Optical fiber spectroscopy for measuring quality indicators of lubricant oils

A collection of lubricant oils from different types of turbines, which were characterized by different degrees of degradation, were analyzed by means of UV-VIS-NIR absorption spectroscopy, fluorescence spectroscopy and scattering measurements. All these measurements were performed by means of optical fiber-based instrumentation that made use of LEDs or compact lamps for illumination and miniaturized spectrometers for detection. Multivariate data analysis was used to successfully correlate the wide optical spectral signature of lubricant oils to some of the most important parameters for indicating the degree of degradation of the oil, such as TAN, JOAP-index, water content, and phosphorus.