Abstract: An improved luminometer is provided which uses a top loading plate carrier which receives a microtitration plate and uses a mask having an aperture corresponding to each test cell in the plate carrier. When the mask rotates downwardly to cover the microtitration plate, the plate carrier automatically orients the microtitration plate in the X, Y and Z directions. Reagents are added to the individual test cells through the mask aperture. Each reagent injector is extendable and retractable so that liquids can be added below the mask aperture during purging or washing and then the injector retracted. A pump is provided for each injector which is driven by a stepper motor and a rack and pinion connection to a syringe.

Abstract: A vessel for holding at least one test sample to be measured for its fluorescence, wherein the vessel is formed from a material having a native fluorescence, and wherein the vessel is provided with a barrier which blocks penetration or at least reduces the extent of penetration of an exciting light into the vessel's fluorescable material to prevent fluorescent excitation of the vessel or at least reduces the extent to which the vessel is fluorescently excited when exposed to an exciting light during the fluorometric measurement.

Abstract: An electrical jack having at least one socket for receiving an edge connector, a printed circuit board structure having an end portion extending into the socket for reception in the connector upon insertion of the connector into the socket, and switching means normally conditioned to cooperate with a printed circuit on the printed circuit board for electrically connecting a first set of jack terminals to a second set of jack terminals, the switching means extending into the jack's socket for actuation by insertion of the connector into the socket to electrically disconnect the two sets of terminals from each other.

Abstract: An electrical patch cord plug and jack assembly in which the plug is insertable into a selected one of a number of plug-receiving sockets in the jack and has a multiplicity of contact elements arranged in at least one longitudinally extending row for making and breaking various circuit connections in the jack.