ASTM D5763 Standard Test Method for Oxidation and Thermal Stability Characteristics of Gear Oils Using Universal Glassware
1. Scope
1.1 This test method covers the determination of the oxidation characteristics of extreme pressure and non-extreme pressure gear oils and includes the quantitative determination of total sludge, viscosity change, and oil loss.
NOTE 1 - While the round-robin tests used ISO VG 220 extreme pressure gear oils for developing precision data, the test method can be extended to other viscosity grades and to non-extreme pressure gear oils. Refer to Classification D2422 for viscosity grades.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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:
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and the Calculation of Dynamic Viscosity)
D2422 Classification of Industrial Fluid Lubricants by Viscosity System
D2893 Test Method for Oxidation Characteristics of Extreme-Pressure Lubrication Oils
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4871 Guide for Universal Oxidation/Thermal Stability Test Apparatus
E 1 Specification for ASTM Thermometers
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 adherent sludge, n - sludge that is formed on the walls of a container and is not easily removed.
3.1.2 aliquot, n - portion of sample being tested that is a representative portion of the whole.
3.1.3 extreme pressure gear oil, n - gear oil that contains chemical additives, such as sulfur and phosphorus compounds, which produce a protective film on the metal surface to provide anti-scuffing and anti-scoring properties.
3.1.4 filterable sludge, n - sludge that is formed in the oil.
3.1.5 non-extreme pressure gear oil, n - gear oil that contains no extreme pressure additives.
3.1.6 oxidation, n - the process by which oxygen chemically reacts with materials.
3.1.7 sludge, n - in gear oils, a precipitate that sometimes forms as the oil ages or oxidizes.
3.1.8 universal glassware, n - the glassware that is described in the universal oxidation thermal stability test. Refer to Guide D4871.
