An oil of known performance characteristics, used as a basis for comparison.
Double-Blind Reference Oil
A reference oil, the identity of which is unknown by either the submitting source or the test facility and is not known to be a reference oil by the test facility.
This is a coded reference oil that is supplied by an independent source to a second party, who applies their own coded designation to the oil, and submits it to a third party for testing.
Any oil other than a reference oil; such as a research formulation, commercial oil or candidate oil.
See also: Oil.