near infrared (nir) spectroscopy instrumentation paul geladi
DESCRIPTION
Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi. Paul Geladi. Head of Research NIR CE Chairperson NIR Nord Unit of Biomass Technology and Chemistry Swedish University of Agricultural Sciences Umeå Technobothnia Vasa paul.geladi @ btk.slu.se paul.geladi @ uwasa.fi. Content. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/1.jpg)
Near Infrared (NIR) Spectroscopy Instrumentation
Paul Geladi
![Page 2: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/2.jpg)
Paul Geladi
Head of Research NIRCEChairperson NIR Nord
Unit of Biomass Technology and ChemistrySwedish University of Agricultural SciencesUmeåTechnobothniaVasa
paul.geladi @ btk.slu.se paul.geladi @ uwasa.fi
![Page 3: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/3.jpg)
![Page 4: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/4.jpg)
Content
• Spectroscopy?• Instrumentation• Modes of measurement
![Page 5: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/5.jpg)
Content
• Spectroscopy?• Instrumentation• Modes of measurement
![Page 6: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/6.jpg)
Content
• Spectroscopy?• Energy levels in atoms, molecules, crystals• Example IR-NIR calculations• Related techniques
![Page 7: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/7.jpg)
Content
• Spectroscopy?• Energy levels in atoms,molecules, crystals• Example IR-NIR calculations• Related techniques
![Page 8: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/8.jpg)
Spectroscopy
• Interaction of radiation and matter
• Electromagnetic radiation
• Gases, liquids, solids, mixtures
• Heterogeneous materials
![Page 9: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/9.jpg)
Electromagnetic radiation
Cosmic Gamma Xray UV VIS NIR IR Micro Radio
![Page 10: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/10.jpg)
Electromagnetic radiation• Cosmic > 2500 KeV• Gamma 10-2500 KeV• Xray 0.1-100 KeV• Ultraviolet 10-400 nm• Visible 400-780 nm• Near Infrared 780-2500 nm• Infrared 2500-15000 nm• Microwave GHz• Radio MHz-KHz
![Page 11: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/11.jpg)
Why interaction?
• Photon energy matches some energy level
• E = h• E = hc/• Planck’s constant 6.63 10-34
![Page 12: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/12.jpg)
Some useful constants
• qe= 1.602176462*10-19 As
• me = 9.10938188*10-31 Kg
• c = 2.99792458*108 m/s
• h = 6.62606876*10-34 Js
• 1 Joule to Electronvolt 6.241506363094028*1018
![Page 13: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/13.jpg)
Units
• Joule (energy)
• Electron volt (KeV)
• Wavelength (nm, m, mm)
• Inverse cm (cm-1)
• Frequency (GHz,MHz,KHz)
![Page 14: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/14.jpg)
Content
• Spectroscopy?• Energy levels in atoms,molecules, crystals• Example IR-NIR calculations• Related techniques
![Page 15: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/15.jpg)
HCl molecule (no true sizes)
HCl
UV,VISXray
UV,VIS
NIR,IR
Gamma ray
= electron
![Page 16: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/16.jpg)
Photon-matter interaction
• Atomic nucleus = gamma ray
• Inner electron = Xray
• Outer electron, chemical single bond = UV
• Chemical double, triple bond = UV,VIS
• Molecular vibration overtone = NIR
• Molecular vibration = IR
• Molecular rotation = Micro
![Page 17: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/17.jpg)
E
h
Ground level
First excited level
Quantized energy levels
![Page 18: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/18.jpg)
What can be measured?
• Emission
• Absorption
• Fluorescence
![Page 19: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/19.jpg)
E
h
Ground level
First excited level
Emission
Thermal
![Page 20: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/20.jpg)
E
h
Ground level
First excited level
Absorption
Thermal
![Page 21: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/21.jpg)
E
h
Ground level
First excited level
Fluorescence
h out
![Page 22: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/22.jpg)
Techniques?
• Gamma spectrometry• Instrumental neutron activation analysis• Xray spectrometry• UV-VIS spectrometry (AES,AAS,ICP...)• NIR spectrometry• IR spectrometry• Raman spectrometry• Microwave spectrometry
![Page 23: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/23.jpg)
What can be used?
