Multiple sensor measurements of web products

This paper looks at the problem of understanding the measurements from two dimensional industrial processes such as paper manufacture or plastic film extrusion. It describes the difficulties of obtaining a sampled data measurement that is free from aliased components and goes on to describe different methods of measurement and how they can be matched to the spectrum of the web product. It outlines how an understanding of the spectral properties of scanned data can lead to the reconstruction of two dimensional data profile in a way which is superior to current practice. The paper concludes with a description of a special machine developed to test and compare different methods of establishing cross direction pro-files.