Glossary
Very low pressure gaz. Installation sizing

Pressure ; pressure

Vacuum pressure is the force exerted by a gas on the area of a real surface divided by this area.

Flow-volume ; volume flow rate

Volume flow is the volume of a gas at a given pressure and temperature that is displaced per unit time.

Flow ; throughput

Gas flow is the product of pressure and volume flow.

Conductance ; conductance

Conductance is the flow divided by the difference in mean pressures at both sides of a pipe or orifice.

Desorption ; desorption

Desorption refers to the natural release of gas molecules that have been sorbed by a material. They may be deposited in successive layers on the surface (adsorbed), or come from within the material (absorbed).