三坐标和影像仪有什么样的区别 What are the Differences Between Coordinate Measuring Machines (CMMs) and Vision Measuring Instruments?

　　​随着制造技术和标准要求的发展，传统的测量工具如游标卡尺等已经越来越难以满足测量需求。高精密的测量仪器在越来越多制造企业上得到应用。
        With the advancement of manufacturing technologies and the upgrading of standard requirements, traditional measuring tools such as vernier calipers have become increasingly inadequate to meet measurement demands. High-precision measuring instruments are being adopted by an increasing number of manufacturing enterprises.

        在二维测量角度上，有影像测量仪，结合了光学投影和计算机技术而成，在CCD数位影像的基础上，依托于计算机屏幕测量技术和空间几何运算的强大软件能力而产生的。而如果从空间三维的角度来说，那就是三坐标测量仪。通过对空间坐标数值的采集，拟合成测量元素，通过算法计算出位置公差等数据。
        For 2D measurement, video measuring machines (VMM) are employed. These instruments integrate optical projection and computer technology, developed on the basis of CCD digital imaging, supported by computer screen measurement technology and powerful software for spatial geometric computation.
        For 3D spatial measurement, coordinate measuring machines (CMM) are used. By acquiring spatial coordinate values and fitting them into geometric features, position tolerances and other data are calculated through algorithms.

1.机器原理不同
影像测量由CCD、光栅尺等部件组成的高精度光学测量仪器，基于机器视觉技术及微米精确控制完成测量过程。测量中将通过USB及RS232数据线传输到电脑的数据采集卡中，将光信号转化为电信号，之后由影像测量仪软件在电脑显示器上成像，由操作员用鼠标在电脑上进行快速的测量。
三坐标测量机：通过三个相互垂直的导轨上移动的方式，以接触或非接触等方式传送讯号，三个轴的位移测量系统经数据处理器计算出工件的各点坐标(X、Y、Z)及各项功能测量的仪器。
1.Different Working Principles
Video measuring is a high-precision optical measuring instrument composed of CCD, grating scales and other components. It performs measurements based on machine vision technology and micron-level precision control. During measurement, signals are transmitted to the data acquisition card in the computer via USB and RS232 cables, converting optical signals into electrical signals. The video measuring software then generates an image on the computer monitor, allowing the operator to perform rapid measurements using a mouse.
Coordinate Measuring Machine (CMM): An instrument that moves along three mutually perpendicular guide rails, transmits signals via contact or non-contact methods, and calculates the coordinates (X, Y, Z) of each point on the workpiece as well as various functional measurements through a data processor based on the displacement measuring systems of the three axes.

2.作用不同
二次元测量仪主要应用在二维平面测量领域，如一些机械、电子、五金等行业，有测头的可以测量一些简单形位公差，如平面度，垂直度等。
三次元测量仪以三维测量为主，可以测量形状复杂的机械零件的尺寸，形位公差和自由曲面等。
2.Different Functions
The 2D video measuring machine is mainly applied in 2D planar measurement, such as in machinery, electronics, hardware and other industries. Equipped with a probe, it can measure simple geometric tolerances including flatness, perpendicularity, etc.
The coordinate measuring machine (CMM) focuses on 3D measurement and can measure dimensions, geometric tolerances, and free-form surfaces of complex-shaped mechanical parts.

影像测量仪和三坐标测量仪都有其各自的适用范围，需在充分了解使用需求后再进行采购。
Both video measuring machine and coordinate measuring machine (CMM) have their respective applicable scopes. Purchasing decisions should be made only after fully understanding the actual usage requirements.