Clemens Klein

Photometrische Untersuchungen im sichtbaren und NIR-Bereich zum hochempfindlichen Nachweis der Verschmutzung und Abwitterung von Fassaden

Hochschule Neubrandenburg, 2008

Abstract: This work analyzes, the validity of the spectrometry in the visible and near infrared range to the comparative evidence of scaling, ageing or pollution changes occurring in the coating of thermal composite systems. As for that a series of definitely weathered samples has been analyzed. These samples were produced at the University of Wismar and at the University of Neubrandenburg. Analytical studies with these samples were carried out by using a combined VIS-NIR spectrometer, which measures the reflection spectra of the surfaces in the visible and near-infrared range. Visual assessments, light microscopy and scanning electron microscopy were used as reference procedures for the surface characterization.To photograph reflection spectra, a was developed that simplifies the analysis. Therewith reflection spectra can be measured and stored in data files and re-read. The created data files are in a format, which can be read by other applications, required for the analysis. In a preliminary investigation the spectral analysis was based on visual assessments, the classification for places and color due to a principal components analysis. The main components analysis is a method from the multivariate statistics. With this method, it is possible to depict graphically the similarities of reflection spectra graphically to determine the wavelengths responsible for group formation.

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