부산대학교 도서관

Optical spectroscopies allow the identification and in some cases quantification of coloring species in a material through their wavelength‐dependent absorption in the ultraviolet–visible–near‐infrared (UV‐Vis‐NIR) wavelength region. Dissolved ions in glasses and crystals can be identified using ligand field theory, and mixed colors can thus be resolved and assigned to different ions. For pigments and different binders, a couple of databases are available for their identification through reference spectra. Quantification is based on Beer–Lambert's law, which can only be applied to spectra obtained in the transmission mode and is therefore limited to transparent samples. For semitransparent and opaque materials, reflectance measurements allow the application of optical spectroscopy to ceramics, glazes, enamels, frescoes, paintings, textiles, and even manuscripts. Typical instrumentation, basic methods for the interpretation of optical spectra of characteristic absorbing species, and the concept of color space are considered in this entry.