Multi sensor clearance probe

摘要

A multi sensor clearance probe (1) with at least longitudinally and transversely spaced apart first and second sensors (2, 3) operable to measure first and second distances (D1, D2) respectively between the sensors and a longitudinally spaced apart rotating rotor (30). The sensors being operable to measure blade tip clearances between radially outer turbine blade tips (82) and an annular stator shroud (72) circumscribing the blade tips (82). The blade tips (82) may be squealer tips and the sensors operable to measure the distances between the sensors and tops (137) of squealer tip walls (129) and outwardly facing walls (131) within cavities of the squealer tips. The probe may be operably connected to a controller (48) for sending signals to the controller (48) indicating the first and second distances (D1, D2) for controlling an air valve (44) used for active clearance control. Two or more of the probe may be used to determine rotor centerline offset (120).