Pensky–Martens closed-cup test

The sample is heated and stirred at specified rates depending on the material that is being tested.

The ignition source is directed into the cup at regular intervals with simultaneous interruption of stirring.

The different flash point methods depend on the controlled conditions in the laboratory and do not determine an intrinsic property of the material tested.

They are however useful to compare different substances and is therefore widely used in road transportation and environmental safety regulations.

[2] Closed cup testers give lower values for the flashpoint than open-cup testers (typically 5–10 K) and are a better approximation to the temperature at which the vapour pressure reaches the "Lower flammable limit" (LFL).