The Design Of Raman-type Distributed Optical Fiber Temperature Sensor System

Distributed optical-fiber temperature sensor(DOFTS)method have been widely used to obtain the temperature profile in industries,optoelectronics,and power cables and fire detection.Different from conventional temperature measurements,DOFTS has the advantages of continuous temperature measurement,real-time monitoring,remote controlling,electrical insulation,anti-electromagnetic interference and small volume.Rayleigh,Brillouin and Raman are the main types of DOFTS.The most mature Raman-type DOFTS is excessively researched and implemented in many projects.Embedded technology has been emerged in mobile phones,industrial control systems and automobiles etc.This special technology possess many advantages such as high real-time,simple operation and small volume.In this paper,a novel distributed optical-fiber thermometer and embedded technology were integrated.Real-time monitoring,distributed measurement and mobility were recorded by using the sensor.The investigation was accomplished on thorough understanding of basic theory application,hardware and software designs,and finally experimental measurements.The analyzed results and investigation were consistent with the development trend of intelligent manufacturing and summarized as follow.(?)The research progress and application of Raman-type DOFTS were systematically described and analyzed.(?)The OTDR,the optical scattering principle,the demodulation algorithm and the measure index accompanied by the comparison of different scattering DOFTS and different demodulation algorithm were studied and analyzed.(?)A distributed optical-fiber temperature sensing system based on backward Raman scattering and anti-Stokes/Stokes intensity ratio was designed.In order to find out appropriate technical parameters,the semiconductor laser,photoelectric conversion module,data acquisition and processing module were designed and investigated.(?)The special hardware platform were comprised of software programs with different functions,including laser control program,FPGA/DSP/ARM's inter-core communication,synchronization control program,high-speed acquisition and high-speed accumulator program on FPGA.(?)The calibration experiment and the measurement experiment were carried out.