Abstract
This thesis investigates generic properties of inductive metal detector signals. The responses of metals are modelled, and the linear basis of these responses is analysed numerically using singular value decomposition. It is found that although the space of metal responses is theoretically high dimensional, the effective dimensionality is actually very low, and this has practical relevance in applications of processing and compressing metal detector signal data. Power transfer in metal detectors is investigated via circuit models, and key determining factors for the signal-to-noise-ratio of inductive detectors are elucidated. A design for a pulse induction device is presented, with emphasis on the capability of outputting high quality data to a computer for analysis. The linear response of the completed system is characterised, as well as the noise present in the experimental set-up. A few real metal targets are tested and their responses are explored, with results in broad agreement with the linear theory.