Patent ID: 7323687

Claim:
An infrared gas analyzer having a sample cell into which a sample gas is distributed, for detecting the concentration of a measuring target component of the sample gas by taking advantage of a variation in an absorption amount of infrared rays having passed through the sample cell, said infrared gas analyzer comprising: a first infrared light source for irradiating the sample cell with infrared rays; a second infrared light source having a response characteristic equal to that of the first infrared light source; a detector for detecting a difference between the first infrared rays emitted from the first infrared light source and passed through the sample cell, and second infrared rays emitted from the second infrared light source and falling directly on the detector; a light source drive controller for synchronously driving the first and second infrared light sources, respectively; and a measurement controller for providing the light source drive controller with instructions for respective drive amounts of the first and second infrared light sources while receiving an output signal from the detector, thereby generating a measurement output corresponding to the concentration of the measuring target component of the sample gas.