ASTM D3934 for flash/no flash test-equilibrium method by a closed-cup apparatus
4. Summary of Test Method
4.1 A specimen in a closed cup of standard design is heated in a suitable liquid bath. After the specimen has been maintained under equilibrium conditions for at least 10 min at the lowest allowable flash point temperature (within a permitted tolerance) of the specification or regulation, it is determined whether the specimen does or does not flash.
5. Significance and Use
5.1 This test method ensures that before the flash test is run the air/vapor space above the specimen has attained a saturation concentration of vapor by using standard closed cups under equilibrium conditions. The saturation concentration of the vapors will be attained at some temperature between that of the liquid and the cooler apparatus lid. However, this temperature will be close to the temperature of the specimen after it has been maintained at the specified temperature for at least a 10-min period. This test method does not provide for the determination of the actual flash point but only whether a specimen does or does not flash at a specified temperature.
