Exposure of Cyclists to Ultra Fine Particles - Highway and Urban Environment - page 108

Fig. 1 Case study site along the N18 in Mol, Belgium
Fig. 2 Experimental set-up for validation of the methodology. ( a ) Sampling at 1 m above the
ground for both instruments. ( b ) Sampling at 0.8 and 1.6 m above the ground. ( c ) Sampling in
different directions at the same height. ( d ) Set-up to determine the effect of distance on UFP
exposure on the cycling track. The horizontal distance between both sampling tubes was 2 m in
the pilot test and 1 m during the final test
Subsequently the effect of sampling height (Fig. 2 b) and sampling direction
(Fig. 2 c) were tested. Subsequently the bicycle was set-up to measure UFP concen-
trations on a cycling track in the city of Mol. Simultaneous measurements were
taken at a horizontal distance of 2 m while cycling (Fig. 2 d). Measurements were
taken during trips in both directions on three different days in November 2007
(N = 6). The main purpose was to determine the set-up and number of replicates
necessary to resolve the expected difference.