Barrer

Barrer is a non-SI unit of gas permeability (specifically, [gas] permeability) used in the membrane technology and contact lens industry. It is named after Richard Barrer.

Definition

${\rm {{1}\ barrer={10^{-10}}{\frac {cm_{STP}^{3}\cdot cm}{cm^{2}\cdot s\cdot cmHg}}}}$

Here the 'cm³_STP' is standard cubic centimeter, which is a unit of amount of [gas] rather than a unit of volume. It represents the amount of gas molecules or moles that would occupy one cubic centimeter at standard temperature and pressure, as calculated via the ideal gas law.
The cm corresponds in the permeability equations to the thickness of the material whose permeability is being evaluated, the cm³_STPcm⁻²s⁻¹ to the flux of gas through the material, and the cmHg to the pressure drop across the material. That is, it measures the rate of fluid flow passing through an area of material with a thickness driven by a given pressure. See Darcy's Law.

This article is issued from Wikipedia - version of the 11/21/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.