IP 409: Liquid petroleum products — Vapour pressure — Part 2: Determination of absolute vapour pressure (AVP) between 40 °C and 100 °C

Document options

EI Technical Partners get free access to publications. You will need to Login or Register here

  • Method adopted/last revised: 2008
  • Method reapproved: 2015
  • REF/ISBN: IP409-7250659
  • Status: Current
  • First printed in STM books: May 2019


This European Standard specifies a method for the determination of absolute vapour pressure of liquid petroleum products at elevated temperatures.

The conditions used in the test described in this standard are a vapour to liquid ratio of 3:2 and an initial injection temperature of 37,8 °C or 30,0 °C. The method described is suitable for testing airsaturated samples that exert an air-saturated vapour pressure of between 9 kPa and 500 kPa at temperatures between 40 °C and 100 °C.

This European Standard is applicable to fuels containing oxygenated compounds up to the limits stated in the relevant EC Directive 85/536/EEC [3].

NOTE 1 If a sample injection is into a test chamber which is raised to 37,8 °C and the vapour to liquid ratio is 4:1, the initial measurement corresponds with the measurement in Part 1 of this standard.

NOTE 2 For the purposes of this European Standard, the term % (V/V) is used to represent the volume fraction.

Members Benefits

Are you an EI Member? If yes, register/log in now to ensure you receive free access or discounts to EI publications.

If you are not a Member, why not join today and receive all of the benefits of EI Membership? EI Members are entitled to a 25% discount on most EI publications.