A linking mechanism used in a key switch assembly is disclosed to include a first link, which is shaped like an open frame, and a second link, which is receivable within the first link. The image sensor includes an output bus, a two dimensional array of pixel sensors that receives light from a layer of scintillation material and a controller. Further, a dehydrating agent is added during saponification reaction in the preparation of a sample for analysis, whereby a deviation of a measured value can be reduced.