ASTM E1858: Oxidation Induction Time of Hydrocarbons by DSC

ASTM E1858 Determining Oxidation Induction Time of Hydrocarbons by Differential Scanning Calorimetry

Lubricants may react with oxygen to produce acids, varnish, sludge and viscosity changes. The rate of oxidation increases with temperature and in the presence of water, acids and metals. This test measures the relative oxidative stability of lubricants, fats or oils.

The sample is placed in the PDSC (pressure differential scanning calorimeter), pressurized with oxygen and heated to the test temperature. The time it takes for an oxidation exotherm to start is determined and reported. This method has two options: Test method A is run at atmospheric pressure with an oxygen purge. It is typically run at 195°C. Test Method B is run at 500 psi oxygen and 175°C.

Related tests: Petro-Lube offers a variety of differential scanning calorimetry tests. For the specific heat consider ASTM E1269. For thermal conductivity consider PLTL-73. For thermal characteristics including phase changes consider PLTL-108. For oxidation onset temperature consider ASTM E2009. For oxidation onset times in an oxygen atmosphere consider ASTM E1858 for ambient pressure, and ASTM D5483 (grease) or ASTM D6186 (oil) for 500 psi. Consider CEC L-85-T-99 for oxidative stability under an air atmosphere. For glass transition temperatures, consider ASTM E1356.