Abstract: A system uses a photometer that establishes an optical channel between a light emitter and a light detector. The photometer analyses a specimen while it occupies a well in a tray. A movable platform transports the tray to the optical channel for analysis and removes the tray from the optical channel after analysis. The system calibrates the movable platform to assure proper alignment between the specimen and the photometric apparatus used to analyzed the specimen. The system also calibrates the optical channel without use of an external reference.

Abstract: A holder for storing a specimen tray with a removable cover member includes a frame with oppositely facing first and second access openings The first access opening receives the specimen tray and cover member. The holder supports the specimen tray and cover member within the storage area between a pair of oppositely spaced tray support ledges. The second access opening receives an external member that moves vertically in the storage area to lift the specimen tray from the tray support ledges and that moves horizontally out of the storage area to move the lifted specimen tray from the storage area through the second access opening. The holder pivots the cover member away from the specimen tray to retain the cover member in a tilted orientation within the storage area free of the removed specimen tray until its return.