- Permeance
Permeance, in general, is the degree to which a material admits a flow of
matter orenergy .Electromagnetism
In Electromagnetic theory, permeance is the inverse of
reluctance . Permeance is a measure of the quantity offlux for a number of current-turns in magnetic circuit. A magnetic circuit almost acts as though theflux is 'conducted', therefore permeance is larger for large cross sections of a material and smaller for longer lengths.This concept is analogous to that ofelectrical conductance .Measuring Permeance
The equation for permeance is:
frac{Phi}{NI}=Lambda
Where:
Λ=Permeance
Φ=Flux
NI=Current-turns (current x number of coils)
Alternatively, similar to the equation for
electric conductance :frac{muAlpha}{L}=Lambda
Where:
Λ=Permeance μ=Permeability of Material A=Cross Sectional Area L=Length of Circuit
Units of Permeance
The SI unit of permeance is 'webers per ampere-turn' given as Wb A-1.
Materials science
In
Materials science , permeance is the degree to which a material transmits another substance.External articles and references
;Electromagnetism
* [http://orca.phys.uvic.ca/~tatum/elmag/em12.pdf "Properties of Magnetic Materials"] (units of magnetic permeance);Material science
* Bombaru, D., Jutras, R., and Patenaude, A., "Air Permeance of Building Materials". Summary report prepared by, AIR-INS Inc. for Canada Mortgage and Housing Corporation, Ottawa, 1988.
* Don Mills, "The Details of Air Barrier Systems for Houses". Ontario New Home Warranty Program, 1993.
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