Improved reference system for high precision blade tip timing on axial compressors

Blade tip timing is an upcoming technology to research possibilities of working point identification and phenomena like stall and blade vibrations for axial compressors. This method determines blade bendings for each individual compressor blade. Due to their high timing resolution optical sensors are often used in this field. Real blade bendings are often of very small amplitudes in the range of micrometers. So it's important to have a reference system that is as accurate as possible. This paper describes a method which guarantees a high resolution and high precision reference system to improve the results of blade tip timing.