METHOD OF TEST FOR VAPOUR PRESSURE OF PETROLEUM PRODUCTS (REID METHOD)
1.1 This method covers the determination of the
absolute vapour pressure (note 1) of volatile crude oil
and volatile nonviscous petroleum products, except
liquefied petroleum gases (note 2).
NOTE 1. Because the external atmospherIc pressure is counteracted
by the atmospheric pressure initially present in the air
chamber, the ‘Reid vapour pressure’ is approximately the
vapour pressure of the material at 37.8°C(ioO°F),in kilopascais
(kPa = kN/m
2
) (or pounds per square inch absolute).
NOTE 2. For determination of the vapour pressure liquefied
petroleum gases reference should be made to MS1.146’