Mass and pressure

Unit of mass: kilogram (kg)

The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram.

The international prototype of the kilogram is an artefact made of platinum-iridium; a cylinder made of an alloy for which the mass fraction of platinum is 90 % and the mass fraction of iridium is 10 %. The protoptype is kept at the BIPM under the conditions specified by the 1st CGPM in 1889 when it sanctioned the prototype.


Unit of pressure: pascal (Pa)

Pressure is the amount of force applied perpendicular to the surface of an object per unit area and the for it is p  (or P).

The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N/m2, or kg·m−1·s−2. Pascal is a so-called coherent derived unit in the SI with a special name and symbol.


Calibration services for mass and pressure