Patent ID: 7910061

Claim:
A colorimetric absorbance measurement apparatus comprising: a light source which produces a measuring light beam along an optical axis; a plurality of cuvettes which are conveyed and halted such that the cuvettes intersect sequentially the optical axis of the measuring light beam produced by said light source, wherein at least one cuvette contains a sample and is conveyed to the optical axis of said measuring light beam during a measurement, and wherein said cuvettes are circularly disposed in a holder in a first plane, said first plane being substantially perpendicular to the optical axis of said measuring light beam; a first motor for conveying said cuvettes by rotating the cuvettes around a first axis which is substantially parallel to the optical axis of said measuring light beam, thereby causing each of said cuvettes to move to the optical axis of the measuring light beam sequentially; a filter assembly on which a plurality of filters are arranged in a circular pattern, each of the filters passing only such light components that have wavelengths falling within a wavelength range specific to said each of said filters, said wavelength range specific to said each of said filters having a center wavelength specific to said each of said filters; a second motor for rotating said filter assembly about its central axis which is substantially parallel to the optical axis of said measuring light beam, so as to rotate the filter assembly in a second plane which is substantially perpendicular to the optical axis of said measuring light beam, thereby causing the multiple filters to sequentially intersect the optical axis of said measuring light beam; a motor driver, said motor driver driving said second motor such that said filter assembly continuously rotates at a speed; a photoelectric converter performing photoelectric conversion in which light from said measuring light beam, which has passed through a selected one of the multiple filters when said filter assembly rotates at said speed and through said at least one cuvette, is converted into an electric signal; a signal processor for processing an output signal of the photoelectric converter for measuring absorbance of a fluid including said sample in said at least one cuvette; and a controller controlling said signal processor to perform the signal processing in synchronism with the timing at which the selected one of the multiple filters is positioned on the optical axis of the measuring light beam, wherein said controller synchronizes the signal processes with the rotation of said filter assembly based on a motor drive signal fed from said motor driver, and wherein during a measurement, one of said filters, one of said cuvettes, and said photoelectric converter are on the optical axis of the measuring light beam, and the cuvette which is on the optical axis of the measuring light beam is located between said filter assembly and said photoelectric converter along the optical axis of the measuring light beam.