LIGHT TRANSMISSION DETECTING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an included component density measuring method based on the phenomena that light transmissivity varies with included component density at light molecule vibration wavelengthλ1 and has little variation at base wavelengthλ2 irrelevantly to the included component density. SOLUTION: The light emission levels of the respective lights are set, so that an arbitrary level difference is generated between the photodetection output level when a sample 1 is irradiated with light having the light molecule vibration wavelengthλ1 and the photodetection output level when with light having the base wavelengthλ2 , and a measurement output (i) is obtained which is increased in the variation corresponding to the included component density of the sample 1 included in the photodetection output when the sample 1 is irradiated with the light having the light molecule vibration wavelengthλ1 .