Microwave detector as used to monitor health/maintenance status of aircraft engine's turbine blades in hot gas

The paper has been intended to present some selected issues of taking measurements of rotating components under extreme operating conditions, in particular at high temperature. Tests have been suggested with microwave detector of motion applied, one that co-operates with systems using both the homodyne detection of a high-frequency signal and the frequency-based measurement of time intervals. Fundamental technical problems of the method while taking measurements on a real object have also been indicated.