ISO 4263-1:2003 specifies a method for the determination of the ageing behaviour of rust- and oxidation- inhibited mineral oils having a density less than that of water, used as turbine oils (categories TSA, TGA, TSE, TGE of ISO 6743-5, hydraulic oils (categories HL, HM, HR, HV, HG of ISO 6743-4), and circulating oils (category CKB of ISO 6743-6). Oils containing synthetic components can be tested by this procedure, but no precision statement is available yet for such fluids.

This test method is widely used in specifications and is considered of value in comparing the oxidation stability of oils that are prone to contamination with water. However, because of the large number of individual field service applications, the correlation between the results of this test and actual service performance can vary markedly, and is best judged on experience.