Abstract: Disclosed is a process photometer arrangement (10) with a photometric cuvette unit (20) comprising a cuvette body (24) defining a cuvette cavity (25) and a combined sample inlet/outlet opening (34), a photometer light inlet window (60) and a photometer light outlet window (62). The cuvette body (24) is movably supported by a cuvette body support element (88) and the cuvette unit (20) is provided with a cuvette vibration device (80) for vibrating the cuvette body (24) to thereby quickly and homogenously mix a liquid sample volume (31) within the cuvette cavity (25) without any separate mixing element within the cuvette cavity. This allows a short mixing action within a microfluidic cuvette.

Abstract: A method for the determination of a plausibility of a measurement result of a determination of an ammonium content of an aqueous sample. The method includes providing a blue indole dye mixture of the aqueous sample, determining a first extinction value of the blue indole dye mixture in a first absorption region, determining a second extinction value of the blue indole dye mixture in a second absorption region, dividing the first extinction value by the second extinction value so as to obtain a quotient, and determining the measurement result to not be plausible if the quotient ? 1.1.

Abstract: The invention refers to an optical measurement apparatus (10) with an optical device (18,20,22) and a liquid sample vessel (12) for measuring an optical parameter of a liquid sample (13) in the liquid sample vessel (12), comprising a drying circuit circulating drying air for venting the sample vessel (12), wherein the drying circuit comprises a mechanical water stop means (100) in the course of the drying circuit, the water stop means (100) comprising a conduit body (102) with a water-absorbing swelling element (120) arranged within the conduit body (102). The water stop means is simple and inexpensive and reliably protects all elements downstream of the water stop means from a water ingress upstream of the water stop means.

Abstract: A nephelometric turbidimeter for measuring a turbidity of a liquid sample in a transparent sample cuvette. The nephelometric turbidimeter includes a cuvette chamber housing with a cuvette chamber having the transparent sample cuvette arranged therein, and a drying apparatus. The drying apparatus includes a cuvette chamber inlet opening which vents the cuvette chamber, a cuvette chamber outlet opening which de-vents the cuvette chamber, an air circulator which circulates air from the cuvette chamber outlet opening to the cuvette chamber inlet opening, and a drying body. The drying body is provided as a container of a hygroscopic agent defined by a drying substance which is arranged in a drying path between the cuvette chamber outlet opening and the cuvette chamber inlet opening so that air flows through the drying body.

Abstract: A nephelometric turbidimeter for measuring a turbidity of a liquid sample in a transparent sample cuvette. The nephelometric turbidimeter includes a cuvette chamber housing with a cuvette chamber having the transparent sample cuvette arranged therein, and a drying apparatus. The drying apparatus includes a cuvette chamber inlet opening which vents the cuvette chamber, a cuvette chamber outlet opening which de-vents the cuvette chamber, an air circulator which circulates air from the cuvette chamber outlet opening to the cuvette chamber inlet opening, and a drying body. The drying body is provided as a container of a hygroscopic agent defined by a drying substance which is arranged in a drying path between the cuvette chamber outlet opening and the cuvette chamber inlet opening so that air flows through the drying body.