| Abstract: | Principles of the conversion of a measured electrical signal to the relative humidity units have been worked out according to a theory of the method and the measuring system for water vapour permeability through packaging films measurement. The method and the system were based on sorptive sensor reaction inertia analysis. The constants of the measuring vessel were determined by means of the dish method for fixed measurement conditions. Using the developed theory, water vapour permeability was determined for the chosen films. The results obtained were in close agreement with values determined by the dish method and additionally for PET-50 film also in close agreement with the literature data. The uncertainty of the results obtained by this method was estimated. The relative mean uncertainty (α = 0.05) was Bp ≃ 1.1% and the relative maximum uncertainty of a single result Bpmax = 3.1%. |
