Apparatus for local sensing of nitric oxide as a pollutant

摘要

An apparatus is described which is capable of detecting 1/4 ppm of NO in a NOndash;N2mixture. The apparatus consists of a CO laser, which emits radiation that is absorbed by the NO in the mixture, the amount of absorption being proportional to the concentration of NO present. Optimum detection sensitivity is achieved when the mixture is situated in a magnetic field. The field shifts the absorption wavelength of the NO into coincidence with the fixed laser wavelength.