| 摘要 |
PURPOSE:To measure the center of an access hole lid against the origin of the device and exactly place the lid axis in the center. CONSTITUTION:A base plate 28 having a coupling frame 24 capable of coupling with a metal hook 23 in the upper surface of an access hole lid 7 is provided. The main frame 17 is put on the base plate 28 and supported rotation free. On the main frame 17, an ultrasonic probe 39 is placed for detecting the outer end position of boss shape level difference part 38 fixed on the back side of the lid 7. On one side of the main frame 17, an arm 34 is supported free of standing and lying. At the tip of the arm 34, a scriber 35, a scale plate 36 and a camera 37 are placed. |
