ISO 4650:2012 specifies two methods for the identification of rubbers, including thermoplastic elastomers, either in the raw state or in the form of vulcanized or unvulcanized mixes.
The first method is based on infrared spectrometric examination using the transmission technique. The second method makes use of analysis by reflectance.
A comparison of the spectra resulting from reflectance (attenuated total reflectance ATR) and transmission (film) is given in Annex A.
