Non-dispersive infrared gas analyzer

A non-dispersive infrared gas analyzer for determining concentrations of carbon dioxide and/or carbon monoxide, hydrocarbons, and nitrogen oxides has two measuring cells 4, 6 consecutively traversed by a beam, with an optopneumatic detector 22 for carbon dioxide and an optopneumatic detector 23 for carbon monoxide arranged between them. Detectors 7, 8 for hydrocarbons and nitrogen oxides are arranged on the measuring cell 6 located downstream from detectors 22, 23 in the direction of the beam.