Assembly and Method for Measuring a Substance Concentration in a Gaseous Medium by Means of Absorption Spectroscopy

An assembly for measuring a gas concentration by means of absorption spectroscopy in which IR light is guided from a thermal light source through a measuring cell with a gas mixture to be analyzed, and the gas concentration of a gas to be measured that is contained in the gas mixture is determined by measuring an attenuation of the light introduced into the measuring cell caused by absorption by the gas to be measured, wherein the assembly has an optical beam path with a thermal light source that generates IR light, the measuring cell that can be filled or is filled with the gas mixture, and a measuring path for the light generated by the thermal light source, one or more sensors as well as one or more bandpass filters that are upstream from the one or more sensors, wherein the assembly furthermore comprises an evaluation apparatus that is designed to determine the gas concentration to be measured from the attenuation of the IR light in the measuring cell, wherein at least one bandpass filter is designed to transmit within a measuring wavelength range in which the gas to be measured absorbs IR light, and at least one bandpass filter is designed to transmit in a reference wavelength range in which the gas to be measured does not absorb IR light or only absorbs a slight amount in comparison to the measuring wavelength range, wherein the thermal light source is designed as an encapsulated micro-incandescent lamp with a light-generating coil.