| 摘要 |
<p>PURPOSE:To measure the temperature change accurately, by constituting a temperature sensor cable by an optical fiber, whose back scatter intensity is changed by the temperature change, and an optical fiber, whose back scatter intensity is not changed, thereby offsetting the amount of change in back scatter intensity caused by disturbance other than the temperature change. CONSTITUTION:A first optical fiber 3, whose back scatter intensity is changed by the temperature change of liquid core fiber, doped silica fiber or the like, is embedded in a groove 6 in a tension member 2. A second optical fiber 4 made of silica core fiber or the like, in which change is negligible, is embedded in a groove 7 in the member 2. The member 2 is held in an outer sheath 5 made of a metal pipe made of Al and the like having excellent heat conductivity. Optical pulses are inputted to the respective fibers 3 and 4 of a temperature sensor cable obtained in this way. When temperature distribution within a specified range and local abnormality occur, the amount of change in the back scatter intensity due to the temperature change and the amount of change due to disturbance are set off against each other, and the accurate temperature measurement can be performed.</p> |
