Magnetic permeability
A material's ability to conduct and channel magnetic flux.
Definition
Magnetic permeability, denoted μ, measures how easily a material allows a magnetic flux to become established within it. The higher it is, the more the material “attracts” and channels the flux, and the more efficient the coupling between windings.
The magnetic steels used for transformer cores have a permeability several thousand times greater than that of air. This is why the flux follows the core rather than dispersing. Permeability is not constant, however: it drops sharply as saturation approaches, which degrades operation.
Choosing a high-permeability material (grain-oriented sheets, nickel-iron alloys) reduces the magnetising current and improves efficiency.
The ABL tip
For applications requiring a very low no-load current (instrument transformers, instrumentation), ABL Transfo can use high-permeability materials. Describe your accuracy requirement and we will select the right alloy.
