A field evaluation of a piezo-optical dosimeter for environmental monitoring of nitrogen dioxideElectronic supplementary information (ESI) available: Fig. ESI 1 Time profiles of the ozone concentrations for the five days (uv instrument data). Fig. ESI 2 Temperature profiles (site G) for the five days. Fig. ESI 3 Wind directions (top) and speeds for the five days (site G). In the direction plots, the lengths of the lines indicate the relative times in each direction and the times of day in each direction are shown as numbers. See http://www.rsc.org/suppdata/em/b4/b401495m/