Intensity
Energy
Position
Intensity, integral
Width
![Page 24: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/24.jpg)
Special topics
• Polarization
• Time resolved spectroscopy
![Page 25: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/25.jpg)
Content
• Spectroscopy?• Energy levels in atoms,molecules, crystals• Example IR-NIR calculations• Related techniques
![Page 26: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/26.jpg)
Vibrational spectroscopy
![Page 27: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/27.jpg)
Morse curves
The Morse curve describes the potential energy V of a diatomic molecule as a function of interatomic distance x.
V = De [1-exp(-bx)]2
![Page 28: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/28.jpg)
-2 -1 0 1 2 3 4 5 6 70
5
10
15
De = 5 b = 0.5
![Page 29: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/29.jpg)
• If the atoms go far apart the bond breaks.
• It is impossible to press the atoms close together. Enormous amounts of energy are needed.
![Page 30: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/30.jpg)
-2 -1 0 1 2 3 4 5 6 70
2
4
6
8
10
12
14
16
De = 10 b = 0.4
Zero = equilibrium distance
![Page 31: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/31.jpg)
-2 -1 0 1 2 3 4 5 6 70
2
4
6
8
10
12
14
16
Quantum levels = discrete
F
O1
O2
F FundamentalO1 First overtoneO2 Second overtone
![Page 32: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/32.jpg)
This was diatomic molecules
• Polyatomic molecules:
M=3N-6 quantized vibration modes
M=3N-5 linear molecules (N=1)
• N=3 , M=3 H2O, H2S, SO2
• N=4 , M=6 etc
![Page 33: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/33.jpg)
Triatomic molecules
• G(a,b,c)=v1(a+1/2) + v2(b+1/2) + v3(c+1/2)
• Energy levels
• a=b=c=0 (0,0,0)
• a=1 b=c=0 (1,0,0)
• a=2 b=c=0 (2,0,0)
• a=0 b=1 c=0 etc (0,1,0)
![Page 34: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/34.jpg)
a cb
Combination band
Overtone
Groundlevel
Hot band
Fundamental
(0,0,0)
(1,0,0)
(2,0,0)
(0,1,0)
(0,2,0)
(0,0,1)
(0,0,2)
![Page 35: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/35.jpg)
Intensity
• Some transitions are more probable
• Gives more intense bands
• Fundamentals in Gas phase
• Overtones in liquid,solid
• Combination bands in liquid, solid
![Page 36: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/36.jpg)
Hot bands
• Only exist because of thermal excitation
• Boltzmann
• Ne = No exp(-E/kT)
• Ne number excited, No number ground
• k Boltzmann constant 1.3806503*10-23 J/K
• E energy difference
![Page 37: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/37.jpg)
Why cm-1?
Additive
![Page 38: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/38.jpg)
S02
wavenumber band
519 v2
606 v1-v2
1151 v1
1361 v3
1871 v2+v3
2296 2v1
2499 v1+v3
![Page 39: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/39.jpg)
Thermal radiation
• Planck’s law
• W() = c1-5[exp(c2-1 T-1)-1]
• T °K
• c1 = 1.91*10-12
• c2 = 1.438*104
• m
![Page 40: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/40.jpg)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50
1
2
3
4
5
6
7x 10-14
m
Radiance
4000 K (Tungsten melts)
3500 K
3000 K
2500 K2000 K
![Page 41: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/41.jpg)
Planck curves
• More total energy for high temperature
• More UV for high temperature
• More flat curve for low temperature
![Page 42: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/42.jpg)
Content
• Spectroscopy?• Energy levels in atoms,molecules, crystals• Example IR-NIR calculations• Related techniques
![Page 43: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/43.jpg)
Energy supply
• Photon
• Thermal
• Electron -
• Proton +
• Ion + -
![Page 44: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/44.jpg)
Optics
• Electron optics
• Ion optics
![Page 45: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/45.jpg)
Techniques
• Electron microscopy
• Electron spectroscopy
• Mass spectrometry
• Ion microscopy
![Page 46: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/46.jpg)
Transmission
Readoutelectronics
Detector
Sample cell
Mono-chromator
Radiation source
![Page 47: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/47.jpg)
Transmission
Readoutelectronics
Detector
Sample cell
Mono-chromator
Radiation source
I0 It
