北京市轻型汽车尾气排放检测结果分析

对北京市566辆在用轻型车排放尾气进行了BASM检测，对不同厂牌的化油器车、化油器改造车和电喷车排放的HC、CO和NO平均浓度进行了比较，结果表明，化油器改造车3种污染物平均浓度比化油器车低50％左右，电喷车3种污染物平均浓度可比化油器车低80％左右。同时对几种车型的劣化规律进行了分析，发现化油器车的劣化关系离散性大，而另外两种技术的车辆的劣化关系呈收敛性，说明化油器车的污染物排放和保养关系密切，电喷车劣化规律明显优于化油器车和化油器改造车。实验结果为I／M实施提供了科学依据。

The Tested Results Analysis of In-use Light Duty Vehicles Emission in Beijing

In this study, BASM tests were done on the exhaust emission of 565 in-use light duty vehicles in Beijing. Through the compaison of the average concentrations of HC, CO and NO emitted by the three types of vehicles,carburetor, retrofit-carburetor and EFI, it showed that the average concentrations of the three pollutants of the retrofit-carburetor were about 50% lower than that of the carburetor .while those concentrations of the EFI were about 80% lower than that of the carburetor. Through the analysis of the deterioration rate of the three types of vehicles, it was found that the deterioration relationship of carburetor was dispersed hut that of retrofit-carburetor and EFI is astringent. So that showed that the pollutant emission of carburetor is closely related with the maintenance and the deterioration rate(DR) of EFI is better than the other two. The result of the experiment provides scientific base for the implementation of I/M system.