METHOD OF DETERMINATION OF THERMAL-OXIDATIVE STABILITY OF LUBRICANTS Russian patent published in 2017 - IPC G01N33/30 G01N25/00 

FIELD: physics.

SUBSTANCE: samples of a constant-mass lubricant are tested in the presence of air at optimum temperatures below the critical temperature, chosen depending on the base of the lubricant and the group of performance properties, for a time period characterizing the same degree of oxidation. At regular intervals a sample of oxidized lubricant is taken, scanned photometrically, the parameters of thermal-oxidative stability are determined, and the oxidation process is evaluated. The samples of a constant-mass lubricant are tested with or without agitation, the optical density is determined by photometry, some of the thermostated sample is used to measure the kinematic viscosity at temperatures of 40 and 100°C, the viscosity index is determined, a part of the sample is used to determine the anti-wear properties, and the thermal-oxidative stability of the lubricant under study is determined from the ratio of the product of the optical density by the decimal logarithm of the viscosity index to the anti-wear index. Characteristic curves of the thermal-oxidative stability value and the optical density of the thermostated lubricant are constructed for the cases when the lubricant is tested with or without agitation, which determine the influence of the oxidation products and temperature destruction on the value of the thermal-oxidative stability index.

EFFECT: increase in the information content of the method for determining the thermal-oxidative stability of lubricants.

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