The sample flows into a piston based measuring cell via low dead-volume solenoid valves, and is either flushed or isolated for measurement.
Within the measuring cell, resistance thermometers enable the cell and sample temperature to be accurately controlled at the required measurement temperature.
A small defined volume of the sample is held in place by the piston, which is moved to achieve the desired vapour-liquid ratio.
Once equilibrium is established, the absolute pressure inside the cell is converted into actual vapour pressure as required by the test method being emulated.