Patent ID: 6218665
Filing Date: 2001-04-17
Classification: G01N

Abstract:
A gas analyzer comprising:a light source for intermittently generating infrared radiation;first signal outputting means having a first photoconductive infrared detector for outputting an electric signal which corresponds to a resistance of said first photoconductive infrared detector which is irradiated with the infrared radiation from said light source via a gas to be measured;second signal outputting means having a second photoconductive infrared detector for outputting an electric signal which corresponds to a resistance of said second photoconductive infrared detector which is irradiated with the infrared radiation from said light source via said gas to be measured;a gas cell filled with a gas that is the same as the gas to be measured, said gas cell being located between said light source and one of said first signal outputting means and said second signal outputting means such that infrared radiation passes through said gas cell;AC component detecting means for detecting an AC component from the output signal of said first and second signal outputting means;DC component detecting means for detecting a DC component from the output signal of at least one of said first signal outputting means and said second signal outputting means when said light source does not generate said infrared radiation;storage means for storing data specific to said first and second photoconductive infrared detectors, said data relating to the resistance and a sensitivity; andcorrecting means for correcting the AC component detected by said AC component detecting means, based on the data stored in said storage means and the DC component from the output signal of at least one of said first signal outputting means and said second signal outputting means.