A fibre optic corrosion fuse sensor using stressed metal-coated optical fibres

A novel optical fibre-based corrosion sensor based on the mechanical failure of stressed metal-coated optical fibres when exposed to a corrosive environment is presented. The current work discusses proof-of-principle tests carried out using commercially available aluminium-coated optical fibres. Tests have been undertaken in a non-corrosive environment, in aqua regia and in sea water. The failure times of stressed aluminium-coated fibres were found to correlate with the corrosivity of the test environment. The results are discussed in relation to microscopic investigations of the metal coatings in the aforementioned corrosive environments as a function of immersion time.