Optical fiber type temperature distribution measuring apparatus

An optical fiber type temperature distribution measuring apparatus, wherein a light pulse is transmitted into an optical fiber installed in an object to be measured, and a temperature distribution value representing a series of segment average temperatures of the optical fiber is measured on the basis of the intensity of Raman back scattering light and a time until the Raman back scattering light returns, said optical fiber type temperature distribution measuring apparatus comprising:

• light pulse oscillating means for oscillating the light pulse having a predetermined pulse width;
• selective switching means provided at a light pulse transmitting side of the optical fiber and including a plurality of fiber length adjusting optical fibers respectively having different lengths so that their mutual phase difference is smaller than a distance resolution in temperature measurement, said selective switching means selectively connecting the plurality of fiber length adjusting optical fibers to the optical fiber to form a plurality of detection routes having different lengths;
• and
• calculating means for calculating a plurality of temperature distribution measurement values respectively corresponding to the plurality of detection routes, and for calculating a temperature distribution value representing a series of temperature values of respective subsegments of the optical fiber, a plurality of the subsegments corresponding to a segment which in turn corresponds to the distance resolution.