Analog vs Digital Multimeter
万用表或多年份是电子产品中使用的测量仪器，旨在执行几种测量仪器的任务。可以使用公共万用表中的不同选项进行电压，电流和电阻测量；因此，它也称为VOM（VOM欧姆表）。在更昂贵和高级的模型中，也可以测量电容和电感，并可用于检测半导体元件（如晶体管和二极管）的引脚。
More about Analog Multimeter
Analog Multimeter is the older type of the two multimeters, and it is actually an ammeter. Its operation is based on a spring loaded moving coil mechanism positioned inside a magnet. When a current flows through the coil, interaction between the induced magnetic field in the coil and the fixed magnet create a force to move the coil. The needle connected to the coil moves proportional to the force produced, where the force is proportional to the current flowing through the coil. The moving needle points to the numbers marked on a dial, indicating the amount of current passing through the coil.
To measure voltage and resistance, the internal circuit is attached to additional circuits such that current through the coil represent the voltage or the resistance. This additional circuitry also gives multimeter the ability to operate on different value ranges. For example, with a multimeter it is possible to measure 20mV and 200V, but the scale has to be set accordingly.
The output (display) of the analog multimeter is a real time continuous output, where theoretically the needle indicates the value at that instant. Therefore, analog multimeters are preferred still by some professionals due to its real time response which is important when measuring capacitor or inductor circuits. Disadvantages of the analog meters are the parallax error they cause in the readings and the delay in response due to the inertia of the needle and the mechanism. This inertia become advantageous when there is noise present in the measurement; that is the needle would not move for small changes when the voltage or current is measured.
必须提供模拟多项式，以测量电阻。通常使用AAA电池。根据当时电池的输出电压（随时间降低而不是1.5 V），必须手动调整电阻刻度为零。
More About Digital Multimeter (DMM)
数字万用表, which is the newer type of the two multimeters, is completely electronic in operation, and no mechanical components are involved in the measurements. The whole operation of the device is based on electronic components.
In contrast to the operation of the analog multimeter, digital multimeter uses voltage to detect the input signal. All the other measurements such as current and resistance are derived from the voltage across the test leads.
Digital multimeters obtain several samples of the signal during a short period of time and average the signals to provide better accuracy. The analog signal is converted into a digital signal by the analog to digital converter, which is the most important component of the multimeter circuit, inside the multimeter. To improve precision further, most DMM models use a method called successive approximation register (SAR) in the analog to digital conversion step.
Digital multimeters display a numerical value as the output which has a higher accuracy than the analog multimeters. Also, advanced digital multimeters offer automatic ranging features so that the user do not have to select the range of the measurement manually. Additionally, this becomes a safety feature too. Since no moving parts are inside, the digital multimeters are unaffected by shocks such as the impact with a solid surface.
模拟和数字万用表有什么区别？
•模拟数量表将输出作为对指针的读数的读数，而数字万用表输出则以数值形式显示在LCD上。
• Analog multimeters give a continuous output and carry a greater uncertainty in the measurement (about 3%), while digital multimeter measurements have a far less uncertainty (about 0.5% or less). Digital multimeters are more accurate than analog multimeters.
• Digital multimeters have a better range of measurements than analog multimeters.
• Digital multimeters offer additional features such as capacitance, temperature, frequency, sound level measurements and detection of semiconductor device pins (transistor / diode).
•必须手动校准模拟多项式，而大多数数字数组在每次测量之前都会自动校准。
•必须为特定的测量范围设置模拟多项式，而有些必须具有数字多项式具有自动范围功能。
•模拟多项式需要练习才能进行良好的测量，而数字多组也可以由未经训练的人进行操作。
• Analog multimeters are less costly while digital multimeters are expensive.
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