Figure 3

Depth profile measurement comparing a sample exposed to a mixture of 50Â ppm O3 and 50Â ppm SO2 for 72Â h to an unaged sample: (a) Changes in the C2 swan band are used to detect polymer degradation and (b) O emission signal indicates oxidation of the investigated paint sample. Average signals and standard deviations are calculated from 210 LIBS spectra recorded per layer.