Abstract:In order to meet the measurement requirements of gas turbine tip clearance,the two-circle reflective coaxial fiber probe was designed. First,an output function of the fiber sensor was gained based on light intensity coupling principle analysis. Second,the effect of angle of inclination on reflective optical fiber displacement sensor characteristics is analyzed. Then,the tip clearance measurement system was designed. Finally,the static and dynamic measurement experiments were completed. The results show:sensor designed linear measurement range is 2mm ,and the dynamic performance of measurement system designed meet the requirements well.