The purpose of this effort is to apply an in-situ corrosion remote sensing capability in aircraft structural environments. The technique will permit detection of corrosion on and within aircraft structures and component junctions that are susceptible to corrosion, but which are not accessible for visual inspection. The field application configuration includes surface and embedded optical fiber probes interfaced with a Fourier Transform Infrared (FTIR) interferometer for evanescent wave absorption spectroscopic measurements. The mature and fielded technique will allow periodic remote sensing for structural health monitoring and detection of corrosion.

The potential advantages of optical fiber sensors result from the fact that the sensing element, the optical fiber, is small size, light weight, and immune to electromagnetic field. Also it can be attached to surfaces or embedded in junctions in aircraft structures, in locations where humidity and corrosion can accumulate, but cannot be directly observed.