METHOD FOR DETERMINING THE CONDITION OF ENGINE OIL FOR DIESEL ENGINES Russian patent published in 2022 - IPC G01N31/00 G01N33/00 

FIELD: motor oils.

SUBSTANCE: invention relates to the chemical analysis of motor oils. A method for determining the conditionality of engine oil for diesel engines is described, including taking a sample of deposits from filter elements, dehydrating this sample, dividing into three samples and determining the component and elemental compositions, characterized in that the granulometric and phase compositions of the deposit sample are additionally determined, for which the first sample is divided into parts, each of which is subjected to extraction with an individual solvent: n-heptane, an alcohol-toluene mixture taken in a ratio of 1: 1, dichloromethane, after which each suspension is filtered in random order through a common membrane filter with a pore size of 0.45 μm, get the total concentrate of extracts and the total precipitation on the membrane filter, which are brought to a constant weight by drying and divided into two equal parts, in one of which the phase composition of the sample is determined, and the other part is mixed with one of the original samples, subjected to ashing, the resulting mixture of ash is dissolved in aqueous solution of nitrogen acid, taken in a 1:1 ratio, is mixed with the rest of the extract concentrate and the elemental composition is determined in this mixture, and with a total content of resins, asphaltenes, carbenes and carboids in sediments (∑ CAKK) ≤ 50 wt.%, the total content of iron , aluminum, tin and copper (∑ FeAlSnCu) ≤ 4000 ppm and the total content of calcium and zinc (∑ CaZn) ≥ 1500 ppm engine oil for diesel engines is considered conditioned.

EFFECT: improving the accuracy and reliability of determining the condition of motor oils by expanding the list of analyzes performed and increasing the completeness of studies.

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