device for the manufacture of certain concentrations gasfoermiger substances and for mixing different gasfoermiger substances in a predetermined relationship.

摘要

Under the suction of a pump (15) preceding an analyser, qases are drawn from a number of prodn. sources (eg 1,2) each supplying a valve (1) having n inlets and m outlets, m and n being whole numbers. A storage container (13) forms a mixt. of gases from the individual components received whilethe valve is held in a setting to provide that component for a pre-determined time, dependent on the width of an impulse modulated by a micro-processor (12), thus producing the reqd. mixt.