Optical spectral signatures of liquids by means of fiber optic technology for product and quality parameter identification

Absorption spectroscopy in the wide 200- 1700 nm spectral range is carried out by means of optical fiber instrumentation to achieve a digital mapping of liquids according to their differences or similarities. Extra virgin olive oils from different Italian regions and lubricant oils from tubines with different degrees of degradation were considered as 'case studies'. The spectral data were processed by means of multivariate analysis so as to obtain a correlation to qualtity parameters. In practice, the wide range absorption spectra were considered as an optical signature of the liquids from which to extract product quality information. The optical signatures of extra virgin olive oils were used to predict the content of the most important fatty acids. The optical signatures of lubricant oils were used to predict the concentration of the most important parameters for indicating the oil's degree of degradation, such as TAN, JOAP antiwear index, and water content.