Investigation of the significance of the 'body effect' on sensitivity to metallic objects in a walk-through metal detector

Abstract

An investigation has been carried out to determine the extent to which a walk-through metal detection system is affected by the capacitive and inductive coupling between candidates' bodies and the coil array – known as the 'body effect'. In this experiment both small and large items are investigated to determine ratio of the signal contribution from the candidate compared to the object, and a comparison is made between the response of a small object both with and without the candidate. Also an experiment is presented to demonstrate the inductive / capacitive nature of this signal.