ASTM D6186 Test Method for Oxidation Induction Time of Lubricating Oils
ASTM D6186 Standard Test Method for Oxidation Induction Time of Lubricating Oils by Pressure Differential Scanning Calorimetry (PDSC)
1. Scope
1.1 This test method covers the determination of oxidation induction time of lubricating oils subjected to oxygen at 3.5 MPa (500 psig) and temperatures between 130 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. Terminology
2.1 Definitions of Terms Specific to This Standard:
2.1.1 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.
2.1.2 oxidation induction time, (OIT), n - a period of time during which the oxidation rate accelerates from zero to a maximum and which corresponds to the extrapolated onset time.
2.1.3 thermal curve, n - a graph of sample heat flow versus time.
