| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To directly detect water infiltrating into an aluminum tube without a worker needing to go to the spot and to dispense with a large-scale facility for measurement. <P>SOLUTION: A plurality of first optical branching devices 3 are provided spaced at intermediate parts of one conductor 2 of an OPGW 1 to branch detecting optical fibers 4 from the conductor 2. The tip faces 4a of the detecting optical fibers 4 are arranged in water observation positions 5, and an optical pulse tester 6 is connected to one end 2a of the conductor 2 to irradiate measuring light 7. The position and intensity of reflected light 8 from the tip face 4a of each detecting optical fiber 4 is observed by the optical pulse tester 6, and water in the corresponding observation position 5 is detected based on a decrease in the intensity of the reflected light 8. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
