Articles | Volume 8, issue 1
https://doi.org/10.5194/amt-8-43-2015
https://doi.org/10.5194/amt-8-43-2015
Research article
 | 
06 Jan 2015
Research article |  | 06 Jan 2015

Determination of car on-road black carbon and particle number emission factors and comparison between mobile and stationary measurements

I. Ježek, L. Drinovec, L. Ferrero, M. Carriero, and G. Močnik

Abstract. We have used two methods for measuring emission factors (EFs) in real driving conditions on five cars in a controlled environment: the stationary method, where the investigated vehicle drives by the stationary measurement platform and the composition of the plume is measured, and the chasing method, where a mobile measurement platform drives behind the investigated vehicle. We measured EFs of black carbon and particle number concentration. The stationary method was tested for repeatability at different speeds and on a slope. The chasing method was tested on a test track and compared to the portable emission measurement system. We further developed the data processing algorithm for both methods, trying to improve consistency, determine the plume duration, limit the background influence and facilitate automatic processing of measurements. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions. Measuring EFs at different speeds or slopes did not significantly influence the EFs of different cars; hence, we propose a new description of vehicle emissions that is not related to kinematic or engine parameters, and we rather describe the vehicle EF with a characteristic value and a super emission tail.

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Short summary
We used two methods - the stationary method and the chasing method - for measuring emission factors (EF) of black carbon and particle number concentration in real driving conditions in a controlled environment. We further developed the data processing for both methods. The comparison of emission factors determined by the two methods showed good agreement. EFs of a single car measured with either method have a specific distribution with a characteristic value and a long tail of super emissions.