ASTM D5483 Test Method for Oxidation Induction Time of Lubricating Greases
ASTM D5483 Standard Test Method for Oxidation Induction Time of Lubricating Greases by Pressure Differential Scanning Calorimetry
1. Scope
1.1 This test method covers the determination of oxidation induction time of lubricating greases subjected to oxygen at 3.5 MPa (500 psig) and temperatures between 155 and 210°C.
1.2 The values stated in SI units are to be regarded as the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E 473 Terminology Relating to Thermal Analysis
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 extrapolated onset time, n - a time determined on a thermal curve, as the intersection of the extrapolated baseline and a line tangent to the oxidation exotherm constructed at its maximum rate.
3.1.2 oxidation induction time (OIT), n - the period of time from the first exposure to an oxidizing atmosphere until the extrapolated onset time.
3.1.3 pressure differential scanning calorimeter, (PDSC), n - a differential scanning calorimeter, as defined in Terminology E 473, that is capable of maintaining the test sample at a controlled, elevated pressure.
3.1.4 thermal curve, n - a graph of sample heat flow versus time.
