FIELD: study of physical and chemical properties of materials, determination of gas permeability of films. SUBSTANCE: process lies in positioning of tested specimen between two chambers, in evacuation of air from chambers, in formation and keeping of constant partial pressure of gas which permeability is to be found in first chamber in the course of full observation time, in placement of substance which reacts with gas in second chamber coming from first chamber with formation of second gas which permeability is also determined, in subsequent recording of pressure in second chamber till stationary course of process characterized by constancy of rate of change of pressure in each chamber is obtained and in calculation of coefficients permeability of gases by following formulas: 
, 
, where W1,W2 are free spaces correspondingly of first and second chambers; Vst is rate of change of pressure under stationary course of process; α is coefficient numerically equal to number of moles of second gas formed during reaction with substance of one mole of first gas; ε is ratio of area of specimen to thickness; R is universal gas constant; T is temperature; P1 is partial pressure of gas in first chamber reacting with substance; P1,P2 are pressures in first and second chambers correspondingly. Specific feature of process consists in placement in second chamber of substance reacting with gas coming from first chamber with formation of second gas, in recording of change of pressure in first chamber till stationary course of process is reached and in subsequent calculation of permeability coefficients of each gas by above-given mathematical dependences. EFFECT: increased authenticity of process. 2 dwg
