The Study And Design Of Dissolved Oxygen Potency Sensor Based On Luorescence Quenching Principle

Oxygen molecules dissolved in water or other liquids due to certain chemical reactions are called Dissolved Oxygen(DO).Oxygen dissolved in water is indispensable for the vital activities of creatures living in the water,also is the important index to measure water quality and water conditions.With the social development and technical advances,large amount of industrial wastewater and chemical polluted water are steadily discharged into the oceans,while the other pollution factors such as automobile exhaust,carbon dioxide emissions have also directly or indirectly caused serious damage to various water resources,water environment and aquatic ecosystems,and affected the nature balance of the water circulation.Therefore,the development of high-precision DO concentration sensor for accurate information on the content of DO in the water at any time possess very important sense.With the fluorescence lifetime imaging and fluorescence quenching as the basic detect method and design principle,a DO concentration sensor with high precision,high sensitivity,high stability and low consumption has been designed and developed by integrating the knowledge theories in various disciplines such as control science,electronics,optics,chemistry and computer science,adopting the technical methods such as circuit design,detection of phase,signal processing,photoelectric sensing,Phase-Locked Loop technology and software design,combining with system analysis and system modeling,and using optical design,chemical modulation,cut-noise analysis and experimental correction as auxiliary means,then finally conducts relevant debug test and calibration experiment on the sensor prototype.This paper successively introduces the research background and research significance,summarizes the relevant progress and research status of DO concentration detection technology at home and abroad,proposes the research objectives and major contents of this paper,briefs its basic contents,briefly introduces the basic design principles of the system such as fluorescence quenching,phase sensitive detection and Phase-Locked Loop,introduces the detection principle and structure of the system,and provides the specific design methods of every section of the system such as the sensing membrane,optical structure,function circuit module,core domination unit and so on.The software contents such as the master program for the host/slave computers,program for the every function mission,comprehensive calculation method,host computer softwares,relevant algorithm and so on are designed.Finally the sensor prototype is tested and calibrated,the test results are comprehensively analyzed and the basic performance parameters of the sensor are presented.According to the test results and basic parameters,the sensor has performed well in various aspects and has fulfilled detection or other tasks satisfactorily,achieved the expected design effects and requirements.