A rotational movement generating apparatus having a platform supported by a support assembly. The device has one receptacle per pipette for a test volume or for a container containing the test volume, and in addition, one weighing cell per receptacle for weighing of the container andor of the test volume. When deployed in a processor-based system, one or more interrupting events may be registered. A color value identifying unit identifies color values of patches in a test chart printed on the chart sheet and color values of patches in the reference chart after the shading correction and the projective transformation.