Abstract: A mounting assembly is described which includes first and second housings, a compressible member (e.g. an O-ring) positioned between the two housings, and metering screws for connecting the two housings such that the alignment of the two housings can be adjusted by rotation of the metering screws. Preferably, the O-ring has an elliptical cross-section.

Abstract: A spectrophotometer which accommodates a self-contained sample module. Sample modules are interchangeable and can be readily inserted into, or removed from, the spectrophotometer without tools. Guides in the spectrophotometer assure that the modules are properly aligned when inserted. The module houses the sample(s) to be tested. Sample cell holders may be removed from the module and replaced with other cell holders. When the module is inserted into the spectrophotometer, optical alignment, mechanical alignment, proper electrical connection and software interface are all achieved in one common installation procedure for all sample modules.

Abstract: A reagent vessel and support rack for use in an automated clinical analyzer are disclosed. Characteristic features of the vessel are a membrane covering which is puncturable and preferably self-sealing, and characteristic features of the support rack are a rigid wall and retaining members to hold the vessel in the rack with the membrane against the rigid wall of the rack, thereby providing structural support to the membrane, with holes in the wall to permit access to the membrane and hence to the contents of the receptacle.