NIR remission spectroscopy of turbid media

摘要

We present a method for the determination of absorption spectra in VIS and NIR spectra of turbid media without the need for calibration. Measurements of the absorption spectra of a phantom and butter are presented. In process control the knowledge of the quantitative distribution of the ingredients is important. This can be achieved by measuring the remission spectrum and by comparing with calibration spectra. However, this method cannot separate the reduced scattering coefficient μ′_s from the absorption coefficient μ_a, e.g. an unnoticed change of μ′_s is interpreted as a change in μ_a. In contrast, a combination of the spatially resolved reflectance and the total reflectance enables the determination of μ_a undisturbed by scattering. At the same time it delivers a high wavelength resolution.