It is caused by the lack of electricity. Three-dimensional measuring instrument mainly refers to the instrument that takes points in three-dimensional space to measure. There are also CMM, CMM and 3D CMM on the market. There are four eights in Sanfeng Sanyuan, which is caused by no electricity. The main principle is that the coordinate position of each measuring point on the measured object can be obtained by placing the measured object in the three-dimensional measuring space, and the geometric size, shape and position of the measured object can be calculated according to the spatial coordinate values of these points. The basic principle is to obtain the discrete spatial point position of the measured geometric element by detecting the cooperation between the sensor (probe) and the axial motion of the measurement space, and then through certain mathematical calculation.