RADIATION THERMOMETER HAVING LIGHT RECEIVING LOSS COMPENSATION FUNCTION AND TEMPERATURE MEASURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To compensate for the transmission loss of an optical fiber in a service condition, and thereby provide a transmission loss compensation function capable of continuous measurements over a long time. SOLUTION: A partially reflective coating 2a is preliminarily applied to the reverse side of a condenser lens 2 and the preset light quantity P of pulse light having wavelength reflected due to the coating 2a at the time of using a radiation thermometer is inputted from the outside via an optical fiber for introduction to the condenser lens 2. As a result, light reflected from the reverse side of the condenser lens 2 sustains a transmission loss corresponding to back- and-forth across the optical fiber, and is measured after addition to ordinary measurement light. According to this construction, the light quantityΔS of reflected light after sustaining the transmission loss corresponding to the back- and-forth of pulse light can be found from the changes S1 and S2 of the light receiving quantity due to the existence and non-existence of the pulse light. The transmission factor Tr of the optical fiber can be calculated from the value ofΔS for making compensation for the transmission loss.