Optical Fiber Temperature Measurement System Based On Fluorescence Intensity

Temperature measurement is of great importance in our daily life as well as in the fields of production,research and engineering.There are different kinds of thermometric instruments,which is chosen according to different environment and the requirements of measurement range and accuracy.Optical fiber temperature sensors,which have the advantages of anti-electric magnetic field interface,small size,long service life and anti-corrosion is one of the most popular optical fiber temperature sensors used in the electric environment.Fluorescence optical fiber temperature measurement system is flexible in fluorescent material selection and is one of the most popular research direction in optical fiber temperature sensors.A low-cost temperature measurement system with multichannel and heat-resistance which can be used in electric system was described in this paper.Firstly,the overall optical structure is described.A reflection-type measurement system is used to measure fluorescence intensity by which temperature is calculated.We use a multimode 1×2 optical fiber,the incidence end of the fiber is coupled with pump light and the exit end is coupled with the probe and the detecting end is used for fluorescence collection.Ruby and ferrule are used to construct our low-cost heat-resisting fiber probe,and it is tested through experiment that the fluorescence intensity of ruby and temperature response have a linear relationship in 30??130?.We selected 405nm LD as our excitation light generator and we achieved ideal coupling result through direct coupling.Secondly,we designed,simulated and tested fluorescence detecting circuit.Optical filter HB630 is used to remove excitation light and PIN silicon photodiode is used for detection.We consider the output of PD as weak current,which is amplified and converted to voltage signal by a dual-stage amplifier.We used ADC module in MSP430 for sampling and the data is uploaded through serial port communication after which a way of multichannel measurement is given.Finally,we use Lab VIEW for reading and displaying temperature results,and discussed temperature calculation and resolution improvement in the end of chapter three.A whole temperature measurement system is described by this article,and the results given proved the feasibility and validity of this fluorescence-intensity based thermometric system.