OPTICAL FIBER THERMOMETER

PURPOSE:To enable an optical fiber thermometer which processes optical signals from a temperature sensor by means of a photoelectric conversion module composed of a plurality of optical elements to obtain a stable thermometer output irrespective of the variation of the ambient temperature. CONSTITUTION:A photoelectric conversion module 13 composed of a grine lens 5, optical interference filters 6 and 8, glass block 7, and photodetector 9 and 11 converts an optical signal carrying temperature information from a fluorescent material 1 into an electric signal and an arithmetic circuit 18 obtains a temperature signal. In order to make the temperature of the module 13 constant, a temperature detecting sensor 14 and heater 15 are integrally buried in the module 13. In addition, the temperature of the module 13 is controlled so as to obtain a stable output from this thermometer irrespective of the ambient temperature by providing a temperature detecting sensor 17 on the outside of the module 13 for detecting the ambient temperature of the module 13 and sending the detected value of the sensor 17 to a temperature control circuit 16.