1.1 ,This test method covers the use of automated vapor pressure instruments to determine the vapor pressure exerted in vacuum by volatile, liquid petroleum products, hydrocarbons, and hydrocarbon-oxygenate mixtures including ethanol blends up to 85 ,% (volume fraction). This test method is suitable for testing samples with boiling points above 0 ,°,C (32 ,°,F) that exert a vapor pressure between 7 ,kPa and 150 ,kPa (1.0 ,psi and 21 ,psi) at 37.8 ,°,C (100 ,°,F) at a vapor-to-liquid ratio of 4:1. The liquid sample volume size required for analysis is dependent upon the vapor-to-liquid ratio chosen (see Note 1) and the measuring chamber volume capacity of the instrument (see 6.1.1 and Note 5).
Note 1: ,The test method is suitable for the determination of the vapor pressure of volatile, liquid petroleum products at temperatures from 0 ,°,C to 100 ,°,C at vapor to liquid ratios of 4:1 to 1:1 (X = 4 to 1) and pressures up to 500 ,kPa (70 ,psi), but the precision statement (see Section 16) may not be applicable.