采用激光扫描与CCD探测系统的大型工件平行度垂直度测量仪，以稳定的激光束为测量基线，配以回转轴系，旋转五棱镜扫描出互相平行或垂直的基准平面，将其于大型工件的各个面进行比较。在大型工件的安装或测量时，可用本仪器测量面向间的平行度或垂直度。(The stable laser beam is taken as the measuring baseline, and the rotary axis system is rotated together. The five prism is rotated to scan the parallel or vertical datum plane. In the installation or measurement of large workpieces, the instrument can be used to measure the degree of parallelism or perpendicularity to the inter - face.)