This standard prescribes the method for determination of water vapour transmisssion rate, water vapour permeance and water vapour per-meability of rigid cellular thermal insulation materials. Rigid cellular materials with thicknesses from 3 to 80 mm and which may, as integral part of the material, contain natural skins or adhered facings of some different material, may be tested by this method.
IS 11239 Pt.4-1985 history
1985IS 11239 Pt.4-1985 Test methods for rigid porous thermal insulation materials Part 4 Water vapor transmission rate