Testing of the synchronous fluorescence in application to used lubricate oil characterisation

Reliability of the ship propulsion system depends, inter alia, on the quality of lubricate oils. Research indicates that exploitive features of oil are reduced with it runtime in the ship engine circuit. At the present the basic parameters representing exploitive features of oil are: water content, total acid number and total base number or viscosity vs. temperature, anti-wear performance, further: content of additives and their concentrations, reaction products, and other contaminating substances, also magnetically separated large ferromagnetic particles, the size, the shape, the composition and concentration of the abnormal wear particles. Additional properties of oil are described based on atomic emission spectroscopy, granulometry of separated from the lubricant sample by magnets and gravity, permeability changes, as well as rheometric and tribometric characteristics. Complexity of composition of lubricate oil raises the idea to use changes of relative content of any compounds for characterization of oil exploitive features. Fluorescence method is possible to use for oil properties characterisation due to the presence mono and polycyclic compounds in oil that induces fluorescence phenomenon. Therefore identification the fluorescence spectra when exploitation time of oil increases could be novel indicator to monitor of lubricate oil exploitive quality. In this study we present changes of oil fluorescence expressed by synchronous spectra, taking into account working time of exemplary lubricate oil in the ship engine.