Abstract: The invention relates to a device for detecting the quality of a liquid in a supply pipe, in particular for detecting the water quality in a water pipe, comprising a flow cell, which has an inlet opening, an outlet opening and at least one receiving device for the arrangement of at least one sensor. The inlet opening and the outlet opening are provided on a base surface of the flow cell intended for connection to the supply pipe, the inlet opening of the flow cell is connected to an intake pipe, the free end of which is intended for arrangement in the supply pipe, said intake pipe being received displaceably in its longitudinal direction in the flow cell or having an adjustable length, and a liquid pump of a flow of the liquid in the supply pipe is connected to the intake pipe.

Abstract: A device for detecting characteristics of a fluid, with a light source for emitting several light beams, of which one of the light beams is a measurement beam, which is provided for a passage through the fluid, and another light beam is a reference beam, which is provided for bypassing the fluid, with a movable cover device arranged downstream of the light source, which cover device is provided for covering the light beams and which is arranged so as to be transferable between a first position releasing the measurement beam and covering reference beam, and a second position covering the measurement beam and releasing the reference beam, and with a light detector arranged downstream of the cover device.

Abstract: Miniaturized spectrometer in the form of a probe for determining ingredients of a gaseous or liquid fluid with a light source and a spectrometer, at least one measurement beam, and at least one reference beam. Light from the light source is optionally fanned out and focused, by at least one optical lens, in an essentially parallel beam. At least one measurement beam is passed through a light transparent window from the probe into the fluid being investigated and through an additional light transparent window back in to the probe, and at least one reference beam is guided in the probe interior. A collecting optics device, comprising at least one lens, diverts the beams to the impingement point of the light guide or the inlet of the spectrometer, and a beam selector in the area of the collecting optics device passes through one of the partial beams and interrupts all the others.