Fluorescent UV Method SO₂Concentration Detector Design

With the development of industry, the sulfur dioxide （SO₂） harmful gas worseningpollution, our country higher concentration SO₂in many cities. At present domestic SO₂concentration of gas detector to rely mostly on import, the price is expensive, therefore,design a kind of economic and practical method based on fluorescent uv SO₂concentrationdetector.Hardware design: detection of the photomultiplier tubes （PMT） to realize thetransformation of the fluorescence intensity, the data acquisition module by16roadMC14067B multi-channel analog switch and24bits A/D conversion ADS1255constitute, Amachine adopts LPC2138microprocessor as the central processor, use of RS-232to realizeserial communication, through the SED1335LCD and PC machine to implement the outputshown.The software design; Written in C the next place machine program, ADS1.2developmentenvironment in finish the program to load. Through each function modules of the son programdesign, and enhanced the system initialization, interrupt sampling, data real-time display,historical data storage, sound and light alarm and data communications, softwareanti-jamming. With VC++language to write the PC testing interface.The experiment test: the American TE company Model type111zero gas generator andModel146type with gas system configuration sample gas, the concentration of1.434（mg/m³）SO₂sample gas to test, get average of1.437（mg/m³）. The0.289,1.430,2.869,14.388,57.434, and114.571（mg/m³） six different standard concentration samples were tested, andthe relative error less than2%.The results show that the data type ML9850B SO₂detector contrast, the design of theinstrument error about0.011. measuring relative error of±0.02. SO₂concentration detectordesign can be used for the detection of SO₂concentration commonly.