The Research On Distributed Fiber Detecting System Of Tanks' Parameters

Optical fiber sensing technique is one of the hot-spot subjects in the studying field ofphotoeletricity test technology today. The detection system using this novel structure sensortechnology can be called "all optics" in measuring field .It is especially applicable in theinflammable and explosive environment. High precision and good essential safe performance areneeded in the measurement of oil tank multiparameter such as liquid level and temperature.According to measurement requirement in the special operating condition, the author of thispaper presents the oil tank parameters detection system based on the distributed optical fibersensing technique. Compared with the traditional measurement system, it is of safety in essenceand more adaptable to inflammable and explosive situation because of non-electricity onmeasuring spots. Applying distributed fiber measurement principles, we can achieve multi-pointmeasurements in the same optical fiber, and this method is suitable for sensing in large-scalemeasurement field and large information content transmission. Whether the feasibility of thetechnology or the blue future of the application, it is very important to improve the precision andfeasibility of national oil tank parameters measuring system.In this paper, the author introduces in detail the principle and the features of the optical fibersensing technique, and highlights the principle and practical application of optical fiber gratingsensing, which is most rapidly developed nowadays in the field of optical fiber sensing. Then,the author deep discusses the principles of distributed optical fiber sensing networks and signaldemodulation. The author discusses several popular filed bus technology today. According to itscharacteristics and requirement, the system can be divided by the architecture into the dataacquisition layer, monitoring layer and administration layer, and the network is composed ofEthernet which is the upper network and RS-485 network which is the lower network. Thehardware and software design about the system is elaborated at last.In this paper, the oil tanks distributed detecting system consists of the optical fiber liquidlevel meter, optical fiber grating temperature sensor, optical fiber superhigh alarm and opticalfiber fire alarm, which are developed through the optical fiber sensing technology. This systemenables the measuring process to avoid completely the electrical signals so as to meet theessential safety requirement.In the whole system, functions of automatic detection, display, alarm, and print are realized,which is the foundation of the modern management of oil tank sections. Characterized with thecommunication between people and machine more concise, structure expanded more flexibleand high reliability, the system contains excellent property in current use and engineerpopularization.