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Here is an excerpt from the glossary:
Type of wear that occurs between two surfaces in relative motion to each other due to particles (three-body abrasion) or the surface roughness (two-body abrasion).
Refers to the size of the largest spherical particle that will pass through the element.
Term used interchangeably with viscosity to distinguish it from kinematic viscosity; occasionally referred to as “dynamic viscosity”.
The measurement of the acidity of an oil. It is determined by the milligrams of potassium hydroxide required to neutralize one gram of an oil sample. ASTM D664 uses a potentiometric titration; ASTM D974 uses a color-indicator titration. Also known as Neutralization Number."