ASTM D2595 Test Method for Evaporation Loss of Lubricating Greases
ASTM D2595 Standard Test Method for Evaporation Loss of Lubricating Greases Over Wide-Temperature Range
4. Summary of Test Method
4.1 A weighed sample of grease in an evaporation cell is placed in a heating device maintained at the desired test temperature. Heated air is passed over the grease surface for 22 ± 0.1 h. The loss in weight of the sample due to evaporation is determined.
5. Significance and Use
5.1 The loss of volatile materials from greases and oils can adversely affect the original performance characteristics of a lubricant and, therefore, could be a significant factor in evaluating a lubricant for a specific use. Such volatiles can also be considered contaminants in the environment in which the lubricant is to be used. Correlation between results from this test method and service performance has not been established.
5.2 The test method can be used at any specified temperature between 93 and 316°C (200 and 600°F) that may be agreed upon by the user of the method. (Warning - This test method should not be used at temperatures which exceed the flash point of the base oil of the grease.)
NOTE 1 - The specified flow of air, 2.58 ± 0.02 g/min, (2 L/min at standard temperature and pressure), assumes dry air. It is not known that the original work involved dry air but it has since been shown that this can be a factor in reproducibility and should be addressed. Air with a dew point of less than 10°C at standard temperature and pressure will be satisfactory.
