METHOD DETERMINING CONCENTRATION OF COMBUSTIBLE GASES IN OXYGEN-CARRYING ATMOSPHERE Russian patent published in 2000 - IPC

FIELD: analysis of gaseous atmosphere. SUBSTANCE: thermal catalytic element is placed into measurement chamber and pulse of electric current are fed to it. Value of resistance Rτ_0-1 of thermal catalytic element at time moment within interval from τ₀ to τ₁ is measured beforehand, τ₀ being time moment before start of feed of pulse of electric current, τ₁ being time moment before start of oxidation reaction of combustion gases on surface of thermal catalytic element. Value Rτ_1-2 is also measured at time moment in interval from τ₁ to τ₂ where τ₂ is time moment from start of formation of heated gas boundary layer around thermal catalytic element at which feed of pulse of electric current is stopped. Then constant coefficient K= is found. After this current value Rτ₁ at time moment τ₁ and current value R^°τ₂ at time moment τ₂ are measured and value of resistance of Rτ₂= K•Rτ₁ of thermal catalytic element at time moment τ₂ is determined in absence of combustible gases in oxygen-carrying atmosphere. Later ΔRτ₂= Rτ₂-R^°τ₂ is determined and value ΔRτ₂ is used to evaluate concentration of combustible gases in oxygen- carrying atmosphere. Number of values of coefficient K at different temperatures of oxygen-carrying atmosphere in range from -70 C to +70 C is found to compensate for effects of temperature. Obtained values of coefficient K are approximated in the form of straight line and correction coefficient β is determined. EFFECT: provision for determination of integral explosion hazard of multicomponent gaseous atmosphere, prolonged service life of thermal catalytic elements and reduced energy consumption. 1 cl, 4 dwg