3. Terminology
3.1 Definitions
3.1.1 Flash point - the lowest temperature corrected to a pressure of 101.3 kPa (760 mm Hg) at which application of an ignition source causes the vapors of a specimen of the sample to ignite under specified conditions of test.
3.1.1.1 Discussion - The specimen is deemed to have flashed when a flame appears and instantaneously propagates itself over the entire surface of the fluid.
3.1.1.2 Discussion - When the ignition source is a test flame, the application of the test flame may cause a blue halo or an enlarged flame prior to the actual flash point. This is not a flash and should be ignored.
3.2 Definitions of Terms Specific to This Standard
3.2.1 dynamic (non-equilibrium) - in this type of flash point apparatus, the condition of the vapor above the specimen and the specimen are not at the same temperature at the time that the ignition source is applied.
3.2.1.1 Discussion - This is primarily caused by the heating of the specimen at the constant prescribed rate with the vapor temperature lagging behind the specimen temperature. The resultant flash point temperature is generally within the reproducibility of the test method.
3.2.2 equilibrium - in that type of flash point apparatus or test method, the vapor above the specimen and the specimen are at the same temperature at the time the ignition source is applied.
3.2.2.1 Discussion - This condition may not be fully achieved in practice, since the temperature is not uniform throughout the specimen and the test cover and shutter are generally cooler.
