Abstract: Module carrier for receiving a module having a fluid connection for use in a system for water treatment or water monitoring, wherein the module carrier can be reversibly connected to at least one further module carrier to form a module carrier assembly, wherein the module carriers can be connected to one another mechanically and detached from one another, wherein, during the mechanical separation or connection of the module carriers, at least one hydraulic connection between the module carriers can likewise be separated or connected.

Abstract: A fluoride-sensitive electrode having a tubular electrode shaft, a lanthanum fluoride crystal, which closes the end of the electrode shaft, an internal electrolyte sealed between the lanthanum fluoride crystal and a closure in the electrode shaft, and a contact wire which dips into the internal electrolyte, wherein the internal electrolyte has a pH of ?9.0 and a fluoride concentration of ?0.1 M. The invention also includes the method of using the electrode to determine fluoride ion concentration.

Abstract: The present invention concerns a sensor for voltammetric or amperometric measurement of the chlorite concentration (ClO2?) in an solution. In order to provide a chlorite sensor which permits direct measurement of the chlorite concentration without taking samples, separating off accompanying substances or adding chemicals, and which has negligible cross-sensitivity in relation to typical accompanying substances of the chlorite, such as in particular chlorine dioxide (ClO2), chlorate (ClO3?) and hypochlorite (OCl?), it is proposed in accordance with the invention that the sensor has a working electrode of gold.

Abstract: A fluoride-sensitive electrode having a tubular electrode shaft, a lanthanum fluoride crystal, which closes the end of the electrode shaft, an internal electrolyte sealed between the lanthanum fluoride crystal and a closure in the electrode shaft, and a contact wire which dips into the internal electrolyte, wherein the internal electrolyte has a pH of ≧9.0 and a fluoride concentration of ≧0.1 M. The invention also includes the method of using the electrode to determine fluoride ion concentration.