METHOD FOR ACCURATE DETERMINATION OF DISPLACEMENT FACTOR AND RELATIVE PERMEABILITY Russian patent published in 2012 - IPC G01N25/02 

FIELD: physics.

SUBSTANCE: method of determining thermo-oxidative stability of lubricating materials involves heating the lubricating material in the presence of air and mixing. Oxidised lubricating material is then collected. Oxidation process parameters are then photometered and determined using graphical curves. Two samples of the lubricating material of constant weight are tested separately with and without a catalyst. While heating, the two samples of lubricating material of constant weight are tested successively with and without a catalyst, stirred while periodically varying testing temperature from temperature at the onset of oxidation and maximum temperature. Temperature is the lowered from maximum temperature to temperature at the onset of oxidation over a constant period of time. After each testing temperature, with and without a catalyst, the samples are weighed, the weight of the evaporated sample and evaporation number are then determined as a ratio of the weight of the evaporated sample to the weight of the remaining sample. By photometering, the light flux absorption factor with and without catalyst is determined, the thermo-oxidative stability factor is determined as a sum of light flux absorption factor and evaporation number. Further, the influence coefficient of the catalyst K_VK on oxidative processes is determined using the formula K_VK=K_K/K, where K_K and K are thermo-oxidative stability factors of samples of the lubricating material with and without catalyst, respectively. A curve of the influence coefficient of the catalyst on the oxidative processes versus the testing time is then plotted, and thermo-oxidative stability of the lubricating materials is then determined from values of the influence coefficent of the catalyst on the curve. If K_VK>1, thermo-oxidative stability is falling, and if K_VK<1 thermo-oxidative stability is increasing.

EFFECT: high information content of the method of determining thermo-oxidative stability of oxidation and evaporation processes during periodic variation of the testing temperature.

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