Tag closed tester - apparatus for determining the flash point of petroleum liquids having a viscosity below 5.8 centistokes (cSt) at 37.8°C (100°F) and a flash point below 93°C (200°F), under test methods prescribed in ASTM D 56. The test sample is heated in a closed cup at a specified constant rate. A small flame of specified size is introduced in to the cup through a shuttered opening at specified intervals. The lowest temperature at which the vapors above the sample briefly ignite is the flash point. See Pensky-Martens closed tester.