A method of searching for sets of data in a very large columnar database is described. The method uses a copper filter mounted on the detector array for tracking the spectral changes. An analog module includes all the analog and mixed-signal components of the mixed-signal core, while a first digital module includes digital components required for functionalparametric verification of the mixed-signal components within the analog module. Items that pass inspection are conveyed to a downstream stacker, then on to item stack conveyors before being moved onto a side transfer conveyor. The corrugations may also be varied to suit the particular heat transfer requirements of the reactions.