Research FBG Temperature Measurement System Based On FFP-TF Demodulation Technique

In recent years, Fiber Bragg Grating (FBG) sensor,with many advantages, has become one of the hot research on sensing field of fiber grating and has a extremely considerable application prospect in the fields of petrochemical chemical industry, marine exploration, aerospace, coal mining and other fields. To complete the monitoring of the temperature of the FBG sensing device, demodulation technology is one of the important links. Fiber Fabry-Perot Tunable Filter (FFP-TF) demodulation method has the advantages of wide tuning range, high sensitivity etc., and can directly output FBG wavelength corresponding photolysis signals. So it can be widely applied to the measurement of multipoint scanning system.Therefore, the experimental research and exploration of FBG sensor measurement system based on FFP-TF demodulation technology, which designed in this paper, work from the following several aspects:1. Analyzed FBG sensing principle, coupled-mode theory, demodulation technology and the characteristics of reflection spectrum. Established the FBG temperature sensing model.2. Designed FBG temperature sensor based on FFP-TF demodulation technology, including light path transmission module, circuit demodulation module and Lab VIEW program and interface.3. Compared the performance test of two acquisition methods of data acquisition card which based on STM32and NI USB6009. Choosed NI USB6009data acquisition card system as the main experimental method in this paper.4. In the experimental part, used FBG temperature sensor to monitor the different environment temperatures. Analyzed the data from experiment and concluded the correspondence between outside temperature and FBG wavelength.The experimental results show that the temperature sensing device has good stability. The measured temperature and external temperature is consistent and error of measurement svstem is within土0.2℃.