title: Characterization of used mineral oil condition by spectroscopic techniques.
abstract: Optical absorption, fluorescence, and quantitative 13C NMR spectroscopy have been used to study the degradation of mineral gearbox oil. Samples of used oil were collected from field service. Measured absorption, fluorescence, and quantitative 13C NMR spectra of used oils show characteristic changes from the spectra of a fresh oil sample. A clearly observable, approximately 20-nm blueshift of the fluorescence emission occurs during the early stages of oil use and correlates with changes in intensity of some specific 13C NMR resonance lines. These changes correlate with oil age because of the connection between the blueshift and breaking of the larger conjugated hydrocarbons of oil as a result of use.
authors.affiliation: Department of Physics, University of Jyväskylä, FIN-40014, Jyväskylä, Finland. jarmo.vanhanen@phys.jyu.fi
authors.forename: Jarmo
authors.initials: J
authors.lastname: Vanhanen
authors.forename: Marcus
authors.initials: M
authors.lastname: Rinkiö
authors.forename: Jukka
authors.initials: J
authors.lastname: Aumanen
authors.forename: Jouko
authors.initials: J
authors.lastname: Korppi-Tommola
authors.forename: Erkki
authors.initials: E
authors.lastname: Kolehmainen
authors.forename: Tuula
authors.initials: T
authors.lastname: Kerkkänen
authors.forename: Päivi
authors.initials: P
authors.lastname: Törmä