Prediction life of lubricants on the analysis of experimental data on their optical density

The paper presents the results in the field of research and analysis of the optical density of motor oil using mathematical and intelligent models. The quadratic approximations of the dependence of optical density on time are obtained for three different temperatures of temperature control. It is established that each curve of the change in optical density with time contains an inflection point. On the basis of which it was hypothesized that these moments correspond to a certain phase transition in the oil under study. A three-dimensional model of dependence of the rate of change of optical density on temperature and test time was also constructed. When analyzing this dependence, the character of the inflection curve is established, which is proposed as an indicator indicating the attainment of the limiting resource of lubricating oils.