Chemistry analyzer

摘要

A carousel receives a plurality of removable reagent containers, a turntable receives a plurality of sample fluid containers and a rotatable cuvette assembly holds an annular array of reaction and test cuvettes. A robotic arm carrying a fluid transfer needle coupled to a pair of syringes picks up one or more reagents and sample fluid for deposit into a cuvette. As the arm moves the needle tip exterior is washed and contaminants sent to a waste collector. At the end of a test cycle, the needle core is flushed and cleaned. A colorimetry photometric test is performed on the reacted fluids in each cuvette by a system employing ten interference filters, corresponding diode detectors and amplifiers employing two identical multiplexers providing identical filtered signals for logarithmic calculation of absorbance. The calculation subtracts a noise base level signal of one filter output from one multiplexer from a peak level signal produced by a second filter output from the other multiplexer for each component under test. A reciprocating plunger aspirates and cleans each cuvette at a single cleaning station employing multiple reciprocating motions. The photometric test is completed on all cuvettes in a single test cycle which are subsequently cleaned for the next test sequence.