| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately search a cavity generated at a periphery of an embedded tube such as a mounting tube. SOLUTION: Measuring points O are set in an underground embedded tube. Electromagnetic waves are emitted out of the tube at the respective points O. A cavity generated at a periphery of the tube is searched by observing the reflected waves. An apparatus for searching a cavity has an antenna 22 for transmitting and receiving the waves, an antenna conveyor 21 holding the antenna 22 and movable in the tube, and a controller for calculating the position and distance of the cavity according to the reflection and time of the waves and having a display unit such as a display for displaying and outputting an searched image. The conveyor 21 has a support 23 for mounting and supporting the antenna 22, a leg unit 24 for supporting the support 23 via an elastic member in contact with the inner surface of the tube, and a nonmetallic cover 25 covering the antenna 22.</p> |
