Research Of Optical Fiber In Seepage Experimental Techniques

With the development of the optical fiber sensing technology, optical fiber sen-ors are widely used in the temperature and pressure sensing field. Compared with theprevious all kinds of sensors, fiber optic sensor has high sensitivity, small volume,simple structure, good electrical insulation, electromagnetic interference resistance,corrosion resistance, explosion-proof, etc. Since the advent of fiber sensor, it got theattention of the scientific and research institutions around the world in seepage resear-ch.In this paper, we use PROFIBUS technology to build a128-channel data acqu-sition system, and then we use the system to design and complete two seepage exp-riments. The system is able to take advantage of real-time and accurate multi-pointsimultaneous measurements and has a higher resolution rate and measurement accu-racy. Also,a novel fiber sensor based extrinsic Fabry-Perot interferometer is demons-trated for the accurate measurement of the liquid surface. The method is more safeand effective comparing with traditional electrical methods. Experimental resultsshow that the sensor can precisely measure the liquid surface and the relative error isonly1.48%.The main content of this paper is as follows:The first chapter summarizes the basic sensing principle of fiber EFPI sensor.Also, we introduce some research backgrounds and the domestic and foreign develop-ments, finally we summarize the content of this research.The second chapter presents the PROFIBUS data acquisition system. The systemis described in detail from the architecture and system design, and finally we introdu-ce the technical parameters and functions of the acquisition system.The third chapter is described in detail, including the capillary resistance andcore permeability test, which are all based on128-channel data acquisition system.The fourth Chapter presents a novel fiber sensor based extrinsic Fabry-Perot int-erferometer for the accurate measurement of the liquid surface, including the principl-es of analysis, sensor design and experimental verification.The fifth chapter summarizes the main research work of this paper, and discussesthe future research direction of this project.