Design And Experimental Research Of Optical Fiber Hydrogen Sensor Based On Intensity Modulation

Hydrogen as one of the most important clean energy has been widely used in various fields to meet the demand for energy in modern society. But hydrogen is chemically active and explosive, of which dangerous concentration is 4.0%-74.5%. Therefore, it is of great value and significance to develop a hydrogen sensor with good reliability, high sensitivity and fast response to monitor the concentration of hydrogen.Fiber optic sensors have unparalleled advantages over other types of sensors, such as: good corrosion resistance and anti-electromagnetic interference capability, low cost, light weight and small size. After looking up a large number of domestic and international literature on optical fiber hydrogen sensor, a design project of sensing system of optical fiber hydrogen sensor based on intensity modulation has been presented in this paper. This design project focuses on using software method to detect and process weak signal, as well as optimizing and improving the preparation technology of hydrogen sensitive film, in the end, verifying the results by doing experiments. The dual optical fiber sensor probe of hydrogen and hydrogen gas chamber platform has been designed and optimized in order to facilitate testing and validation experiments. Meanwhile, selection of key components such as optical fiber, light source and so on has also been completed.Compared to the use of hardware processing weak signal, virtual instrument Labview software has been used to capture weak signals in this article, which has the advantage of stability and high precision. After designing pre-amplification electric circuit and studying digital filter technology, optical fiber hydrogen sensors weak signal detection system has been accomplished ultimately. In order to solve the aging problem of Pd-Y alloy film, the way of thermal treatment is proposed, which can improve the crystallinity of the film, eliminate the internal stress and make the sensor work better.Through analyzing experiments process and relevant experimental data, optical fiber hydrogen sensor based on intensity modulation presented by this article shows a high sensitivity, stability and low zero drift. For deficiencies in the present study, future research directions have also been presented in this paper.