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Diffuse reflectance spectroscopy, or diffuse reflection spectroscopy, is a subset of absorption spectroscopy. It is sometimes called remission spectroscopy. Remission is the reflection or back-scattering of light by a material, while transmission is the passage of light through a material.
Spectrophotometry is a branch of electromagnetic ... and sometimes a percentage of reflectance measurement. A spectrophotometer is commonly used for the measurement ...
Parameters of interest, besides the wavelength of measurement, are absorbance (A) or transmittance (%T) or reflectance (%R), and its change with time. [4] [5] A UV-Vis spectrophotometer is an analytical instrument that measures the amount of ultraviolet (UV) and visible light that is absorbed by a sample. It is a widely used technique in ...
Attenuated total reflection (ATR) is a sampling technique used in conjunction with infrared spectroscopy which enables samples to be examined directly in the solid or liquid state without further preparation. [1] Light undergoes multiple internal reflections in the crystal of high refractive index, shown in yellow.
Fourier transform infrared spectroscopy (FTIR) [1] is a technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas. An FTIR spectrometer simultaneously collects high-resolution spectral data over a wide spectral range.
The spectra are plotted in units of log inverse reflectance (log 1/R) versus wavenumber. Alternative plots of Kubelka-Munk units can be used, which relate reflectance to concentration using a scaling factor. A reflectance standard is needed in order to quantify the reflectance of the sample because it cannot be determined directly. [2] [3]
Diffuse reflectance spectroscopy can be used to determine the absorption spectra of powdered samples in cases where transmission spectroscopy is not feasible. This applies to UV-Vis-NIR spectroscopy or mid-infrared spectroscopy. [9] [10]
Spectral reflectance curves for aluminium (Al), silver (Ag), and gold (Au) metal mirrors at normal incidence. The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary.