Hyperspectral imaging analysis of corrosion products on metals in the UV range

Abstract

This work reviews and presents a comparison of hyperspectral imaging results when analysing corrosion products in the ultraviolet (UV) range (250 nm -500 nm), visible near-infrared (VNIR) range (400 -1000 nm) and shortwave-infrared range (900 -2500 nm). In related and prior work in our group, corrosion products on steel have been detected using hyperspectral imaging in the VIS, NIR and SWIR regions of the spectrum. However, an extensive review of the academic literature has revealed that the hyperspectral response of corrosion in the UV has not been reported. To address this, we present our results of imaging corrosion products on metal substrates using our Headwall UV-VIS Hyperspectral imaging sensor. These results are contrasted with the same samples imaged using our Headwall VNIR E series and Headwall SWIR 640 Hyperspectral imaging sensors. Our initial results indicate that corrosion spectra in the UV are separable from those of steel, but that the VNIR is the most appropriate range for this type of determination.