permeability number

permeability number

[‚pər·mē·ə′bil·əd·ē ‚nəm·bər]
(engineering)
A numbered value assigned to molding materials indicating the relative ease of passage of gases through them.
References in periodicals archive ?
Procedure - The permeability number, which has no units, is determined by the rate of flow of air, under standard pressure, through a 2 x 2-in.
Permeability can be measured with commercially available equipment and is usually specified as a permeability number.
In addition, Mercury Marine determined that these "precision" sands should have an AFS GFN of 25-33, with an AFS permeability number of 450-500.