A computer-implemented method for calibrating a photometer in an in-vitro diagnostics analyzer includes generating a cuvette map of a reaction ring identifying a plurality of cuvette locations. The cuvette map is used to identify a plurality of reference measurement areas between the plurality of cuvette locations. A plurality of reference measurements are acquired in the reference measurement areas using the photometer. The photometer is automatically calibrated based on a comparison of the reference measurements to a predetermined standard setup of the photometer.