Temperature-measuring method and distributed optical fiber temperature sensor

摘要

A temperature-measuring method comprises inputing laser pulses into an optical fiber to be measured and measuring temperature distribution in the fiber from the ratio of the amplitudes and the delay time of Stokes light and anti-Stokes light contained in the return beam from the optical fiber, wherein the temperature distribution is measured by using equations: ##EQU1## where T(x) is temperature to be measured, &THgr; is the reference temperature, R' (T) is the relative ratio of amplitude at the measuring point, R' (&THgr;) is the relative ratio of amplitude at the reference temperature point, k is Boltzmann's constant, h is Planck's constant, c is velocity of light, &ngr; is Raman shift, &agr; is distance, wherein the attenuation difference &agr; is represented by a function &agr;{T(&tgr;)} dependent on temperature T(&tgr; ) at the measuring point &tgr;, and the exponential function in which the exponential part is represented by a value obtained by integrating the function &agr;{T(&tgr;)} with the variation d&tgr; in distance, is employed as a correction factor.