ABEL TEST, the close-test process of determining the flash point of petroleum, invented by Sir Frederick Abel and embodied in the British Petroleum Act of 1879. The test is employed to ascertain whether a sample of petroleum may be safely used at a given temperature.
The Abel apparatus simply raises the temperature of the sample under test until the resultant combination of oil vapour and air forms an explosive mixture and causes a flash. The minimum limit of flash-point under British law is 73°, and most civilized countries have provided a similar test of inflammability. (See PETROLEUM.)