TFOUT = Thin Film Oxygen Update Test utilizes the std Rotary Bomb Oxidation test eqpt. An aluminium inset is placed in the bomb to reduce it's volume. A small beaker is placed on top of the insert which contains 1.5 grams of the test oil. This small samople results in a very thin film of the oil. Added to the sample is 5 weight percent of soluble metal catalysts, 5 weight percent oxidised fuel components and 2 percent water. The soluble metals , oxidised fuel and water simulate the contaminants that an oil is exposed to in an engine from wear debris, blow-by and condensation. The bomb is then reassembled, purged with oxygen and pressurised to 90psi. The bomb is placed in an oil bath where it rotates to provide agitation. The end of the test is time in minutes from placing the bomb in the bath to the point where the bomb chart recorder shows a continuous drop in pressure. The period is referred to as the induction time for the onset of oxidative degradation. The longer the induction time the better the oxidation resistance of the oil. I think I'll file that in the useless info folder!