Abstract: A high isolation microwave module includes a housing floor with mounting surfaces for placing microwave components and housing walls ending in housing wall ends coupled to and projecting from the housing floor. A lid including a lid plate and lid walls ending in lid wall ends projects from the lid plate. The lid walls extend toward the housing floor and the plurality of housing walls extend toward the lid plate but neither the lid wall ends nor the housing wall ends are coupled to the housing floor or lid plate, respectively. A plurality of cavities exist between the adjacent lid walls between the housing and the lid plate and a plurality of irises exist between immediately adjacent housing walls and corresponding lid walls. The irises and cavities act as a multi-section high pass filter to provide attenuation to a microwave signal passing through the module.

Abstract: The invention is concerned with an injection mold for making a plastic impedance measurement module having a generally flat metal grid imbedded in the plastic thereof with a plurality of pairs of electrodes upstanding generally perpendicularly from said grid, one pair into each of a plurality of chambers, said electrodes being uncoated by said plastic. The mold comprises a first mold half having a first generally flat recessed portion defining top surface of a base of the module and a plurality of channels extending from the first portion into the first mold half defining the plurality of chambers and including a plurality of pairs of spaced apart slots extending from the base into the first mold half, one of the pairs of slots extending into each of the chambers for accepting and preventing coating of the electrodes.

Abstract: A multi-chambered module for holding separate samples of nutrient media. A plurality of chambers, with access means into each, is permanently attached to an electrically non-conductive base. Embedded within the base under the chambers is a plurality of electrically conductive leads. Terminal portions at one end of the leads emerge in spaced pairs into each chamber forming electrodes therein. At the other end of the leads terminal portions are exposed for contact with an electrical source. A signal passed through the electrodes in galvanic contact with media permits the impedance thereof to be determined, with changes of impedance directly associated with microorganism growth therein.

Abstract: The invention is concerned with an injection mold for making a plastic impedance measurement module having a generally flat metal grid imbedded in the plastic thereof with a plurality of pairs of electrodes upstanding generally perpendicularly from said grid, one pair into each of a plurality of chambers, said electrodes being uncoated by said plastic.The process comprises placing the grid adjacent a first mold half of an injection mold with the electrodes each within a respective one of a plurality of slots extending into the first mold half, the first mold half having a first generally flat recessed portion defining a top surface of a base of the module and a plurality of channels extending from the first portion into the first mold half defining the plurality of chambers.