Spectroscopy applied to on-road mobile source emissions

The application of Remote Sensing Device (RSD) for the measurement of on-road mobile source emissions from the vehicles driving on the roads, was described. Commercial RSD units use a non-dispersive infrared (NDIR) sensor equipped with a band pass interference filter corresponding to the C-H stretching region around 2970 cm-1 to measure the mobile emissions. A Fuel Efficiency Automobile Test (FEAT) 3000 system that used four thermoelectrically cooled PbSe detectors with cooled filters was designed to measure the level of carbon monoxide (CO) resulting in significant gas mileage improvements. The latest optical FEAT models that use a single detector and are equipped with a spinning wheel carrying five different NDIR band pass filters are being tested to overcome the alignment problems. Remote sensing can be used for regulatory, enforcement, and repair purposes or to inform the public and allow for voluntary action.