| 摘要 |
PROBLEM TO BE SOLVED: To attain efficient and accurate monitoring of an optical fiber automatically. SOLUTION: Measuring data obtained by measuring a monitor object optical fiber 1 with a wide optical pulse in the past are stored in advance as initial data Pa-Pc and measuring data obtained by measuring the monitor object optical fiber 1 with a narrow optical pulse in the past are stored in advance as initial data Qa-Qc. Measured data F obtained by measuring the monitor object optical fiber 1 with a wide optical pulse for monitoring are compared with the initial data Pa-Pc to check the presence of a fault and its location and in the case that there is a fault at an entrance of the monitor object optical fiber through the discrimination, the entrance part of the monitor object optical fiber 1 is measured by using a narrow optical pulse and measured data F' and the initial data Qa-Qc are compared to detect a fault location. |
