Preliminary investigation of the degradation of motor oil by photoacoustic spectroscopy

This paper presents results of the initial stage of investigations concerning the application of photoacoustic spectroscopy technique as a tool for evaluation of lubricating oil degradation degree during its use. Absorbance spectra in 200 divided by 800 nm range and photoacoustic signal spectra in visible range have been determined for two oil samples: the new one and after oxidation during specified time interval (oil wear simulation). Both analysis methods led to similar results indicating the most tangible difference between samples to be found in the exicting light wavelength range below 450 nm.