ASTM E1194-17

5.1 Vapor pressure values can be used to predict volatilization rates 1.1 This test method describes procedures for measuring the vapor pressure of pure liquid or solid compounds. No single technique is able to measure vapor pressures from 1 × 10⁻¹¹ to 100 kPa (approximately 10⁻¹⁰ to 760 torr). The subject of this standard is gas saturation which is capable of measuring vapor pressures from 1 × 10^–11 to 1 kPa (approximately 10^–10 to 10 torr). Other methods, such as isoteniscope and differential scanning calorimetry (DSC) are suitable for measuring vapor pressures above 0.1 kPa An isoteniscope (standard) procedure for measuring vapor pressures of liquids from 1 × 10⁻¹ to 100 kPa (approximately 1 to 760 torr) is available in Test Method D2879. A DSC (standard) procedure for measuring vapor pressures from 2 × 10⁻¹ to 100 kPa (approximately 1 to 760 torr) is available in Test Method E1782. A gas-saturation procedure for measuring vapor pressures from 1 × 10⁻¹¹ to 1 kPa (approximately 10⁻¹⁰ to 10 torr) is presented in this test method. All procedures are subjects of U.S. Environmental Protection Agency Test Guidelines.

1.2 The gas saturation method is very useful for providing vapor pressure data at normal environmental temperatures (–40 to +60°C). At least three temperature values should be studied to allow definition of a vapor pressure-temperature correlation. Values determined should be based on temperature selections such that a measurement is made at 25°C (as recommended by IUPAC) 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.