Method for in situ runout measurement of large rolls

Abstract. This work presents a method for in situ runout measurement of large cylindrical rotors, such as paper machine rolls. The method is based on an acceleration sensor attached to a sliding probe which is held against the rotating surface. Measured acceleration signal is averaged and double-integrated using a computer to get radial surface displacement, i.e., runout. Laboratory tests showed that, with this method, it is possible to measure runout with accuracy in the scale of a few micrometers. Measurements showed that, by using this method, it is possible to detect and measure phenomena like thermal bending or so-called polygon effect in running thermo rolls. These pheno-mena have not been reported to have been measured in situ before