A significant proportion of the atmospheric pollution that exists particularly in urban areas arises from road vehicles and primarily cars. The European Commission (EC) have introduced a series of regulations, the so called EURO Emission directives from Euro I in 1991 to the present day Euro IV. This legislation and similar ones in other global regions have helped to greatly reduce emission levels from road transport. However, a massive increase in the number of cars on the road have meant that pollution due to a number of gases and particulate species remains to be a problem. This paper describes an approach based on optical fibre sensors which has shown to be an effective means of measuring the gases and particulates in question by using sensing technologies which are both robust and potentially cost effective such that they may be included as part of an on board monitoring system for the car of the future.

This paper describes an optical fibre sensor for the detection of NOx (NO2 and NO) and CO2 in the exhaust system of a road vehicle. The measurement is based on a free path interaction zone which is interrogated using UV and NIR light guiding optical fibres and collimated lenses. Results are presented in the absorption spectra of the gases in the UV region for the NOx gases and NIR region for CO2. These demonstrate that using this method it is feasible to identify the individual CO2, NO and NO2 species as well as other gases in the exhaust system. Measurement of concentrations to the level of ten's parts per million (ppm) have been demonstrated for the NOxx gases.

This paper describes an optical fibre sensor for the Detection of NOx (NO2 and NO) in the exhaust system of a road vehicle. The measurement is based on an a free path interaction zone which is interrogated using UV light guiding optical fibres and collimated lenses. Results are presented of the absorption spectra of the gases in the UV region and these demonstrate that using this method it is feasible to identify the individual NO and NO2 species as well as other gases in the exhaust system. Measurement of concentrations to the level of 10s parts per million (ppm) have been demonstrated.

This paper describes an optical fibre sensor for the Detection of NOx (NO2 and NO) in the exhaust system of a road vehicle. The measurement is based on an a free path interaction zone which is interrogated using UV light guiding optical fibres and collimated lenses. Results are presented of the absorption spectra of the gases in the UV region and these demonstrate that using this method it is feasible to identify the individual NO and NO2 species as well as other gases in the exhaust system. Measurement of concentrations to the level of 10s parts per million (ppm) have been demonstrated.