DEVICE FOR DETERMINING THE CONCENTRATION OF AT LEAST ONE GAS IN A SAMPLE GAS FLOW BY MEANS OF INFRARED ABSORPTION SPECTROSCOPY

摘要

Devices are known for determining the concentration of at least one gas in a sample gas flow by means of infrared absorption spectroscopy, said devices comprising an infrared radiation source (12) the radiation from which can be conducted into a chamber (20) of a gas cell (21), a sample gas flow which can be conducted into the chamber (20) and into the radiation, a detector (22) to which the radiation exiting from the chamber (20) can be conducted and by means of which detector the absorption spectrum of the exiting radiation can be determined, and a heat source (52), via which the sample gas flow is heated to a desired temperature. However, measurement inaccuracies often occur due to temperature gradients within the sample gas flow on the path through the optical measuring cell. In order to prevent these inaccuracies, the present application proposes that the heat source (52) is arranged within a thermal insulation (74) of the gas cell (21), wherein a sample gas channel (36) heated by the heat source (52) is arranged within the thermal insulation (74) upstream of an outlet (62) into the chamber (20).