1.1 ,This test method covers a procedure for determination of the rate of transmission of oxygen gas, at steady-state, at a given temperature and %RH level, through film, sheeting, laminates, co-extrusions, or plastic-coated papers or fabrics. This test method extends the common practice dealing with zero humidity or, at best, an assumed humidity. Humidity plays an important role in the oxygen gas transmission rate (O₂GTR) of many materials. This test method provides for the determination of oxygen gas transmission rate (O₂GTR), the permeance of the film to oxygen gas (PO₂), the permeation coefficient of the film to its thickness (P”,O₂), and oxygen permeability coefficient (Pʹ,O₂) in the case of homogeneous materials at given temperature and %RH level(s).