| 摘要 |
A building being erected is aligned with the vertical by projecting a main laser beam horizontally and splitting it into a vertically reflected test beam that is received on the building and used to ascertain proper alignment thereof with the vertical and a horizontally reflected adjustment beam that is received at a detector having an array of receptors around a central receptor. So long as the adjustment beam is received at the central receptor, the proper vertical positioning of the test beam is insured. If the adjustment beam moves off the center receptor, however, a positioning motor connected to the projector is actuated to reposition the main beam and the splitter to as to realign the adjustment beam with the central receptor and simultaneously realign the test beam with the vertical. |
