| 摘要 |
<p>True vapor pressure of liquid compositions, particularly multi-component compositions, is measured by a piston and cylinder apparatus (14) defining an expansible chamber (84) in which a sample of liquid is trapped, the chamber (84) is expanded in multiple steps and multiple pressure and temperature measurements are taken at each expansion over a period of time. A resultant pressure at each expansion is determined from multiple measurements using the least squares method of approximation and the plural resultant pressure values are extrapolated to determine true vapor pressure using a straight-line approximation. The apparatus is adapted to continuously measure vapor pressure of a process stream by sampling a slipstream of liquid which is maintained at a constant temperature. The apparatus is mounted horizontally to minimize liquid depth and increase the rate of bubble formation during expansion of the chamber.</p> |
