What is meant by Attenuated Total Reflectance?
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.
How does Attenuated Total Reflectance work?
How does it work? An ATR accessory operates by measuring the changes that occur in an internally reflected IR beam when the beam comes into contact with a sample. This internal reflectance creates an evanescent wave that extends beyond the surface of the crystal into the sample held in contact with the crystal.
What is ATR in chemistry?
Attenuated Total Reflectance (ATR) is a sampling method that introduces light onto a sample in order to acquire structural and compositional information. ATR is one of the most used sampling technologies for FTIR Spectroscopy.
What is IR reflectance?
Reflectance infrared spectroscopy has been primarily used as a characterization tool to study the molecular orientation, average conformation order, and chemical identity of thin films (<10 nm) on metallic surfaces.
How does an IR work?
Infrared (IR) spectroscopy uses infrared radiation to excite the molecules of a compound and generates an infrared spectrum of the energy absorbed by a molecule as a function of the frequency or wavelength of light. IR spectroscopy therefore allows us to identify the various functional groups present in a compound.
What is ATR and FTIR?
Attenuated total reflection (ATR) is a method that allows the direct measurement of samples for FTIR. ATR method involves pressing the sample against a high-refractive-index prism and measuring the infrared spectrum using infrared light that is totally internally reflected in the prism.
Why is the reflectance attenuated at a particular angle of incidence?
At a particular angle of incidence, almost all of the light waves are reflected back. This invisible wave is called evanescent wave. The intensity of the reflected light reduces at this point. This phenomenon is called attenuated total reflectance.
What is spectral reflectance?
3.2. The spectral reflectance is the reflectance measured at a given Ts and λ, within a small wavelength interval, Δλ, centered at λ [7]. Spectral reflectance is typically named monochromatic reflectance and may be specular, diffuse, or hemispherical.
What equipment is primarily used in IR?
The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) which produces an infrared spectrum. An IR spectrum can be visualized in a graph of infrared light absorbance (or transmittance) on the vertical axis vs.