Effect of Shielding Conductivity on Magnetic Induction Tomographic Security Imagery

Recently, there has been a rapid rise in experiential research investigating the potential of exploiting magnetic induction tomographic techniques to improve security, develop industry, and enhance medicine. This investigation explored the functionality of a fully automated magnetic imaging system able to capture 2-D images of featured metallic objects in unshielded and beneath conductively shielded configurations. Images were captured using a programmable x-y stage that moved objects relative to, and when magnetically coupled with, a stationary induction sensor coil; thus, position-resolved measurements of variations in sensor inductance (L) clearly defined the features of conductive objects and distinguished different material types. This investigation concentrated first on exploring the system's ability to distinguish different metals from images that represented proportional conductivity maps, and second, on the effects that a range of shielding conductivity materials had on resultant image quality and resolution. This investigation has provided a greater understanding when assessing potential capability improvements that magnetic induction tomographic techniques could offer a security and/or industrial application.