ASTM D5482 Standard Test Method for Vapor Pressure of Petroleum Products (Mini Method - Atmospheric)
4. Summary of Test Method
4.1 A known volume of chilled, air-saturated sample is introduced into a thermostatically controlled test chamber, the internal volume of which is five times that of the total test specimen introduced into the chamber. The test chamber is at atmospheric pressure prior to introduction of the sample. After introduction of the sample into the test chamber, the test specimen is allowed to reach thermal equilibrium at the test temperature, 37.8°C (100°F). The resulting rise in pressure in the chamber is measured using a pressure transducer sensor and indicator.
4.2 The measured total vapor pressure is converted to a DVPE by use of a correlation equation (see 13.2).
5. Significance and Use
5.1 Vapor pressure is an important physical property of volatile liquids.
5.2 Vapor pressure is critically important for both automotive and aviation gasolines, affecting starting, warm-up, and tendency to vapor lock with high operating temperatures or high altitudes. Maximum vapor pressure limits for gasoline are legally mandated in some areas as a measure of air pollution control.
