The Reflective Optical Fiber Hydrogen Sensor And Its Hydrogen Sensitivy Testing

The traditional semiconductor hydrogen gas sensor has been invited and has madea great contribution to space technology and research. But the applied voltage intraditional semiconductor hydrogen gas sensors would lead to explosion, which resultedin some limitation in its applications. However, the optical-fiber sensor, which detectsoptical signal, does not cause spark and has various advantages, such as high precision,small volume, light in weight, electric insulation, corrosion resistance, enduring highpressure, electric insulation, low cost, resistant to electromagnetic interference etc. Thus,it becomes a better choice for hydrogen gas detection.And the reflective optical fiber sensor was one of the initial pose and researchoptical fiber sensor, which has simple process. The working principle of reflectiveoptical fiber hydrogen sensor was based on the change of optical properties, such asrefractive index which would cause a variation of optical power absorption ofevanescent field after the Pd/WO₃hydrogen sensitive film exposing into the hydrogengas. And the optical power variation in sensor was used for detecting the hydrogen gasconcentration.The research of reflective optical fiber hydrogen sensor consists of the makingprocess and signal detection method of optical fiber sensor—such as research of sensingmechanism, design of sensor structure, analysis of light wave propagation, preparationof hydrogen sensitive film, property to hydrogen sensitive film etc.Mathematical models were established by using waveguide theory. The makingprocess of reflective optical fiber hydrogen sensor—such as preparation process ofPd/WO₃hydrogen sensitive film and sensor structure etc. was introduced. The specificcontents in this work were as follow:①Introduction of basic principles of reflective optical fiber hydrogen sensor②Designing of reflective optical fiber hydrogen sensor system, and selecting ofrelated parts③The structure, surface morphology, optical properties and preparation of Pddoped WO₃hydrogen sensitive film; analysis the mechanism.④Testing of gas sensing—establish the test system and do the gas sensing testexperiment, find the relationship between light intensity and concentration of hydrogen...