IR spectroscopy allows the identification of different polymers by comparing spectra with databases. Simple material mix-ups can thus be reliably excluded. IR spectroscopy can also be used to characterise the main components of paint systems.
To determine the glass fibre content, the annealing residue of a sample is determined. While organic components burn during annealing, the inorganic glass fibres remain in the crucible. Their proportion can be determined by weighing.