Method and apparatus for non-contact measurement of the concentration of molecules exceeding pre-dissociating states by means of laser-induced fluorescence

摘要

A description is given of a method and an apparatus for non-contact momentary measurement of the density distribution of a gas in a measurement volume, in which rotation transitions of a molecular component of the gas are excited by laser radiation, the excited state having a lifetime which is significantly shorter than the reciprocal collision frequency in the gas and the fluorescence intensity or absorption corresponding to the rotation transitions being measured. The density can be calculated from the measured intensity.