Determining method of the demands on rotating blades in a current machine, blades being fixed or arranged on a rotor shaft

摘要

At least one electromagnetic wave is emitted into a flow channel (6) in the region of the blades. The electromagnetic wave is at least partially reflected by at least one rotating blade. The reflected component is received and the stress on the blade can be determined from a signal corresponding to the wave. A measure of the stress could be the state of the surface of the blade. Independent claims also cover an apparatus for carrying out the method.