Research On UV Differential Algorithm And Software Design Of Vehicle Exhaust Measuring Instrument

With the increasing of the number of vehicle, the vehicle exhaust has become main source of air pollution which also makes environmental pollution more badly. We must grasp the source and rigorously in order to measure and control vehicle exhaust. As the new national standard has started, the measuring limit is more seriously. We should measure and control the vehicle exhaust by stable and accurate gas analytical measuring system. In this paper, a method based on differential optical absorption spectroscopy (DOAS) technique is developed for vehicle exhaust measuring. It can provide forceful guarantee for vehicle exhaust contamination control to gain the ends of protecting environment.The paper introduces the sort and harm of vehicle exhaust pollutation, combining with the"Gas Pulluation Detecting Methods of the Nation", and make a detail analysis to SO2 and NOx measuring methods, then we put forward DOAS technique which can realize multicomponentand on-line detecting of vehicle exhaust pulluation. The fundamentals theory and the configuration instrument of DOAS as well as differential optical path are discussed. We design the vehicle exhaust measuring software with Laboratory Virtual Instrument Engineering Workbench (LabVIEW), which realizes the spectrum collection, data processing, display and save. In the DOAS data processing algorithm, we research on the multiple linear regression model and the least-square method and make a standard gas experiment indicated that the system can fulfill the requirements of the on-line measuring for vehicle exhaust with a proper measurement accuracy and stability.It is shown in the research and experiments that the DOAS has wide application prospects. The studying of this paper provides the theoretic and experimental bases of the DOAS applied successfully in vehicle exhaust measuring, and provides the technical support to improve vehicle exhaust measuring level.