GB/T 21789-2008 The Abel closed cup method is used to determine the flash point of petroleum products and Miscellaneous liquids. This standard is applicable to a variety of liquid samples. The principle is to heat up the liquid in the closed cup, introduce an ignition source regularly, and determine the flash point according to the occurrence of flash fire phenomenon. The standard specifies the specifications and accuracy of the required instruments, such as the Abel closed cup flash point tester, and details the sample preparation steps, including sample collection, temperature equilibrate, etc. Clarify the heating rate, ignition operation and other experimental procedures. According to this standard, the liquid flash point can be accurately determined, providing an important safety index basis for the safe storage, transportation and use of liquids.