An oil sample is placed into an open top glass vial which is then inserted into a stainless steel pressure vessel. The vessel is then sealed, pressurized, and placed into a heated aluminum block bath for 18 hours. At the end of the 18 hour time period, the vessel is removed from the heat source and allowed to cool to room temperature at which time the contents of the vial are filtered and the total sediment is reported as milligrams of sediment per 20 mL of oil.
This SAE Aerospace Recommended Practice (ARP) is intended to provide acceptable procedure for qualification purposes to determine the tendency of aircraft lubricating oils to oxidatively degrade at elevated temperatures and pressures into products that form suspended fine carbon particles under engine conditions. Properties of such particles may cause filters and other fine passages in the lubricant system to clog.