Abstract: Dry transparent analytical elements can be used to determine analytes which have been separated by electrically induced migration through a solid medium, e.g. by electrophoresis, or which are intracellular enzymes. The dry transparent element is placed on a plate containing the analytes, and kept there until the analytes have reacted to produce a non-diffusible detectable species solely in the element. The element is removed and the detectable species is evaluated therein. The elements contain a water-insoluble binder material having an interactive composition dispersed therein which reacts with analyte to produce the non-diffusible species. The same electrophoretic plate can be used to successively determine the same or a plurality of analytes since it is not altered or destroyed by contact with the dry element.

Abstract: An humidistat has an element movable in response to ambient relative humidity operatively connected to a core of a linearly variable differential transformer for moving the core. The core is supported within a body portion of the transformer for minimal friction of movement relative to the body portion. The body portion has a primary winding and two secondary windings. An oscillator excites the primary winding to provide output signals from the secondary windings proportioned to movement of the core in the body portion and, therefore, indicative of the relative humidity sensed by the element.