Research On Liquid Level And Temperature Sensor Based On F-P And FBG Composite Structure

In the fields of fuel storage and chemical level measurement,liquid level sensors and temperature sensors are very important for the real-time monitoring of high precision liquid level and temperature.At present,most electrical sensors are used when measuring these two physical parameters.The traditional electrical sensor technology is more mature,it has the advantages of low cost,but the electrical sensor also has complex wiring,easy to electromagnetic interference and other problems,not suitable for use in flammable and explosive places.For this reason,based on reading a lot of literature,this paper proposes a solution of an optical sensor suitable for liquid depth and temperature detection.According to the actual process requirements of the test,the following theoretical analysis and experimental research were carried out:Firstly,the development status and technology trend of optical fiber liquid level sensor,temperature sensor and composite structure sensor are discussed in depth.Secondly,the basic principle of optical fiber liquid level sensor and temperature sensor is analyzed,which provides theoretical support for the design of composite optical fiber liquid level sensor and temperature sensor.On the basis of basic principle analysis,the sensing mechanism of Fabry-Perot interferometer and fiber Bragg grating composite structure sensor is studied.The reflection spectrum of composite structure is obtained by software simulation and the appropriate algorithm is selected.Then,based on the actual needs of detection,choose the suitable sensing element material,and the size parameters of the sensing element theory analysis and simulation,the design method of the cloth-perot interferometer in the composite structure of optical fiber Bragg grating sensor,and general packaging scheme of sensor is put forward,after the encapsulation of the features of the composite structure of the sensor in-depth study;Finally,a sensor experiment platform was built to verify the temperature sensing and liquid level sensing performance of the composite structure sensor,and the experimental results were analyzed and discussed in detail.The experimental results show that the sensor has good stability and repeatability.The composite structure sensor designed in this paper has good linearity and repeatability,and has the advantages of low cost,simple structure,convenient production and so on.It can be used to measure the temperature and liquid level in the flammable and explosive environment.The research results can also provide a new idea for the design of the composite structure sensor with double parameter measurement.