Process NIR
Spectrometer System
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Fast-Precise-Robust
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Perfect for demanding process applications
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Modern detector array technology, no moving parts
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Various spectral ranges available from 190 nm to 2150 nm
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Permanently calibrated
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USB/Ind Ethernet interfaces connection to computers
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Standard SMA fiber-optic connection
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Easy connection to fiber-optic immersion probes and flow cells

What is NIR spectroscopy
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Near InfraRed Spectroscopy (NIRS) Absorption bands in the near infrared region: 750-2500 nm
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Usually weak and broad bands because of vibrational overtones and combination bands when two molecular vibrations are excited simultaneously.
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The intensity of overtone bands reduces by one order of overtone for each successive overtone.
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Usually high signal to noise ratio due to intense radiation sources and NIR is able to penetrate undiluted samples and use longer path lengths
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Fast measurement, very useful for rapid measurement of more representative samples
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NIRS is a secondary analytical technique. Chemometric model building needed for both qualitative and quantitative analysis
Advantages of NIR Spectroscopy
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Fast measurement
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No sample preparation needed
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Non-destructive, non-invasive
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Suitable for in-line applications
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Measurement can be done through transparent
containers and glasses -
Sensitive to any molecule containing
C-H, N-H, S-H or O-H -
Qualitative and Quantitative analysis
Absorption & Transmission
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Quantitative analysis: concentration determination for transparent liquid solution
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Beerβs law
The transmission of light through a solution of fixed pathlength is proportional to the concentration. -
Transmission:
π=πΌ/πΌ_0 =10^(βπ(π)ππ) -
Absorption:
π΄=logβ‘γπΌ_0/πΌγ=π(π)ππ
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π: molar absorptivity as a function of wavelength
c: concentration of the compound in solution
d: path length of the sample, a fixed quantity defined by a cuvette diameter or sample probe gap
Diffuse Reflectance
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Signal generated from both absorbance and scattering.
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Concentration determination for solid samples, powders, and non-transparent medium
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Obtaining bulk properties such as density, viscosity, fuel octane number, fruit ripeness, etc.
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Determination of physical properties such as particle size, mechanical properties, molar masses of polymers, etc.
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Multivariate analysis β chemometric model is usually used due to complex nature of NIR spectral region
Chemometrics β use of mathematical and statistical techniques for extracting relevant information from analytical information contained in the NIR spectral data
Transmittance Through Scattering
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Signal generated from transmission through scattering medium
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Concentration determination for solid samples, powders, and non-transparent media
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Determination of pharmaceutical API dosage in tablet β Content Uniformity (CU)
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Providing volumetric info on solid sample that is more accurate than those generated from surface dominated diffuse reflectance measurement
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Multivariate analysis β chemometric model is usually used due to complex nature of NIR spectral region
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Chemometrics β use of mathematical and statistical techniques for extracting relevant information from analytical information contained in the NIR spectral data