Study Of Concentration Intelligent Measurement System Of Sulfur Dioxide Based On Fluorescence Technology

With the development of economic,environment pollution becomes more and more serious. One of major pollutants, sulfur dioxide ,has done great harm to our environment, so it is more and more necessary to set up an consummate sulfur dioxide detecting sysrem. The paper has analyzed the methods about measuring the concentration of sulrur dioxide and detector for concentration of sulfur dioxide in atmosphere abroad and at home at present. We have developed a kind of intellectual detector which based on ultra-violet fluorescence.First of all, based on the fundamental theory of fluorescence measurement, this paper demonstrated the sulfur dioxide fluorescence detection principle and linear correlations beteew the fluorescence intensity and the SO2 concenrations under the sigle wavelength. Making sure that the relationship betweeen the fluorescence intensity and the SO2 concenrations under the multiple wavelength that can be used as the basis of theory and experiment for sulfur dioxide contaminaion measurement. Afterwards combining with double optical-paths and two wavelength thought, the paper studied weak fluorescence measurement technique, designed the optical-fiber fluorescence measurement system and built the math-model. Finally the research designed singlechip controlling and data processing system and made the system intelligentize.In the aspect of fluorescence measurement system, the paper made study respectively through optical path system and circuit system. First ,the paper thought about the electrical noise associated with the flash fluctuated and studied two optical-paths technique. The optical system which comprise of Xe flash lamp trigger, the low-loss silicon optical-fiber bundle, measurement room was designed. secondly detection technique of weak fluorescence was studied and double detection circuit which comprise of PMT, PIN detector, the circuit of signal amplified, the circuit of low-pass filter and Boxcar integrator was designed. At last, the research finished picking up the weak fluorescence from measured signal with noise.In the aspect of intelligentize system, the research mianly thought about the data transmit, data manage, and data storage and data control and so on. The singlechip control system was finally designed, which use the PIC16F877 as the center processor. The research designed singlechip controlling and data processing system, we put up the hardware circuit, designed the relative software of function. Finally,the research finished designing of interface and database using Visual C++ and SQL server 2000 software. The system has achieved system controling, data collecting, processing, storage, communication, display, print function and so on .The research finally finished relational experiment study of sulfur dioxide detection system, analysed the result of experiment and validated the feasibility of system.