Abstract: In a quadrupole mass spectrometer enclosed by a high vacuum container and including an ionization chamber, a molecular beam radiator passing through the container and having an output opening for supplying the gas to be analyzed, and a cryopump arranged for receiving the molecular beam exiting from the output opening and serving as a radiation trap, the output opening of the radiator and the cryopump are disposed at the periphery of the ionization chamber preferably diametrically opposite one another.

Abstract: For measuring the proportion or quantity of a component in a radiation-transparent mixture, a beam is passed through the mixture and subsequently split by a beam splitter into a measuring beam and a reference beam. The measuring beam is passed through a narrow-band interference filter which has a transmitting wavelength that corresponds to a discrete absorption wavelength of the component. This filter is oscillated in a range of oscillation which traverses the absorption maximum. The reference beam is passed through a narrow-band interference filter which has a transmitting wavelength that differs from the absorption wavelength of the component. Subsequently, the radiation intensities of the measuring beam and the reference beam are separately detected and their difference is formed. This difference is a function of the proportion or quantity of the component.