| 摘要 |
PURPOSE:to enable centering of a long structure with high precision, by a method wherein the long structure is secured and erected in a vertical shaft in a manner that the axis of the long structure is located parallel to that of a collimation pipe, a vertical collimating device is installed, and centering is effected as a target plate is watched. CONSTITUTION:A target plate 17 is attached to the upper end of a collimation pipe 1 through a slide device 18, and is positioned so that the coordinate center of the target plate 17 coincides with the axis of the pipe 1. A vertical collimating device 21 is located above the target plate 17, and a vertical line of collimation is brought into concidence with the coordinate center of the target plate 17. A target plate 2 in the collimation pipe 1 is watched by means of the vertical collimating device 21, and a long structure 6 is centered in a way that the vertical line of collimation coincides with the coordinate center of the target plate 2. This enables centering of the long structure with high precision, and permits a work to be easily and simply performed from a ground. |
