Optical Fiber Temperature Detection System Based On DSP And CPLD

The distributional optical fiber temperature examination technology is in the temperature examination aspect emerging one kind of examination technology, The distributional optical fiber temperature measurement comes from20th century mid and late parts by the optical fiber communication development. As one kind of young examination technology, the distributional optical fiber temperature measurement passed through the short several dozens year development, the various countries has all made the very big progress in this aspect. Under the attention of the relevant departments of the State, universities and research institutions in this area of research has yielded the results, some products have reached the international advanced level.The distributional optical fiber temperature measurement technology compared to the traditional sensor temperature measurement in examination aspects and so on scope does well, the optical fiber sensing technology has traditional sensing technology no unique merit. The optical fiber sensing technology has the non-contact, the high accuracy, the sensitivity high, the speed quick and so on the characteristics, it solved the traditional sensor to monitor the place in the high pressure easily by the electric breakdown and easily the electromagnetic interference. The traditional sensor temperature measurement technology can only achieve temperature points of measurement, distributed optical fiber temperature sensor can realize the long distance, large scope, continuous temperature detection. Because of distributed optical fiber temperature sensor technology in temperature in the inspection of the advantages. This article through to the freezing temperature detection of borehole Wells cut the application to introduce and analyze distributed optical fiber temperature measurement system, through to the freezing temperature testing to the shaft of the frozen wall temperature field testing.Distributed optical fiber temperature measurement system is based on Raman scattering theory as the theoretical basis, The system through the principle of Raman scattering light reflection time domain analysis and study of the principle, established the model of the Raman scattering, After using the Raman scattering sensing temperature information collection, and concludes that the unit time light receptors receives the light power. The system was discussed space positioning principle and the spatial resolution and temperature resolution and improvement measure. Discussion back to improve the signal-to-noise ratio of the signal, the method of this system mainly according to sampling integral method to improve the signal-to-noise ratio of the system. This paper introduces the system of each module function and system software design process, design the DSP module, CPLD module, AD modulus conversion module, and other modules, Given the overall design software, DSP software flow chart and CPLD software flow chartThrough to the freezing temperature detection test wellbore analysis, we can conclude that distributed optical fiber temperature measurement system for measuring temperature environment to take distributed continuous temperature measurement, by the formation of the temperature is continuous, large scope. Than traditional sensing technology cost is lower, the system even more simple, therefore, distributed optical fiber temperature sensor technology has great application space and development prospects.