ASTM D6335 Determination of High Temperature Deposits by Thermo-Oxidation Engine Oil Simulation Test
3. Summary of Test Method
3.1 A sample of the engine oil at a temperature of 100°C that contains ferric napthenate and is in contact with nitrous oxide and moist air is pumped at a set flow rate past a tared depositor rod. The rod is resistively heated through twelve, 9.5 min temperature cycles that go from 200 to 480°C. When the twelve cycle program is complete, the depositor rod rinsed of oil residue and dried and the gross rod mass obtained. The sample is flushed from the system and filtered through a tared filter. The mass of deposits on the rod plus the mass of deposits on the filter is the total deposit mass.
4. Significance and Use
4.1 The test method is designed to predict the high temperature deposit forming tendencies of an engine oil. This test method can be used to screen oil samples or as a quality assurance tool.
