FIELD: determining atmospheric gas mixture component in containment of nuclear power plant by metering temperature variations caused by catalytic reaction. SUBSTANCE: gas mixture brought to catalyst is thinned with working gas of known composition. Jet pump used for thinning is connected to working-gas pipeline on inlet side and to catalyst on outlet side. Best proportion for thinning is 1:1 - 1:10. Inert gas (better nitrogen) is used as working gas. The latter contains oxidized component, better hydrogen or carbon oxide. Catalyst is heated. Filter is connected upstream of jet pump. The latter directly enters catalyst and is provided with gas-tight housing. Hydrogen concentration higher than 30 volume percent can be determined when oxygen component is below stoichiometric value. EFFECT: provision for determining any high component of mixture. 9 cl, 2 dwg
