New Methods of Noncontact Sensing of Blade Vibrations and Deflections in Turbomachinery

This paper is focused on new methods of noncontact sensing vibrations and deflections of rotating machine parts, especially blades of steam turbines. Special attention is paid to the induction and magnetoresistive (MR) sensors developed in the Institute of Thermomechanics for noncontact measurements of characteristics of rotating blades inside steam turbines under operation. Different principles of noncontact sensors based on measuring deflections or velocity components are described and compared, including new types of MR sensors. Hitherto unpublished principles of sensors intended for shrouded blades are described and discussed.