Detecting surface stains using high absorbance spectral regions in the mid-ir

摘要

Methods and systems for detecting the presence of an inconsistency in or on a surface are generally provided. The method can include directing a modulated light beam (e.g., having a wavelength of about 3 mum to about 20 mum) from a light source to a mirror. The mirror then directs a reflected light beam onto the surface (e.g., directly onto the surface or indirectly onto the surface via a additional mirror(s)). The mirror is controlled to scan the reflected light beam across the surface. A specular reflection from the surface can then be detected in each light cycle, and the presence of the inconsistency on the surface can be detected.