This method is used for determining the compatibility of a candidate lubricant with specific reference lubricants. The reference lubricants will typically be mandated by the product specification against which the candidate lubricant is being compared. This method is based on Federal Standard 791 method 3403 and Defence Standard 05-50 (Part 61) method 24, incorporating the modifications called for in SAE AS5780.
Rationale: Any new lubricant used to in a system must be fully compatible with any lubricant that is likely to have been used previously in that system, in order to avoid incompatibility issues such as loss of performance or filter blockage, which could lead to equipment failure. This method looks specifically at fluid miscibility and particulate formation when mixing a candidate lubricant with specific reference lubricants.