A METHOD FOR CONTROLLING QUALITY AND CONDITION ON THE BASIS OF THERMAL IMAGING

摘要

The invention relates to a method in the process ofmanufacturing and/or finishing a fibre web (11), in whichmethod said continuous and moving web (11), and/or amoving means (16, 17) related to the processing of theweb (11), is monitored by one or more thermal cameras(10) of the infrared range or a corresponding detec-tor/detectors for the purpose of controlling the quality orcondition. According to the invention, a substantiallycontinuous two-dimensional thermal image or continu-ous thermal chart (20) of an object (11, 16, 17) beingmonitored and in a propagating and/or rotating move-ment is formed by said detector/detectors in a time-resolved manner and in synchronization with the move-ment of the object (11, 16, 17) in the direction of themovement. To determine the properties of the object(11, 16, 17) and/or to detect defects in the object fromthe continuous thermal chart (20), local deviationsand/or discontinuities (21, 22) in the temperature, par-ticularly in the direction of movement, are detected, andthe cause of said deviations and/or discontinuities (21,22) is identified on the basis of the periodicity of saidphenomena in the direction of movement.