CLEARANCE MEASURING DEVICE, CLEARANCE MEASURING SENSOR AND CLEARANCE MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a clearance measuring device capable of accurately and stably performing clearance measurement in a rotary machine, and a clearance measuring sensor and a clearance measuring method.SOLUTION: The clearance measuring device is a device for measuring a clearance between the inner peripheral surface of a casing and outer periphery surface of a rotation body. The clearance measuring device is configured so as to: output rays of light having a first wavelength and a second wavelength toward the outer periphery surface of the rotation body; receive a reflectance from the outer periphery surface via a first filter which has a transmission bandwidth corresponding to the first wavelength; receive the reflectance via a second filter which has a transmission bandwidth corresponding to the second wavelength; and measure the clearance on the basis of a time difference of detection timing of the rotation body.SELECTED DRAWING: Figure 4