ASTM D5190 Vapor Pressure of Petroleum Products (Automatic Method)
ASTM D5190 Standard Test Method for Vapor Pressure of Petroleum Products (Automatic Method)
4. Summary of Test Method
4.1 The chilled sample cup of the automatic vapor pressure instrument is filled with chilled sample and is coupled to the instrument inlet fitting. The sample is then automatically forced from the sample chamber to the expansion chamber where it is held until thermal equilibrium at 37.8°C (100°F) is reached. In this process the sample is expanded to five times its volume (4:1 vapor-to-liquid ratio). The vapor pressure is measured by a pressure transducer.
4.2 The measured vapor pressure is automatically converted to a DVPE value by the instrument. A correction to this value is necessary to account for the observed bias between the test result and that obtained by Test Method D4953.
5. Significance and Use
5.1 Vapor pressure is an important physical property of volatile liquids.
5.2 The vapor pressure of gasoline and gasoline-oxygenate blends is regulated by various government agencies.
5.3 Specifications for volatile petroleum products generally include vapor pressure limits to ensure products of suitable volatility performance.
5.4 This test method is more precise than Test Method D4953.
