Glossary
Pressure standards

Balance de pression ou balance manométrique ; Pressure balance or piston gauge

A standard used to materialize pressure from the basic quantities of the SI system. The principle consists in balancing the force generated by the pressure applied to the cross-section of a piston-cylinder assembly with the force due to the local field of gravity acting on the masses resting on the piston head.

Pressure distortion coefficient; Coefficient de déformation

Coefficient associated with a piston-cylinder assembly representing the variation in cross-section due to pressure, expressed in Pa^–1.

Ensemble piston-cylindre ; Piston-cylinder unit

The main metrological element of the manometric balance, the pressure delivered by the standard is inversely proportional to the cross-section of the piston-cylinder assembly.

Law of propagation of uncertainty; Loi de propagation...