机动车尾气的道边在线实时监测(下)

On-Line Roadside Vehicle Emissions Monitoring (Part 2)

利用调谐二极管激光器吸收光谱和紫外差分吸收光谱原理研制了道边实时监测机动车尾气仪,详细讨论了该仪器对几种主要有害气体如CO,CO2,NOx和HC(分别用NO和丁二烯代表)的测试及校正原理,以及各种环境因素对测试结果的影响.全文分上、下两部分.本部分(下)介绍了该仪器的主要技术难点、创新点和性能参数,报道了用该仪器跟美国M D-L aserT ech公司商业化产品在北京测试现场的部分路边测试实验结果,讨论了各种环境因素如天气、车型、季节、车速、路况等对测试结果的影响及校正.对仪器的性能参数跟国外同类仪器比较发现,我们研制的仪器性能略优于国外同类仪器90年代后期水平.本技术拥有完整自主知识产权,填补了国内空白.

In the whole paper we will describe an on-road vehicle emissions monitor fabricated recently in our laboratory employing tuneable diode laser absorption spectroscopy （TDLAS） and ultraviolet differential optical absorption spectroscopy （DOAS） techniques. A detailed discussion on how to calibrate the instrument and measure the concentration of few major polluting gases including CO, CO2, NOx and HC （with NO and butadiene instead, respectively） is described. The whole paper consists of two parts. This one is the second part in which the major technical difficulties, the main innovative points and the specifications are reported. A little portion of roadside test results taken at two locations in Beijing, the operational difficulties and the effect to the measurement results from various environmental factors including weather, vehicle model, vehicle speed, road condition and optical alignment are presented. A direct comparison of the test results made by our system and a commercial TDLAS instrument purchased from MD-LaserTech is also carried out. The roadside tests show that two instruments perform similarly on the measuring specifications, even our system behaves slightly better than the overseas instrument manufacture at late nineties of 20 century. The whole intelligent right is hold by our institute and the gap is supplied.