System for computer assisted monitoring of a cross profile of a quality parameter in a material web

A system for computer assisted monitoring of a cross profile of a quality parameter of a material web, especially a paper or cardboard web during its production and/or conversion, which includes a measuring system for measuring the cross profile, at least one computer based operations and logic unit for the determination of the standard deviations of at least two interference profiles that are representative for different interferences in the form of different peak groups in the measured cross profile. The different peak groups differentiate in that their peaks have different width ranges. Elements for storage, display and/or further processing of the determined standard deviations are also included.