Optical fiber distributed sensors hold great promise for corrosion monitoring in large structures. Systems based on
absorption losses are relatively well developed, whereas fluorescence systems have been comparatively neglected due to
the low efficiency of coupling light emitted in the cladding back into the core. This paper presents a model distributed
corrosion sensor based on fluorescence detection by photon counting. The model predicts sufficient sensitivity for
practical application under ideal conditions. Preliminary experimental results suggest that additional factors such as
scattering at the core-cladding interface and mode distribution effects can have a significant deleterious effect on the
performance in practice.