High resolution probe for corrosion monitoring using hyper spectral imaging

Inspection of corrosion in obscure and difficult to access areas is of utmost importance in aeronautical industry. Continuous real-time monitoring of corrosion can reduce the risk of unexpected failures of the system. Current techniques used for monitoring corrosion in human inaccessible areas are based on borescopes, which captures color images (RGB) of the area under investigation to classify various corrosion stages. Existing borescopes don't offer high resolution inspection or automation possibilities. In this context, we propose a hyperspectral imaging (HSI) probe that offers high resolution imaging and automation possibilities for inspection of corrosion. The proposed HSI modality captures reflectance at several wavelengths from several spatial points of the sample and provides an immense amount of spectral information compared to RGB images. The acquired data is stored in the form of datacubes and a rigorous analysis of the data based on a reference spectral library provides information about the corrosion stage. This technique offers high-speed and non-contact inspection of corrosion and the flexible fiber probe can be used to inspect difficult to access areas similar to a borescope. A non-uniformly corroded sample is chosen for demonstration and the corrosion at different spatial points of the sample are analyzed. The recorded data after appropriate calibration and analysis can be used for the accurate classification of corrosion. A comparison of the corrosion monitoring capability of different optical techniques is also presented.