On-board measurements of particulate matter emissions from a passenger train

Artikel i vetenskaplig tidskrift, 2011

A number of measurements of particle emission from railways are presented. The measurements featured a particle instrument mounted in a compartment under a Regina train. The particles were probed in a volume between the coaches. The measurements were done in two campaigns and provide information on how the particle emissions vary with driving patterns. The measurements showed elevated particle concentrations when the train was running. Further, sharp peaks in the particle concentration were observed. It was noted that these peaks coincided with retardation of the train. However, there are also retardations where no peaks were observed. This can be explained from the two parallel breaking systems, one with regenerative breaking and one with mechanical breaks that are present on the Regina train. It is suggest that the observed peaks coincide with the use of the mechanical breaks. It was not possible to fully establish that increased particle concentration coincides with curvature of the rail, even though this was indicated in parts of the data. The size-resolved data showed maxima for the smallest fraction (350 nm) for the number distribution.