1.1 This test method covers the oxidation stability of lubricants by thin-film oxygen uptake (TFOUT) Catalyst B. This test method evaluates the oxidation stability of petroleum products, and it was originally developed as a screening test to indicate whether a given re-refined base stock could be formulated for use as automotive engine oil (see Test Method D 4742). The test is run at 160°C in a pressure vessel under oxygen pressure, and the sample contains a metal catalyst package, a fu