Fibre Bragg gratings are used to reflect light back to the Interrogator. As the grating is stretched, the wavelength it reflects changes. This is what the Interrogator uses to determine the strain at each sensor location.
The fibre optic cable is encased in a glass fibre patch. This protects the fibre, and the similar material types makes it easy to install into a blade. They are normally laminated over in the blade to ensure they are fully bonded and protected.
Sensors are IPx5 rated, and are typically 180 x 140mm.
