Surface mounted and scanning spatially periodic eddy-current sensor arrays

摘要: Inductive sensors measure the near surface properties of conducting and magnetic material. A sensor may have primary windings with parallel extended winding segments to impose a spatially periodic field in test Those portions be formed by adjacent individual drive coils. Sensing elements provided every other half wavelength connected together series while sensing wavelengths are offset. Certain include circular which create circularly symmetric that is radial direction. Such particularly adapted surround fasteners detect cracks can mounted beneath fastener head. In another sensor, offset along length provide material measurements over different locations when circuit scanned The distance from ends kept constant as space between varied. An image across