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Pressure

Working Group 3.33

Realisation of the pressure scale

On the basis of the laws of physics, standard devices used for the realisation of the pressure scale allow pressure values to be determined from:

  • measured values of SI base units such as length, mass, temperature;
  • values of material constants, such as density, expansion coefficients;
  • natural constants such as acceleration due to local gravity;
  • measured values of influencing quantities such as air pressure and ambient temperature.

Standard devices for the realisation of the pressure scale are validated within the scope of international comparisons between national metrology institutes (Opens external link in new windowinfo).

Survey of the measuring ranges of standard instruments

Standard device

Measuring range

Pressure mode

from

to

pabs

pe

Δp

Mercury precision manometer

180 kPa

+

+

+

Diving bell manometer

4 kPa

 

+

+

Pressure balance with digital display

7 kPa

+

+

 

Pressure balance

5 kPa

7 MPa
80 MPa

+

+
+

 

Twin pressure balance for differential pressure measurement in gases

80 MPa
pline: 80 MPa

 

 

+

Liquid column for differential pressure measurement in gases; manometric liquid: Water

10 kPa
pline: 14 MPa

 

 

+

Pressure balance; oil operated

0,2 MPa

1 GPa

 

+

 

Manganin-Manometer

1,4 GPa

 

+

 

 

The international admitted measurements are published in the database of International Bureau of Weights and Measures (Opens external link in new windowBIPM).