Abstract: The apparatus comprises a circular turntable mounted with its axis of rotation vertical and carrying at respective positions spaced around the peripheral region of the turntable a plurality of specimen containing vials. The turntable is driven by a stepping motor.A rotor assembly is mounted coaxially with the turntable and comprises a central hollow shaft and a number of arms projecting radially from the shaft. A lamp is situated within the hollow shaft and, by virtue of apertures in the wall of the shaft opposite the lamp, produces radial beams of light which are received by respective receivers on the arms of the rotor assembly, after having been directly transmitted through, or scattered by, the specimens in the vials as the rotor assembly rotates. The output signals from the receivers, which depend upon the intensity of received light, enable the specimens to be investigated.Preferably, the apparatus is used in the analysis of blood specimens.

Abstract: In testing for cleanliness a cuvette having translucent wall portions, the cuvette is preferably partially filled with pure water and then a beam of optical radiation is directed at a said wall portion, the intensity of radiation which has passed through the cuvette by direct transmission or by scattering is detected, and the state of cleanliness of the cuvette is determined from a comparison between the detected optical intensity and a criterion indicative of cuvette cleanliness.The invention finds particular application to testing cuvettes for cleanliness which have been washed in a laundry of an automatic blood analysing machine.