Optical fibre distributed LHD with SMA element for discrete alarm

摘要

A temperature sensing system 10 comprises an optical waveguide 102, a shape memory alloy (SMA) element 106a, and an interrogator 12. The SMA element 106a is deformable as a function of temperature and at least partially surrounds the optical waveguide 102. The interrogator 12 is configured to detect distributed temperature along the optical waveguide 102 using spectroscopy and to detect strain in the optical waveguide 102 induced by deformation of the SMA element 106a to identify local hot spots along the optical waveguide 102.