Abstract: A system for monitoring and controlling the width of a product such as a sheet, film or tube includes, in the preferred embodiment, a line scan camera having a one-dimensional array of charge-coupled devices ("CCD's") for monitoring the width of the product. The CCD's develop an analog charge value which is proportional to the intensity of any light falling thereon; the analog nature of the CCD's allows subelement interpolation based on the voltage charge of two adjacent elements. This permits product width to be measured more accurately than was heretofore possible with electromechanical or photoelectric type systems.

Abstract: A system for monitoring and controlling the output of extruder apparatus for producing a blown synthetic resin film. An infrared imaging system provides for measuring the temperature of the blown film simultaneously at multiple points on the film between the blowing head and the frost line of the film bubble. The multi-dimensional temperature profile measured by an infrared camera is processed in a computer controller in order to provide control inputs to various components of the extruder apparatus. The extruder apparatus is controlled so as to maintain a desired temperature profile substantially at that which is known to provide a high quality end product.