Magnetic induction tomography: resolution and penetrating power through metal shields

B. Darrera, P. Bartletta, J. Watsonb, F. Renzonia

aDepartment of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, United Kingdom

bAtomic Weapons Establishment, Aldermaston, Reading, RG7 4PR, United Kingdom

Abstract

Magnetic induction tomography (MIT) is a non-contact imaging technique that has applications in security, industry and medicine. The resolution of a MIT system was investigated, as was the system?s ability to image metallic objects through metal shields. The technique employs a driver-coil and sensor-coil. The sample object was imaged via phase-variance measurements between the two coils, due to inductive coupling between the coils and the sample object. The resolution of the MIT system was investigated by producing images of different arrangements of steel ball-bearings. The penetrating power was also demonstrated by imaging a mild-steel bar through a ferromagnetic shield.

Keywords: Magnetic Induction Tomography (MIT); eddy currents; imaging; resolution; alternating magnetic-field; metal shield