介绍一种基于激光发射器和二维位置敏感探测器PSD的双光束激光对中仪的组成结构 ,给出对中仪 3种测量原理 ,并由计算机计算测量结果。 The composition of a dual-beam laser centering instrument based on laser transmitter and two-dimensional position-sensitive detector PSD is introduced. Three measuring principles of the centering instrument are given, and the measurement results are calculated by the computer.