| 摘要 |
PROBLEM TO BE SOLVED: To measure measurement target gas concentration with high accuracy even in a measurement environment in which water of high concentration and noise exist.SOLUTION: A laser type gas analyzer for receiving a laser beam in a mid-infrared region including an optical absorption spectrum of measurement target gas, and calculating gas concentration from an amount of change of a signal component affected by optical absorption by the measurement target gas, includes: a near-infrared laser emission part 8 for emitting a laser beam of a near-infrared region including an optical absorption spectrum of water being present in an inside 1 of a flue without including the optical absorption spectrum of the measurement target gas; an optical system such as a lens 9 for irradiating the inside 1 of the flue with a near-infrared laser beam; a lens 14 and a near-infrared photodetector 13 for receiving the near-infrared laser beam and outputting it as an electric signal; a water concentration calculation part for extracting a signal component affected by optical absorption by water being present in the inside 1 of the flue from the electric signal and calculating water concentration from the amount of change therein, and a gas concentration correction part for correcting a concentration measurement value of the measurement target gas calculated by using the mid-infrared laser beam on the basis of the water concentration. |
