US 12,169,174 B2
Gas analyzer apparatus and gas analysis method analizing measurement target gas using laser light
Yoshihiro Deguchi, Tokushima (JP); and Takahiro Kamimoto, Tokushima (JP)
Assigned to SMART LASER & PLASMA SYSTEMS CO., Tokushima (JP)
Appl. No. 17/995,649
Filed by SMART LASER & PLASMA SYSTEMS CO., Tokushima (JP)
PCT Filed Apr. 1, 2021, PCT No. PCT/JP2021/014196
§ 371(c)(1), (2) Date Oct. 6, 2022,
PCT Pub. No. WO2021/205988, PCT Pub. Date Oct. 14, 2021.
Claims priority of application No. 2020-070788 (JP), filed on Apr. 10, 2020.
Prior Publication US 2023/0160819 A1, May 25, 2023
Int. Cl. G01N 21/39 (2006.01); G01N 33/00 (2006.01)
CPC G01N 21/39 (2013.01) [G01N 33/0027 (2013.01); G01N 2201/06113 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A gas analyzer apparatus comprising:
a laser light source configured to irradiate measurement target gas with laser light;
a laser controller configured to control the laser light source to change a wavelength of the laser light in a predetermined wavelength band;
a photodetector unit configured to photoelectrically convert laser light having passed through the measurement target gas into an electric signal, and output the electric signal; and
an analyzer configured to analyze an absorption wavelength of the measurement target gas based on the electric signal,
wherein the laser controller comprises:
a signal generator configured to generate a voltage signal of a rectangular wave or a trapezoidal wave; and
a current power supply configured to convert the voltage signal into a drive current of a rectangular wave or a trapezoidal wave, and causes the drive current to flow through the laser light source, and
wherein the laser controller controls the laser light source such that an intensity of the laser light changes in a shape having a flat portion that is at least substantially constant in a predetermined time interval only by current control using the signal generator and the current power supply, and then, an output of the laser light changes, the temperature of the laser light source changes, and a spacing between diffraction gratings of the laser light source changes, thereby changing a wavelength of the laser light in the time interval so as to be substantially proportional to passed time according to rise of the temperature of the laser light source with a delay from a rise of the intensity of the laser light.