METHOD OF DETERMINING THERMAL OXIDATIVE STABILITY OF LUBRICANT MATERIALS Russian patent published in 2011 - IPC G01N33/30 

FIELD: chemistry.

SUBSTANCE: method of determining thermal oxidative stability of lubricant materials includes the following operations: heating lubricant material in the presence of air, stirring, photometric determination coefficient of absorption of light flux, testing a sample of the lubricant material having a constant volume at optimum temperature selected depending on the base of the lubricant material and group of operational properties in a period of time characterising the same oxidation level. Samples of the oxidised lubricant material are taken at equal time intervals. The sample of oxidised lubricant material is divided into two portions. The first portion undergoes photometering and the coefficient of absorption of light flux is determined. The second portion is tested on a friction test machine with a ball-cylinder scheme for not less than 2 hours. The size of the wear scar on the ball is determined and a curve of the size of the wear scar versus the coefficient of absorption of light flux is plotted, from which thermal oxidative stability is determined.

EFFECT: high reliability of evaluating thermal oxidative stability of lubricant materials by obtaining additional information on variation antiwear properties to different oxidation level of lubricant materials.

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