Study On Fiber Bragg Grating Sensors For Real-time Monitoring Of Reservoir Levels

In water conservancy engineering, reservoir water level measurement has been the focus of the department of hydrology and water conservancy. Accurate and effective real-time water monitoring, to prevent the happening of the accident and the effective utilization of water resources is significant. At present, in domestic many hydrological station still adopts the manual monitoring method in monitoring the water level. Existing water level monitoring sensor based on the electricity class commonly. These sensors have many limitations, for example, low security, networking hardly, and may not apply to electromagnetic interference, strong corrosion and other harsh environments. However, the emergence of fiber Bragg grating technology makes the water level monitoring technology have a new development. Due to the optical fiber grating sensor not only has many advantages of ordinary optical fiber sensor, but also has its unique advantages. And fiber Bragg grating sensor have a wide range of applications in water conservancy and hydropower, building, bridge, aviation spacecraft, etc.Study on Fiber Bragg Grating Sensors for real-time monitoring of reservoir water levels exploration and research, this topic is designed and completed a fiber Bragg grating sensor is used for water level monitoring system, it can realize network distributed on-line monitoring water level, at the same time to monitor the water temperature, provides an important guiding significance for flood prevention and effective use of water resources. This article main research content is as follows:1. This paper introduces the structure and principle of FBG on the theoretical part, sensing principle of fiber grating are discussed, and simple analyses the strain and temperature sensing properties, describes the cross sensitive solution technology on the FBG sensors, the FBG wavelength detection technology is introduced.2. This paper describes the design and preparation of FBG water level sensor, sensing element of sensor are analyzed in stress, and the maximum deflection has carried on the theoretical calculation under the effect of5meters water depth. In addition, sensing element carried on the finite element simulation, and given it occurrence the amount of displacement and stress distribution under the effect of5 meters water depth. Then introduces the FBG water level sensor structure design and production process. Also on the sensor temperature compensation experiments and data processing and analysis, verity the effect of temperature compensation, at the same time, and temperature compensation coefficient for the calibration.3. In the water level of testing experimental part, the subject carried out the three cycle experiment and its water level test experimental data processing, further concluded the fitting equation that water level h and wavelength shift that strain sensing grating caused by the strain under the action of water pressure. According to the result of data processing on the performance of the sensor is analyzed. At the scale of0-500cm, the accuracy of the sensor is0.5%, the resolution is lcm, the linearity is0.999. The result shows that it featured a good performance.4. Based on FBG water level sensor performance test result made a comprehensive and detailed analysis summarizes, and the reasonable evaluation is given.