Patent US 3,974,248

A system for determining and/or controlling the profile of a property of an article, in which sensing means simultaneously obtains a multiplicity of electrical gauging signals, each signal being proportional to a property of the article in a particular region, the gauging signals are passed to electrical circuit means which detect any difference in magnitude between the signals from a given region and the average for all such signals and deriving a functional signal for any such difference.