Methods for determining air release performance of lubricating oils

Abstract

Provided is a method for determining air release performance of a lubricating oil. The method involves determining air release time of the lubricating oil in accordance with ASTM D3427 at a designated temperature; determining surface tension of the lubricating oil at the temperature used in ASTM D3427; determining kinematic viscosity of the lubricating oil in accordance with ASTM D445 at the temperature used in ASTM 3427; and utilizing the surface tension, ASTM D3427 air release time, and ASTM D445 kinematic viscosity to determine air release performance of the lubricating oil. Surface tension is correlated with ASTM D3427 air release time at an ASTM D445 kinematic viscosity of at least about 30 cSt. The method has higher measurement sensitivity and reproducibility/repeatability than ASTM D3427.

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