Vapor pressure measurement apparatus and method

Abstract From the Canadian patent

Vapor pressure of liquid compositions is measured by a system having a cylinder member in which a reciprocal piston is disposed for movement to contain a sample of liquid and expand the chamber while measuring the pressure in the chamber until a substantially constant pressure is reached with increasing chamber volume. Liquid is circulated from a source such as a petroleum pipeline to the apparatus and continually through the expansible chamber in a retracted position of the piston. When a sample vapor pressure measurement is to be taken, the piston closes off a passage leading to the chamber and displaces liquid out of the chamber until a minimum volume is reached. The movement of the …