Automatic chemistry analyzer

An automatic chemistry analyzer is provided having a high throughput and a high reliability. The analyzer uses nephelometric and turbimetric analyzers to analyze a wide variety of parameters within liquid samples typically generated in, for example, a large medical testing laboratory. The machine employs a unique probe and stirring rod assembly mounted at a slight angle with one another using rack and pinion assemblies so that the lower end of the probe and the lower end of the stirring rod are in very close proximity to one another. This feature allows the machine to be used in unusually small reaction cuvettes. The analysis machine also includes an onboard control sample so that the machine can be programmed to periodically calibrate its analyzing equipment during the course of normal operation. The machine also includes a sample station carousel having retainer clips for retaining a sample container rack which is constructed to retain a bar-coded card containing information regarding reagents used in the machine. A bar code reader located proximate to the sample carousel reads the bar-coded reagent information into the controller.