Optically sensing gaseous molecular species using diffractive element

摘要

A gaseous molecular species or mixture thereof is optically sensed by generating a light beam having a wavelength spectrum characteristic of the molecular gas species or mixture of gas species by illuminating a diffractive element 10 whereby light of wavelengths absorbed by the molecular species is diffracted. The gas species under interrogation is introduced into a sample test cell and the light beam is directed through the sample, and the attenuation of light is observed after having passed through the sample. A broad-band light source 42, screen 50, image plane 52 and aperture 54 are shown. IMAGE