Abstract: A method of referencing in optical absorption spectroscopy using broadband light sources for determining the concentration of substances in gaseous or fluid media through and to a device for measuring the concentration of substances in gaseous or fluid media within the measurement path of a measurement cell using absorption spectroscopy of light emitted from broadband light sources via light guiding optics.

Abstract: A method of referencing in optical absorption spectroscopy using broadband light sources for determining the concentration of substances in gaseous or fluid media through and to a device for measuring the concentration of substances in gaseous or fluid media within the measurement path of a measurement cell using absorption spectroscopy of light emitted from broadband light sources via light guiding optics.

Abstract: The invention relates to a method and to a device for using partially non-stabilized broadband light sources to accurately measure partially broadband-absorbing substances using referencing measuring cells. In order to create a low-cost, high-resolution, and at the same time fast spectrographic device for measuring concentrations of substances in fluid or gaseous media that is also suitable for harsh environments, the light radiated by the broadband light sources (1) through light guiding optical systems is fed through the measuring section of the self-referencing measuring cell (20, 30, 40) or only partially through a measuring cell (10) to a measurement detector (photoreceptor 11) and partially through a reference path (optical waveguide 8) to a reference detector (photoreceptor 15), and a mode coupler (5, 9, 14) is associated with each optical waveguide (2, 4, 7, 8) in order to homogenize the radiation characteristic of the broadband light sources (1), which varies over time and space.