5.6 DETERMINATION OF FLASH POINT FOR BITUMEN

STANDARD

  • IS: 1209—1978 (3).

DEFINITION
Flash Point

  • The flashpoint of a material is the lowest temperature at which the application of test flame causes
    the vapors from the material momentarily catch fire in the form of a flash under specified
    conditions of the test.

APPARATUS

  • Pensky Martens Closed Tester consisting of 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.
  • High range thermometer 90 to 370°C and capable of reading up to 2 °C.

PROCEDURE

  • 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, high or low range, as required.
  • 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 5 to
    6°C per minute.
  • Start stirring at a rate of 60 revolutions per minute,
  • Apply the test flame at each temperature reading, which is a multiple of 1°C up to 104°C.
  • For the temperature range above 104°C, apply the test flame at each temperature reading, which is a multiple of 2°C.
  • Apply initial test flame at least 17°C below the expected flashpoint.
  • Apply the test flame by operating the device controlling the shutter and 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.

REPORT
Flash Point

  • The flashpoint shall be taken as the temperature read on the thermometer at the time of the flame application that causes a distinct flash in the interior of the cup.

PRECISION

  • The duplicate test results should not differ by more than the values given below
    Flash Point Repeatability Reproducibility
    104°C and below  8°c 11°c
    Above 104°C 8°c 14°c

PRECAUTIONS

  • 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.

Leave a Comment

Your email address will not be published. Required fields are marked *