Design Of FBG Temperature Sensitive Sensor And The Software Of Its Monitoring System

Fiber Bragg Grating(Fiber Bragg Grating,FBG)is a kind of wavelength modulated optical fiber sensor,has the advantages of high sensitivity,small size,simple structure,good linearity,wide application in the field of sensor.Temperature sensing is one of the most important and direct applications of fiber grating sensors.With the development of fiber gratings,the study of their temperature characteristics has gradually become a hot spot.However,the conventional packaging fiber Bragg grating has low temperature sensitivity and is not suitable for use in some high-precision conditions.Firstly,based on the analysis of the FBG temperature response mechanism,two high sensitivity FBG temperature sensors based on metal cladding and metal substrate packaging are designed.Metal packaging is a typical and effective method for temperature sensitivity enhancement of FBG sensors.In accordance with the metal substrate packaging method,the fiber grating is bonded to the stainless steel work piece surface with high thermal expansion coefficient through proper process.Based on the surface preparation of fiber grating and magnetron sputtering of copper layer,the copper grating layer,copper layer and copper tin layer with different thickness were respectively plated on the fiber grating.Secondly,the sensitivity,repeatability and stability of the two sensors are tested respectively.The experimental results show that the sensitivity of the metal substrate 3 times FBG temperature sensor can achieve the bare grating temperature sensor FBG,can increase the sensitivity of bare grating effectively,the upstream and downstream temperature experiment proves its good repeatability.The FBG temperature sensor packaged with metal coating can reach 2 times more than the bare grating FBG temperature sensor,and the test results show that the wavelength drift is not large,and it has good stability.Finally,for the convenience of real-time online reflect the actual temperature of the object to be tested,and realize the storage and prediction analysis of monitoring data,using the C++ language to carry out include data acquisition,data processing,real-time display,data storage,software design of alarm functions.Including TCP/IP communication,data acquisition,data processing,real-time data display,spectral data display and storage,historical data query and alarm module.The sensitization mode designed in this subject can effectively improve the sensitivity of FBG temperature sensor and meet the requirements of high precision test field.At the same time,the upper computer software can realize the prediction and analysis of the field temperature,which is convenient for practical engineering applications.In order to expand and deepen the use of FBG temperature sensors and to explore the potential applications of FBG temperature sensors,the method and experimental basis are laid out.