Testing a cuvette for cleanliness

Apparatus for use in analyzing specimens, said apparatus comprising:

• a carrier having mounted thereon a plurality of cuvettes for containing specimens to be analyzed;
• means for advancing the carrier to cause each cuvette to pass repeatedly through, in succession, a specimen loading region, an analysis region, a cleaning region, and a cleanliness testing region;
• means for introducing specimens into said cuvettes while they are located in the specimen loading region;
• means for performing an analytical test on the specimens in the cuvettes in the analysis region;
• means for cleaning the cuvettes when located in the cleaning region;
• means for effecting a cleanliness test on the cuvettes when they are located in the cleanliness testing region;
• and
• means operative during the continued advancement in said succession of a specified cuvette, which fails the cleanliness test but is retained on said carrier, for inhibiting the effective use of said specific cuvette until it is tested favorably by said testing means following at least one further cleaning of that specific cuvette by said cleaning means.