- The flashpoint of a material is the lowest temperature at which the application of test flame causes the vapours from the material momentarily catch fife in the form of a flash under specified conditions of the test,
- Pensky Martens Closed Tester consisting of a cup, lid, stirring device cover shutter, and flame exposure device, etc.
- Low range Thermometer -7 to +110°C and capable of reading up to 0.5°C.
- Clean and dry all parts of the cup and its accessories thoroughly before the test.
- Take particular care to avoid the presence of any solvent used to clean the apparatus.
- Fill the cup with the material to be tested up to the level indicated by the filling mark.
- Place the lid on the cup and set the latter in the stove.
- Take care that the locating devices are properly engaged.
- Insert the thermometer.
- Completely fill the air space between the cup and the interior of the air bath with water at the temperature of the tester and material.
- Light and adjust the test flame so that it is of the size of a bead of 4mm in diameter.
- Apply heat at such a rate that the temperature recorded by the thermometer increases between 1 to 1.5°C per minute.
- Start stirring at a rate of 70 to 80 revolutions per minute.
- Apply initial test flame at least 17°C below the expected flash point.
- Apply the test flame by operating the device controlling the shutter arid test flame burner so that the flame is lowered in 0.50 seconds, left in its lowered position for one second, and quickly raised to its high position.
- Discontinue stirring during the application of test flame.
- Carefully observe the surface of the material during heating.
- The flash point shall be taken as the temperature read on the thermometer at the time of the flame the application that causes a distinct flash in the interior of the cup.
The duplicate test results should not differ by more than the values given below
- Do not confuse with the bluish halo flame that some times surrounds the test flame as the true flash.
- Take care to shield the apparatus from the draughts.
DETERMINATION OF FLASH AND FIRE POINT FOR BITUMEN
|Description||Units||Test 1||Test 2||Test 3|
|Average Flash Point||°C|