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Copyright © 2019 tec5USA | 80 Skyline Drive , Plainview, NY | Phone: (516) 653-2000

Process NIR

Spectrometer System

  • Fast-Precise-Robust

  • Perfect for demanding process applications

  • Modern detector array technology, no moving parts

  • Various spectral ranges available from 190 nm to 2150 nm

  • Permanently calibrated

  • USB/Ind Ethernet interfaces connection to computers

  • Standard SMA fiber-optic connection

  • Easy connection to fiber-optic immersion probes and flow cells

What is NIR spectroscopy

  • Near InfraRed Spectroscopy (NIRS) Absorption bands in the near infrared region: 750-2500 nm

  • Usually weak and broad bands because of vibrational overtones and combination bands when two molecular vibrations are excited simultaneously. 

  • The intensity of overtone bands reduces by one order of overtone for each successive overtone. 

  • Usually high signal to noise ratio due to intense radiation sources and NIR is able to penetrate undiluted samples and use longer path lengths

  • Fast measurement, very useful for rapid measurement of more representative samples

  • NIRS is a secondary analytical technique. Chemometric model building needed for both qualitative and quantitative analysis

Advantages of NIR Spectroscopy 

  • Fast measurement

  • No sample preparation needed

  • Non-destructive, non-invasive

  • Suitable for in-line applications

  • 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

  • Quantitative analysis: concentration determination for transparent liquid solution

  • Beer’s law
    The transmission of light through a solution of fixed pathlength is       proportional to the concentration.

  • Transmission:     
    𝑇=𝐼/𝐼_0 =10^(−πœ€(πœ†)𝑐𝑑)

  • Absorption:  

     π΄=log⁑〖𝐼_0/𝐼〗=πœ€(πœ†)𝑐𝑑

  • πœ€: 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

  • Signal generated from both absorbance and scattering.

  • Concentration determination for solid samples, powders, and non-transparent medium

  • Obtaining bulk properties such as density, viscosity, fuel octane number, fruit ripeness, etc.

  • Determination of physical properties such as particle size, mechanical properties, molar masses of polymers, etc.

  • Multivariate analysis – chemometric model is usually used due to complex nature of NIR spectral region
    Chemometrics – use of mathematical and statistical techniques for extracting relevant information from analytical information contained in the NIR spectral data

     

Transmittance Through Scattering

  • Signal generated from transmission through scattering medium

  • Concentration determination for solid samples, powders, and non-transparent media

  • Determination of pharmaceutical API dosage in tablet – Content Uniformity (CU) 

  • Providing volumetric info on solid sample that is more accurate than those generated from surface dominated diffuse reflectance measurement

  • Multivariate analysis – chemometric model is usually used due to complex nature of NIR spectral region

  • Chemometrics – use of mathematical and statistical techniques for extracting relevant information from analytical information contained in the NIR spectral data