The results of an experimental study of the diagnosis of high-alkaline motor oils by the way of "drop sample"
The problems associated with improving the reliability and durability of internal combustion engines, largely depend on the quality of the FCM used. This dependence exists and progresses due to a change in the form of ownership, the emergence of new oil producers, a significant number of uncertified, fake TCM, deviations from the rules of the preventive maintenance system. The system of quality control of petroleum products that existed in the mid-eighties assumed the presence of stationary laboratories for chemical and spectral analysis of FCM, as well as express laboratories. At present, such a system does not exist; in addition, the previously used most simple method of “drop test”, widely recommended in the technical literature for assessing the quality of oils, does not give results in the analysis of modern high-alkaline motor oils. The question arises: the impossibility of forming concentric zones when analyzing a drop sample of high-alkaline oils is a fundamental disadvantage, making it unsuitable for diagnosing these oils, or the formation of zones and their manifestation on filter paper is a consequence of the influence of some other factors on the formation of concentric zones. To confirm the results of theoretical studies developed a program and methods of experimental research. The tests were carried out on Neste Tyrbo LXE SAE 15W-40 and BP Vanellus C6 Global (U) 15W-40 oils. By experimentally determining the diameter of the core zone, the coefficient γ = 2.62 · 10<sup>-18</sup> was obtained, which made it possible to obtain an equation for determining the diameter of the core zone. When determining the diameter of the diffusion zone, a factorial linear experiment to displace the additive particles during the observation period was performed. As a result of the implementation of the full factorial experiment, the dependence of the additive particle displacement on filter paper on the viscosity, the base number of the oil being analyzed and the density of filter paper in natural factors was obtained.