| permeability | time rate of water-vapor
transmission through unit area of flat material of unit thickness induced by
unit vapor pressure difference between two specific surfaces, under specified
temperature and humidity conditions. When permeability varies with
psychrometric conditions, the spot or specific permeability defines the
property at a specific condition. Note:
Permeability is a property of a material, but the permeability of a body that
performs like a material may be used. Permeability is the arithmetic product of
permeance and thickness |
Resources 
English RSS