PHOTODETECTOR FOR CALIBRATION

摘要

PROBLEM TO BE SOLVED: To provide a photodetector for calibration that stably makes the wavelength of laser light to conform to the absorption wavelength of a gas in order to improve the measurement accuracy of the gas. SOLUTION: In this photodetector for calibration, a gas cell 2 and a light receiver 3 are integrally provided. The laser light 4 emitted from a laser light source 1 is made incident to a container 5 containing the gas 8 through the light entrance window 6 of the container 5. The laser light is diffused into diffused light 13 by means of a light diffusing body 12 while the laser light is absorbed by the gas 8 and part of the diffused light 13 is emitted from the light emitting window 7 of the container 5 and received by means of a photodetecting element 11. The deviation of the wavelength of the laser light 4 from the absorption wavelength of the gas 8 is detected from the quantity of the light received by means of the element 11.