Apparatus and Methods for Measuring Permeability and Conductivity in Materials using Multiple Vavenumber Magnetic Interrogati

Author:  James R. Melcher
Source:  US Patent 5,015,951
Doc ID:  1991092
Year of Publication:  1991
Abstract:  
Devices and analytical techniques are disclosed for measuring spatial profiles of complex premeability and conductivity of a material by multiple wavenumber interrogations. Coil array structures are disclosed which define a number of different fundamental wavelengths (or wavenumbers). Spatially periodic interrogation signals (of temporal frequency "w") from the coil array structures are attenuated by varying degrees in the material undergoing analysis, depending on the wavenumber ("k"), therby permitting the derivation of composite complex permeability/conductivity profile.