IEVref: 221-03-17 ID: Language: en Status: Standard Term: effective permeability Synonym1: Synonym2: Synonym3: Symbol: µe Definition: for a magnetic circuit constructed of different materials or non-homogeneous materials or both, the permeability of a hypothetical homogeneous material which, when used to construct a circuit of identical dimensions, would provide the same reluctance NOTE 1 – Where the different materials are in series along the magnetic path and the permeability can be assumed constant over any cross-section, the following equation is applicable: $\frac{1}{{\mu }_{\text{e}}}\sum \frac{l}{A}=\sum \frac{l}{{\mu }_{\text{r}}A}$ where l is the length, measured along the magnetic path, of each part of the core of uniform cross-section A and homogeneous permeability µr. NOTE 2 – The effective permeability is used particularly in relation to cores having (air) gaps and it is usually restricted to cases where the leakage flux is relatively small. Publication date: 1990-10 Source: Replaces: Internal notes: 2016-01-06: "may" corrected to "can". JGO 2017-06-02: Cleanup - Remove Attached Image 221-03-17.gif CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: