A scanner comprises an electromagnetic wave source; and a detector positioned to measure emissions from the electromagnetic wave source, wherein the electromagnetic wave source comprises a first technology, and the electromagnetic wave source is interchangeable with a second electromagnetic wave source comprising a second technology and/or wherein the detector comprises a first technology, and the detector is interchangeable with a second detector comprising a second technology. Training the scanner to inspect for contaminants includes generating electromagnetic wave emissions at a plurality of combinations of parameters; moving a conveyor belt to expose product having a plurality of contaminants of different sizes to the emissions generated at more than one combination of parameters; recording attenuated emissions that pass through the product at more than one combination of parameters; and selecting a combination of parameters to use when inspecting for the contaminant.