1. Vacuum Academy Knowledge Center
  2. Vacuum Physics
  3. Basic terms and concepts in vacuum technology

What is vacuum pressure in mbar?

Pressure p (mbar) of fluids (gases and liquids). (Quantity: pressure; symbol: p; unit of measure: millibar; abbreviation: mbar.)

Pressure p (mbar) of fluids (gases and liquids). (Quantity: pressure; symbol: p; unit of measure:millibar; abbreviation: mbar.) Pressure is defined in DIN Standard 1314 as the quotient of standardized force applied to a surface and the extent of ths surface (force referenced to the surface area). Even though the Torr is no longer used as a unit for measuring pressure (see Section 10), it is nonetheless useful in the interest of “transparency” to mention this pressure unit: 1 Torr is that gas pressure which is able to raise a column of mercury by 1 mm at 0 °C. (Standard atmospheric pressure is 760 Torr or 760 mm Hg.) Pressure p can be more closely defined by way of subscripts: 

  • Absolute pressure pabs
  • Total pressure pt
  • Partial pressure pi
  • Standard pressure pn
  • Ultimate pressure pend
  • Ambient pressure pamb
  • Working pressure pW