Temperature-compensated fibre optic strain gauge

Abstract

A temperature-compensated fibet optic strain gauge (10) for measuring strain of a host structure (5), the strain gauge (10) comprising: a mount (20) having a void (19) separating a first section (17) from a second section (18); a first fiber Bragg grating (FBG) (30); a second fiber Bragg grating (FBG) (40); and removable bridging portions (24) adjacent to the void (19) to connect the first section (17) to the second section (18), the bridging portions (24) being removed after the mount (20) is operatively attached to the host structure (5); wherein a right-side failure proof feature is provided by detecting whether a reflection wavelength reverts to an original Bragg wavelength of the first FBG (40) to indicate whether the first FBG (40) has broken. (See article file for the details of the abstract.)