Abstract: One embodiment of the present invention is an analyzer of a multiplicity of gases in a sample gas that includes: (a) an infrared source of infrared radiation; (b) a multiplicity of band-pass filters, including a reference band-pass filter, and an opaque area; (c) a movement mechanism that places the band-pass filters and the opaque area in front of the infrared radiation at predetermined times, and includes a location pickup mechanism; (d) a location pickup mechanism detector that generates movement mechanism timer signals; (e) a sample cell disposed in a path of the infrared radiation through which the sample gas travels; (f) a gas temperature sensor and a pressure transducer that generate temperature and a pressure signals; (g) a detector that detects infrared radiation that has passed through the sample cell and generates detector signals; and (h) a controller that analyzes the movement mechanism timer signals, the detector signals, the temperature signal, and the pressure signal to provide concentrations