Measurement of porous film

摘要

An in-situ method of measuring properties of a moving porous film such as thickness, porosity and density uses measurements of the transmissivity of the porous film at a plurality of IR wavelengths at which the film exhibits substantially no absorption. The method provides a measurement related to scattering and from this measurement parameters of the porous film may be directly or indirectly determined using a multivariate regression model.A further method comprises calculating a first parameter of a material sample by determining a typical spectrum of the material, obtaining a spectrum of the sample, determining scatter correction parameters for the sample using a scatter correction model and using the correction parameters to calculate the sample first parameter.