Condition monitoring of paper machine with thermal imaging

This technical paper describes the requirements to effectively use thermal imaging as a means of monitoring rotating machine components in a paper machine. The present efforts are focused mainly on monitoring polymer-covered rolls in paper machine calenders, but the studies will be expanded in the future to monitoring the temperature profiles of paper machine press fabrics and press belts in shoe presses. The main challenges in these areas are the high speeds of the target surfaces, obtaining adequate temperature difference resolution at relatively low surface temperatures and challenging environmental conditions. Adaptive triggering is discussed as a synchronization method for obtaining an adequate number of images from the target. Also some image processing techniques, test results and required qualities of infrared camera technology are presented.