Emission factors for ethene and ammonia from a tunnel study with a photoacoustic trace gas detection system

Efforts are being made to develop a system that can determine the ethene and ammonia concentration individually in the analysis of polluted ambient air. Catalytic converters, although known to reduce most of the toxic compounds in the exhaust stream of a car, can substantially increase the emission of ammonia. On-road studies that account for the emissions of a large number of in-use vehicles are therefore indispensable to assess a realistic amount of an emitted pollutant. A mobile photoacoustic trace gas detection system, which is built in a trailer and can easily be moved to different sites of interest has been built for this purpose. The details of the trace gas detection system are discussed further.