Evaporation Loss (Noack) (75ml) – There are several alternative methods for this test, but the principle of the method includes heating the fluid to a high temperature and measuring the percentage mass loss of the sample after a set period of time.
Tested On: In service Engines and hydraulics, but usually any new lubricants too.
Diagnostic significance: A low result is ideal and a high result suggests the oil will thicken over time as the lighter fractions of the lubricant evaporate off at high temperature. This results in reduced useful life of the oil. Causes of a high result can be blends of light and heavy base oils or contamination/top-up with another product with a different boiling profile to the rest of the lubricant. If a recently changed oil or new oil shows a high value then please consult your lubricant supplier for advice.
Typical Diagnostic limit: Varies dependent on machine OEMs and lubricant suppliers recommendations, but typically a result of 14% or greater would be seen as high. On engine specifications ACEA 2012 A1, B1, A3, B3, B4, C1, C2, C3, E4, E6, E7 and E9 the result must be less than or equal to 13%. ACEA 2012 C4 has a maximum limit of no greater than 11%.