Thermal Emissivity Imaging

Thermal Emissivity Imaging is a new thermographic method for the characterization of (semitransparent) thin films based on the analysis of thermal radiation (emissivity) by means of infrared or near‐infrared imaging (i.e. standard CCD cameras for temperatures above 400°C).
 
The field of metallic surface coating has found widespread industrial application in recent years (i.e. to improve wear and corrosion resistance etc.). Process control of such surface modifications is still a demanding task. It has been shown, that near‐infrared pyrometry / thermography is a promising approach with the potential for industrial application. Due to interference effects during thin film growth, characteristic emissivity signal variations can be observed which allow the determination of the optical constants (complex index of refraction) of the film without explicit knowledge of the optical properties of the substrate material. From this a very detailed analysis of growth characteristics (film thickness) becomes possible.