4. Summary of Test Method
4.1 The specimen is placed in the cup of the tester and, with the lid closed, heated at a slow constant rate. An ignition source is directed into the cup at regular intervals. The flash point is taken as the lowest temperature at which application of the ignition source causes the vapor above the specimen to ignite.
5. Significance and Use
5.1 Flash point measures the tendency of the specimen to form a flammable mixture with air under controlled laboratory conditions. It is only one of a number of properties that shall be considered in assessing the overall flammability hazard of a material.
5.2 Flash point is used in shipping and safety regulations to define flammable and combustible materials. One should consult the particular regulation involved for precise definitions of these classes.
5.3 Flash point can indicate the possible presence of highly volatile and flammable materials in a relatively nonvolatile or nonflammable material. For example, an abnormally low flash point on a sample of kerosene can indicate gasoline contamination.
6. Apparatus (Manual Instrument)
6.1 Tag Closed Tester - The apparatus is shown in Fig. 1 and described in detail in Annex A1.
6.2 Shield - A shield 460 mm (18 in.) square and 610 mm (24 in.) high, open in front, is recommended.
6.3 Temperature Measuring Device - A liquid-in-glass thermometer, as prescribed in Table 1, or an electronic temperature measuring device such as a resistance device or thermocouple. The device shall exhibit the same temperature response as the liquid-in-glass thermometer.
NOTE 2 - Whenever thermometers complying with ASTM requirements are not available, thermometers complying with the requirements for The Institute of Petroleum thermometer IP 15C PM-Low can be used.
