| 摘要 |
PURPOSE:To achieve a highly accurate and simple monitoring of a disturbance condition caused in an optical fiber line by providing a sensor fiber connected to the optical fiber line. CONSTITUTION:A disturbance condition such as flooding, rise in humidity and temperature change occurs, a bending loss is generated locally with the action of fiber sensors 1, 2 and 3 connected to an optical fiber line and a step (point of discontinuity) appears in a waveform of a back scattered light. A size of and a hourly change in the step at this point of discontinuity are detected. This enables judgement of the type of the disturbance, the life of the line. |
