self-protection is very good, like some multimeter inserted into the wrong pen line, will automatically generate a beeping alarm so that the purchase of the multimeter, do not blindly cheap, to be practical, good to use it.
