Avoidance of time-consuming calibration measurements in UV/VIS/NIR spectroscopy by understanding the light propagation in the scattering medium

In model-based UV/VIS/NIR spectroscopy, standard spectroscopy methods (possibly with optimized geometry) are extended by an evaluation based on radiative transfer theory. This allows the optical effects (scattering and absorption) to be separated. In the simplest case, scattering is described with a spectrally resolved effective scattering coefficient and absorption with a spectrally resolved absorption coefficient.

The effective scattering coefficient depends on the microstructure of the medium and the absorption coefficient results, in many important applications, from the linear superposition of the absorption coefficients of the individual ingredients. If the absorption spectra of the individual ingredients are known, their contents can then be determined without calibration by linear superposition of the initial spectra.