ASTM D1721 – Permanganate Time of Tricresyl Phosphate
Tri-cresyl phosphate is used in lubricants and hydraulic fluids as an extreme pressure, anti-wear, flame-retarding additive. Oxidizable impurities in tri-cresyl phosphate may limit its effectiveness. This test determines the presence of oxidizable substances in tri-cresyl phosphate.
A standard solution of potassium permanganate is added to the sample. The mixture is then left undisturbed for the time specified in the test method and the solution is then observed. This is a color indicating test method reported as either a “passing” or “not passing” result.