| 摘要 |
PURPOSE:To measure accurately the shape of an excavated cavity or the like without moving the whole of a measuring machine by providing an elevating means of a rod and providing a length measuring sensor and a rotation driving means of the length measuring sensor at the front end part. CONSTITUTION:When a sensor 15 reaches a depth position DP where the shape of an excavated cavity or the like should be measured, a rod 10 is stopped from being fed out in the direction of an arrow A by a jack 9, and a motor 6 is rotated and driven to rotate a table 5a of a turntable 5 in a certain angular speed in the direction of an arrow C or D together with an up/down jack 9. The rod 10 grasped by the jack 9 is rotated also in the same angular speed of the jack 9, and the ultrasonic sensor 15 is rotated also. Though an excavated cavity 19 is filled up with muddy water and muddy water is flowed by the rotation of the rod 10 or the like, sensors 13 and 15 are held surely in muddy water without rocking because they are supported by the rod 10. |
