Also called magnetic permeability. Electricity. a measure of the change in magnetic induction produced when a magnetic material replaces air, expressed as a coefficient or a set of coefficients that multiply the components of magnetic intensity to give the components of magnetic induction.
Geology. the capability of a porous rock or sediment to permit the flow of fluids through its pore spaces.
Aeronautics. the rate at which gas is lost through the envelope of an aerostat, usually expressed as the number of liters thus diffused in one day through a square meter.
Nautical. the capacity of a space in a vessel to absorb water, measured with reference to its temporary or permanent contents and expressed as a percentage of the total volume of the space.
British Dictionary definitions for non-permeability
the state or quality of being permeable
a measure of the response of a medium to a magnetic field, expressed as the ratio of the magnetic flux density in the medium to the field strength; measured in henries per metre μ See also relative permeability, magnetic constant
(civil engineering) the rate of diffusion of a fluid under pressure through soil
the rate at which gas diffuses through the surface of a balloon or airship, usually expressed in litres per square metre per day
The ability of a substance to allow another substance to pass through it, especially the ability of a porous rock, sediment, or soil to transmit fluid through pores and cracks. Geologic permeability is usually measured in millidarcies. See more at darcy.