Abstract: Disclosed is a measuring arrangement for measuring the total nitrogen bound (TN) in a measuring liquid, comprising: a radiation source emitting UV radiation; a radiation receiver configured to generate a signal that depends on the intensity of radiation impinging on the radiation receiver; a vessel having a first opening and a second opening opposite the first opening; a first window closing the first opening; and a second window closing the second opening. The first and second windows are transparent to the measuring radiation. The measuring radiation emitted by the radiation source propagates along a measuring path which extends from the radiation source through the first window, the vessel, and the second window to the radiation receiver. The measuring arrangement also includes a heating element in thermal contact with the vessel wall.

Abstract: The present disclosure conveys a method for dosing an amount of liquid with a peristaltic pump in an analyzer, wherein the analyzer is configured to determine a concentration of a measurand of a sample, wherein the peristaltic pump includes at least one rotor having at least two rollers, the method comprising the steps: determining the position of at least one roller of the peristaltic pump; moving the rotor of the peristaltic pump to an initial position if it is not already in an initial position; and dosing the amount of liquid to be conveyed by moving the rotor by counting roller passes through a reference position. The present disclosure further discloses an analyzer for implementing the method.