FLASH POINT BY CONTINUOUSLY CLOSED CUP TESTER (CCFP): ASTM D6450
EXPLANATION
This test method covers the determination of the flash point of fuel oils, lube oils, solvents, and other liquids by a continuously closed cup tester. The measurement is made on a test specimen of 1 mL. This test method utilizes a closed but unsealed cup with air injected into the test chamber. This test method is suitable for testing samples with a flash point from 10 to 250° C. Flash points below 10° C and above 250° C can be performed; however, the precision has not been determined at these temperatures.
TEST SUMMARY
The lid of the test chamber is regulated to a temperature of at least 18° C below the expected flash point. A 1-mL test specimen is introduced into the sample cup, ensuring that both specimen and cup are at a temperature of at least 18° C below expected flash point, cooling if necessary. The cup is then raised and pressed onto the lid of specified dimensions to form the continuously closed but unsealed test chamber with an overall volume of 4 mL. The lid is heated at a prescribed, constant rate. An arc of defined energy is discharged inside the test chamber at regular intervals. After each ignition, 1.5 mL of air is introduced into the test chamber to provide the necessary oxygen for the next flash test. After each arc, the instantaneous pressure increase above the ambient barometric pressure inside the test chamber is monitored. When the pressure increase exceeds a defined threshold, the temperature at that point is recorded as the uncorrected flash point.
TEST PRECISION
Repeatability: 1.9° C
Reproducibility: 3.1° C
Bias has not been determined.
