Pensky-Martens closed cup

In the Pensky-Martens closed cup flash point test, a brass test cup is filled with specimen and fitted with a cover. The sample is heated and stirred at specified rates depending on whether it is a light or heavy oil being tested. An ignition source is directed into the cup at regular intervals with simultaneous interruption of stirring until a flash that spreads throughout the inside of the cup is seen. The corresponding temperature is the flash point temperature.