EXPLANATION
This is a safe and fast alternative for the determination of Noack evaporation loss of a lubricant. This test method is applicable to base stocks and fully formulated lubricating oils having a Noack evaporative loss from 0 to 30 mass %. This procedure requires a much smaller sample size. The evaporative loss determined by this test method is the same as that from the standard Noack method.
TEST SUMMARY
A lubricant sample is placed in an appropriate TGA specimen pan that is placed on the TGA pan holder and quickly heated to between 247 and 249° C under a stream of air, and then held isothermal for an appropriate time. Throughout this process, the TGA monitors and records the mass loss experienced by the specimen due to evaporation. The Noack evaporation loss is subsequently determined from the specimen's TG curve versus the Noack reference time determined under the same TGA conditions.
TEST PRECISION
This test method has a repeatability of
and a reproducibility of 
, where X is the TGA Noack volatility.No significant bias was found between the Noack volatility determined by this test method and that determined by Test Method ASTM D5800, Noack Method, within the repeatability of the test method.