Patent ID: 7373823

Claim:
A method for determining stress of at least one turbine blade or vane of a plurality of turbine blades or vanes that are arranged in rows of a turbine machine, comprising: providing at least one electromagnetic wave emitter for emitting at least one electromagnetic emission wave; providing at least one electromagnetic wave receiver for receiving at least one electromagnetic receive wave; converting the electromagnetic emission wave into the electromagnetic receive wave by at least partially reflecting the electromagnetic emission wave by providing the at least one turbine blade or vane with a reflection surface arranged on a contoured airfoil surface of the blade or vane; arranging the electromagnetic wave emitter and the electromagnetic wave receiver at least one location between the blade or vane rows and operatively connected to the reflection surface of the blade or vane; matching the electromagnetic emission wave to a surface form of the blade or vane; emitting the electromagnetic emission wave by the electromagnetic wave emitter; converting the electromagnetic emission wave into the electromagnetic receive wave by the reflection surface of the blade or vane; receiving the electromagnetic receive wave by the electromagnetic wave receiver; and determining the stress of the blade or vane by frequency analysis to assist in determining component integrity by analyzing the received electromagnetic receive wave to effect an evaluation of the reflection surface by the at least one analyzer.