Abstract: A method for determining an analyte in a water sample with a mobile water analyzing system having a basic unit and a test element insertable in the basic unit, the method comprising providing the test element and the basic unit. The test element is inserted into a test element receptacle of the basic unit. The water sample is transported forward from an inlet opening to a measuring section of the test element. A first analyzing of the water sample is performed in the measuring section with an analyzer of the basic unit. The water sample is transported forward from the measuring section to the first reagent section of the test element. The water sample is transported backward from the first reagent section to the measuring section of the test element. A second analyzing of the water sample is performed in the measuring section with the analyzer of the basic unit.

Abstract: A wastewater analysis sensor cartridge (10) according to the invention is intended to be used only once. It has a liquid-tight housing (20), which contains at least one electrochemical sensor element (30, 32) and at least one reference element (56). Furthermore, the housing (20) contains a sensor element electrolyte tank (40,42) and a reference element electrolyte tank (44). The ion-sensitive membranes (31, 33) of the sensor elements (30, 32) and the housing (20) consist of plastic.

Abstract: An immersion probe for water analysis includes at least two sensors configured to determine different water parameters, a sensor module receiving portion with at least two sensor-module plug-in positions, and at least two sensor modules. The at least two sensor-module plug-in positions are configured to be substantially physically and electrically similar. Each of the at least two sensor modules respectively comprise a sensor and are disposed in a respective sensor-module plug-in position.

Abstract: Feed devices for liquid samples serve to convey liquid samples, for example to convey a liquid sample from waste water in a waste water treatment plant so as to monitor the treatment process. Known feed devices feed continuously at relatively low speeds. Films may accrete in the feed line that hinder the feeding and may react with the liquid sample. Therefore, the feed line must be cleaned frequently. In view of this, it is the object of the invention to improve the handling and the maintenance of a feed device for liquid samples. According to the invention, this object is solved by the fact that the feed pump (16) feeds in a pulse-like manner and the feed pump (16) as well as the feed line (18) are configured such that the expansion volume of the feed line (18) during the feed pulse is at most 50% of the pulse volume. Thereby, the feed line is cleaned and kept free of accretions.

Abstract: An immersion probe for water analysis includes at least one electrode configured to detect an analyte in water, a probe head with a probe head end side on which the at least one electrode is disposed, and a separate protective cap attached to the probe head so as to be removable in a distal direction. The separate protective cap includes a protective cap end side with an electrode opening and an air discharge nozzle. The air discharge nozzle is configured so as to cause air exiting the air discharge nozzle to sweep over the at least one electrode.

Abstract: Gas-selective electrodes in liquid analyzing devices have a characteristic curve K with a linear portion L and a non-linear portion NL. In the non-linear portion NL, the characteristic previously could only be estimated so that determinations of the concentration were rather inexact. According to the present application, the electrode is rinsed with an acid and the zero point voltage UN at the electrode is determined during the rinsing. Using the zero point voltage UN, the non-linear portion NL of the characteristic K is determined with high precision so that even low concentrations c can be determined with great accuracy.

Abstract: A method for determining a condition indicator of a water analysis apparatus includes determining a respective parameter value for each of at least two different technical parameters of the water analysis apparatus. A respective deviation value of each of the parameter values is determined with respect to an associated respective parameter reference value for each of the technical parameters. A respective deviation relevance value from each of the deviation values is determined using a respective parameter-specific deviation relevance function for each of the parameter values, the parameter-specific deviation relevance functions being different from each other. Using an indicator function, a condition indicator is calculated from the determined deviation relevance values.

Abstract: A method for automatically determining the concentration of nitrite in a liquid sample includes: determination of the extinction of the liquid sample at a wavelength ? of 150-250 nm, addition of a nitrite reducing agent to the liquid sample, determination of the extinction of the reduced liquid sample at a wavelength ? of 150-250 nm, and determination of the nitrite concentration from the difference between the concentration values obtained from the extinctions of the non-reduced and the reduced liquid samples.

Abstract: The invention relates to a waste water immersion probe (10) comprising a liquid-tight housing (11), a sensor (18) which is disposed in the housing (11) and a sensor window (20) formed on the housing (11). A wiper element (22) for cleaning the sensor window (20) is arranged on the outside of the sensor window (20), and the wiper element (22) is driven by a drive motor (24) which is arranged essentially in the housing (11). The housing is devoid of openings. A magnetic element (36, 37) is associated with the drive motor (24) and a magnetic element (34, 35) is associated with the wiper element (22) in such a manner that the magnetic drive motor element (36, 37) produces a magnetic field which transverses the housing wall and transmits a drive torque to the wiper element (22) without a shaft.

Abstract: The invention relates to a sedimentation plant comprising a sedimentation basin (12), a cleaner beam (18) and an ultrasonic sludge level probe (30) which is suspended in the sedimentation basin (12). The cleaner beam (18) collides with the sludge level probe (30) in a regular manner ensuring that the sludge level probe (30) is displaced from the vertical spatial position and that the distance measuring values supplied thereby are no longer required for evaluating the height (h) of the sludge level (40). A positional sensor (34) is associated with the ultrasonic measuring head (32), which determines the spatial position of the ultrasonic measuring head (32). As a result, an error position of the ultrasonic measuring head (32) can be determined and the distance measuring values supplied by the ultrasonic measuring head (32) when in the error position are suppressed when the height (h) of the sludge level (40) is determined.

Abstract: A wastewater analysis sensor cartridge (10) according to the invention is intended to be used only once. It has a liquid-tight housing (20), which contains at least one electrochemical sensor element (30, 32) and at least one reference element (56). Furthermore, the housing (20) contains a sensor element electrolyte tank (40,42) and a reference element electrolyte tank (44). The ion-sensitive membranes (31, 33) of the sensor elements (30, 32) and the housing (20) consist of plastic.

Abstract: The present invention relates to a method for determining the organically bound carbon (TOC) in an apparatus which has at least one reaction zone (2) and at least one detection zone (3), a) the sample being placed into the reaction zone (2) of the apparatus (1), b) the apparatus being sealed, c) the organically bound carbon being converted into gaseous carbon dioxide by means of physical, chemical, biochemical or microbiological methods, d) the gaseous carbon dioxide being transferred to the detection vessel (3, 3a) and e) the carbon dioxide content being determined by means of measurement methods known per se on the basis of the colour change of the indicator, after step a), the inorganic carbon being converted into carbon dioxide and expelled.