Turbine impeller blade thermal barrier coating layer thickness determining method, by comparing phase of received wave after reflection from impeller blade with phase of transmitted wave

摘要

At least one electromagnetic wave (31) is transmitted at a frequency matched to the layer thickness of the thermal barrier coating. The phase of the transmitted wave is compared with the phase of a received wave (32) that has undergone a phase change on reflection from an impeller blade (4), and the phase difference is used to determine the layer thickness. Independent claims are included for an apparatus for measuring thermal barrier coating layer thickness.