Patent ID: 8582103

Claim:
A bulbless spectrometer for measuring the concentration of at least one analyte in a fluid sample, with a light source to generate a light beam, with a photosensor to receive the light beam, and with a measurement length, in which the fluid sample can be placed, in the beam path of the light beam, the measurement length being provided in changeable form, wherein the light source and the photodetector are provided so that they can move relative to each other in order to change the measurement length, and the measurement length is formed between the light source or the photosensor and an optical waveguide arranged in the beam path, and the light source and the optical waveguide and/or the photosensor and the optical waveguide are provided so that they can move relative to each other in order to change the measurement length, wherein the optical waveguide extends into a sleeve, the measurement length is formed between one face of the optical waveguide and an end piece, which seals the sleeve, and the measurement length is changeable by moving the sleeve and the optical waveguide relative to each other.