Background introduction

The study of the fluorescence temperature sensor has been carried out for more than thirty years, and has gradually developed into the commercial field. And the optical fiber sensor used in pure optical principle, anti electromagnetic interference, high voltage insulation, small size, stable reliability, sensitivity and long life etc. it has incomparable advantages, gradually commercial use in monitoring, high-voltage electrical equipment industrial heat treatment equipment, microwave and magnetic / Petrochemical / coal explosion-proof industrial environment, aviation / / Research ship.

The fluorescence has no direction, so as to collect fluorescence generally uses the large core diameter mostly mode fiber, so need more fluorescent substances caused by the rise in the cost of the double clad fiber can not only the laser coupling has good beam quality into the core conduction to the fluorescent substance, at the same time using fluorescence with large receiving area of high light collection the efficiency of double clad fiber inner cladding to collect the fluorescent material, which can greatly enhance the light collection efficiency of fluorescence optical fiber temperature measurement.

Two, working principle

The basic principle of optical fiber fluorescence temperature measurement system as shown below, the periodic pulse square wave pulse semiconductor laser fluorescence probe, in part through the coupling lens into double clad fiber and was spread to the optical fiber end face; fluorescent material through excitation emission fluorescence by double clad fiber inner cladding is received, the receiving the fluorescence through the coupler into a photoelectric detector, detector by measuring fluorescence lifetime, so as to obtain the temperature probe.