Infrared thermography (IRT) and ultraviolet fluorescence (UVF) for the nondestructive evaluation of ballast tanks’ coated surfaces

This paper quantifies the detectability limits of infrared thermography (IRT) and ultraviolet fluorescence (UVF) techniques in the thickness measurements of the naval protective coatings applied on ship ballast tanks. The change in signal per unit thickness (25 μm) is used to describe each technique resolution, when using a pulsed-thermographic procedure and a UVF spectroscopic analysis. Furthermore, Tanimoto criterion in addition to a local signal-to-noise ratio (SNR) computation measure the revealability of pinholes, the IRT technique provides an 83% revealability while the UVF imaging has a 66% value. The goal of this work is to benchmark the novel UVF approach against that of the IRT procedures.