Infrared emission detection of a gas

An apparatus for detecting and making quantitative measurements of at least one selected component in a sample, in which at least one selected component of the sample, or at least one selected substance produced from the at least one selected component in the sample and characteristic of the at least one selected component, is introduced into an exciting means, and when the at least one selected component is present in the sample, gas-phase infrared-active molecules emit infrared radiation at at least one characteristic wavelength in proportion to the quantity of the at least one selected component in the sample, comprising:

• means for exciting the gas-phase, infrared-active molecules to emit radiation over a given path, wherein when the at least one selected component is present in the sample, the gas-phase infrared-active molecules emit radiation at the at least one characteristic wavelength with an intensity proportional to the quantity of the at least one selected component in the sample and wherein the means for exciting the gas-phase, infrared-active molecules is by furnace excitation, excitation by electron impact in a gas discharge or excitation by collisions with a vibrationally excited diatomic molecule;
• infrared discriminating and detector means located on said given path for detecting infrared radiation at the at least one characteristic wavelength and for generating an output signal representative thereof, and thereby determining the quantity of the at least one selected component in the sample.