Narrow And Small Curved Surface Level Gap Optical Fiber Bragg Grating Measurement System Development

In recent years, the optical fiber sensor ,as one kind of new component, is playing the vital role in many domain.The optical fiber Bragg grating sensors developed rapidly as one kind of new optical fiber sensor in recent twenty years, because it had many advantages compared with the traditional electromachanical transducer, such as: The essence guards against explosions, the anti-electromagnetic interference, the anti-radiation, thermostablly, the small volume, the light weight, nimble convenience, and so on, and thus it obtained the widespread application.This thesis used the strain characteristic of the optical fiber Bragg grating, designed and manufactured a set of optical fiber Bragg grating measurement system in the narrow and small curved surface level gap.The main research works and the achievements divide into 3 parts: Senser development, demodulation system development and examination demarcation installment development.1st The development of senser.In view of the narrow and small spatial gap survey,the senser is the most essential part, we developed successfully the double optical fiber Bragg grating ultra thin structure senser through the massive experiments. The double optical fiber Bragg grating ultra thin structure senser had used a special structure shrapnel, and had buried two different Bragg wave length diffraction grating in sheet steel.The sensor sheet steel structure is the key to transform the gap of the curved surface to the optical fiber Bragg grating axial strain .the sheet steel material requires appropriate thickness,good elasticity and high intensity .We had solved the question of temperature and the demodulation system inaccuracy ,and also had increased the sensitivity of sensors by adopting double optical fiber Bragg grating structure.2nd, The development of demodulation system.In view of special request for the project, this paper had researched the optical fiber Bragg grating demodulation system from two aspects of the hardware and the software. According to the application need, from the aspect of the software ,we had adopted the modular design as well as the friendly man-machine interaction contact surface, and had enabled the demodulation system to have the following function: 1st, the function of real-time wave length demonstration, real-time wavelength separation demonstration, real-time gap survey demonstration; 2nd, the function of data storage; 3rd, the function of sensor demarcation ;4th, the function of different radius curved surface survey; 5th, the function of curved surface gap computation; 6th, the function of playbacking data.3rd, The development of examinating and demarcating equipment.The sensor we developed, was used for special occasion, and had not the mature examination equipment, therefore,how to examinate and demarcate the sensor is also an important work.We had designed carefully the examinating and demarcating equipment through the massive experiment research.We had researched the feasibility of optical fiber Bragg grating measurement system for 2 parameters in the narrow and small curved surface level gap on the above-state foundation ,and had obtained the nice results.