[A method for ascertaining of the closing volume with argon for early detection of obstruction of the small airways (author's transl)].

Closing volume can be ascertained with Argon by the aid of the Quadrupol-mass-spectrometer produced in Hungary. The method is simple, sensible and applicable in the routine laboratorium for pulmonary function testing. It will show the obstruction of the small airways and the disturbance of gas distribution in the lower pulmonary parts already at a point of time when the usual spirometric methods are still inconspicuous.