METHOD FOR DETERMINING THE EFFICIENCY RANGE OF LUBRICANTS Russian patent published in 2018 - IPC G01N25/12 G01N33/30 

FIELD: measurement technology.

SUBSTANCE: invention relates to technology of assessment of liquid lubricants quality. Proposed is a method for determining the temperature efficiency range of lubricants in which a lubricant sample is tested in the presence of air with stirring, constant mass, minimum at three temperatures chosen depending on the base substrate and the group of performance properties, for a time characterizing the same oxidation degree. According to the invention, the oxidized lubricant sample is being thermostated to a specified optical density, after each test time period at each temperature, the oxidized lubricant sample is being weighed, mass of the evaporated portion of the sample and the rate of volatility as a ratio of the evaporated portion of the sample to the mass of the sample before testing are being determined . Portion of the oxidized lubricant sample is taken, photometry is being performed, the optical density and the index of thermooxidative stability are being determined as the sum of the optical density and volatility coefficient. Graphic dependencies of optical density, evaporation and the index of thermooxidative stability on the time and test temperature are being constructed, according to the graphs, the time of reaching the specified values of optical density, volatility and the index of thermooxidative stability, as well as the values of these indicators for the given test time at each temperature are being determined. according to the data, graphic dependencies of time of reaching the specified values, optical density, evaporation and the index of thermooxidative stability, graphic dependencies of optical density, evaporation and the index of thermooxidative stability during the given oxidation time on test temperature are being constructed, according to the dependencies the temperatures of beginning of processes of oxidation, evaporation and changing of the index of thermooxidative stability of the tested lubricant and the critical temperatures of these processes are being determined, and the temperature efficiency range is being determined according to the lowest temperature values of beginning of processes and critical temperatures.

EFFECT: shorter test time and ensuring the possibility of comparing different lubricants for resistance to oxidation, evaporation and changes in thermooxidative stability in the given temperature range.

1 cl, 9 dwg, 2 tbl