Analysis of Uncertainty of the Emission Measurement of Gaseous Pollutants on Chassis Dynamometer

This paper evaluates the accuracy of emission measurement of regulated gaseous pollutants from vehicles tested on chassis dynamometers. The paper describes sources of error during exhaust emissions measurement. A model of uncertainty using statistical analysis and standard uncertainty propagation techniques has been used. The model, based on individual uncertainties of different instruments used in the measurement process, as well statistical analysis evaluating uncertainties resulting from the errors introduced by the vehicle, the driver and the chassis dynamometer were all used to compute the total uncertainty of the emission measurement.

The paper shows that current CVS system and analytical techniques used to measure exhaust emissions are not sufficient to meet Euro 5 standards. Either an improvement to the CVS system or the development of a new emission sampling system is a prerequisite to measure the emissions from vehicles complying with Euro 5 or SULEV.