ASTM D4175 Terminology Relating to Petroleum, Petroleum Products, and Lubricants
ullage, n - that volume of a closed system or container which is filled with vapor.
ultimate biodegradation, n - degradation achieved when the test substance is totally utilized by microorganisms resulting in the production of CO2, (and possibly methane in the case of anaerobic biodegradation), water, inorganic compounds, and new microbial cellular constituents (biomass or secretions, or both).
ultimate biodegradation, n - degradation achieved when a material is totally utilized by microorganisms resulting in the production of carbon dioxide (and possibly methane in the case of anaerobic biodegradation), water, inorganic compounds, and new microbial cellular constituents (biomass or secretions or both).
ultimate biodegradation test, n - a test that estimates the extent to which the carbon in a product has been converted to CO2 or methane, either directly, by measuring the production of CO2 or methane, or indirectly, by measuring the consumption of O2.
DISCUSSION - The measurement of new biomass is not attempted.
ultimate biodegradation test, n - a test which estimates the extent to which the carbon in a material is converted to CO2 or methane, either directly by measuring the production of CO2 or methane, or, for aerobic biodegradation, indirectly by measuring the consumption of O2.
DISCUSSION - The measurement of new biomass is usually not attempted.
ultimate tensile strength, n - the highest load attained during a tensile test, converted to unit stress based on the original cross-section area of the tensile test specimen.
unsaponifiable matter, n - in lubricating grease, organic materials, either added or found with fatty materials, which do not react during saponification.
unsulfonated residue, n - in oils, that portion of an oil remaining unsulfonated after treatment with concentrated sulfuric acid.
used oil, n - in petroleum product recycling, oil whose characteristics have changed since being originally manufactured, and which is suitable for recycling.
used oil, n - any oil that has been in a piece of equipment (for example, an engine, gearbox, transformer, or turbine), whether operated or not.
DISCUSSION - In this test method, used oil is from a gasoline engine.
DISCUSSION - Typically, in this test method, the acidity of oxidized hydraulic or steam turbine oils is measured.
DISCUSSION - In this test method, the oil can be any oil that has been used for lubrication of a locomotive diesel engine, whether engaged in railroad or other service.
