| 摘要 |
PROBLEM TO BE SOLVED: To provide an installation structure of a length meter capable of adjusting an axial position of laser light of the length meter without opening a vacuum container, and adjusting the axial position of the laser light through accurate and simple operation even in the case where a length meter in which an input plane of laser light crosses an output plane, is used.SOLUTION: A vacuum container B for housing a length meter therein is provided separately from a vacuum container A for installing an object to be measured therein. In a side part of the vacuum container A, an installation base 5 is installed while being integrally fitted to the container A or a surface plate supporting a portion to be measured. On the installation base 5, the vacuum container B is installed while being disposed in such a manner that a sidewall of the container B is overlapped to a sidewall A1 of the vacuum container A with a side part plate material interposed therebetween. Laser light is made incident into the vacuum container A from a length meter 1 housed within the vacuum container B through laser light axis holes provided at corresponding positions of both the vacuum containers A and B, and laser light made incident and reflected in the object to be measured is made incident into the length meter 1. |
