| 摘要 |
PROBLEM TO BE SOLVED: To provide a gap measurement apparatus capable of reducing the number of components and accessory equipment and measuring a gap continuously.SOLUTION: A gap measurement apparatus comprises: a fiber Bragg grating element 3 disposed between a fixed section 10 and a movable section 20 of equipment in such a manner that end portions are oriented to the fixed section 10 and the movable section 20, respectively; a light source 1 emitting light incident on the fiber Bragg grating element 3; a measuring instrument 4 measuring reflection light from the fiber Bragg grating element 3; and a control unit 5 acquiring a gap H between the fixed section 10 and the movable section 20 on the basis of a waveform of a reflection intensity of the reflection light from the fiber Bragg grating element 3, a length of the fiber Bragg grating element 3 changing to be small in response to a change of narrowing the gap H between the fixed section 10 and the movable section 20.SELECTED DRAWING: Figure 1 |