![Page 48: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/48.jpg)
Lambert-Beer-Bouguer law
TransmissionAbsorbance
T = It / I0
A = log10 ( I0 / It) = -log10 (It / I0)
![Page 49: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/49.jpg)
Lambert-Beer-Bouguer law
A = klC
l = path lengthk = constantC = concentration
![Page 50: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/50.jpg)
Reflection
Readoutelectronics
Detector(s)
Sample cell
Mono-chromator
Radiation source
![Page 51: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/51.jpg)
Reflection
Readoutelectronics
Detector(s)
Sample cell
Mono-chromator
Radiation source
I0 Ir
![Page 52: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/52.jpg)
Lambert-Beer-Bouguer law
ReflectionPseudoabsorbance
R = Ir / I0
A* = -log10 (Ir / I0)
![Page 53: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/53.jpg)
Content
• Spectroscopy?• Instrumentation• Modes of measurement
![Page 54: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/54.jpg)
What can be changed?
• Radiation source
• Monochromator
• Sample cell
• Detector
![Page 55: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/55.jpg)
Radiation source
• Tungsten-halogen lamp (Car type)
• Coated tungsten SiC
• Laser(s)
• LEDs
• LED arrays
![Page 56: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/56.jpg)
ln(Wavelength), m
ln(Energy flux)
3000K
1000K
0.2 1
![Page 57: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/57.jpg)
Wavelength, m
Energy flux
1000
1150
1300
1520
LEDs
![Page 58: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/58.jpg)
What can be changed?
• Radiation source
• Monochromator
• Sample cell
• Detector
![Page 59: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/59.jpg)
Monochromator
• ”Glass filter”
• Interference filters
• Prism
• Grating
• Interferometer
• Electrooptical
![Page 60: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/60.jpg)
Monochromator
• ”Glass filter” not selective
• Interference filters
• Prism too primitive, never used
• Grating
• Interferometer
• Electrooptical
![Page 61: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/61.jpg)
Interference filter
Glass
High RI coating
Low RI coating
Multiple reflections
![Page 62: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/62.jpg)
Tilting interference filter
Glass
High RI coating
Low RI coating
Differentpathlengths
![Page 63: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/63.jpg)
There are also gradual interference filters
• Disk with increasing thickness
• Rotate for new wavelength bands
![Page 64: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/64.jpg)
Filter wheel
Readoutelectronics
Detector(s)
Sample cell
Radiation source
Filter wheel
![Page 65: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/65.jpg)
Grating
Mirror staircase
Pathlength difference
![Page 66: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/66.jpg)
Grating
Polychromatic
Monochromatic
Rotate
Entrance slit
Exit slit
![Page 67: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/67.jpg)
Interferometer
Fixed mirror
Moving mirror
Semitransparantmirror (50%)
Detector
Sample
![Page 68: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/68.jpg)
Interferometer
Fixed mirror
Moving mirror
Semitransparantmirror (50%)
Detector(interferogram)
a
b
Wavelengths for whichb-a = whole cycle reachdetector
![Page 69: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/69.jpg)
Interferometer
Interferogram
Fourier transform
Spectrum
![Page 70: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/70.jpg)
What can be changed?
• Radiation source
• Monochromator
• Sample cell
• Detector
![Page 71: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/71.jpg)
![Page 72: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/72.jpg)
Content
• Spectroscopy?• Instrumentation• Modes of measurement
![Page 73: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/73.jpg)
Modes of measurementThis is a real strong point of NIR spectroscopy. There are many modes of measurement:
• Transmission
• Diffuse reflection
• Fiber optic based
-Transflection
-Interaction
![Page 74: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/74.jpg)
DetIntegratingsphere
Det Det
Fiberoptic Fiberoptic Mirror
![Page 75: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/75.jpg)
Transflectance probe
Fiber bundle Sapphire mirror
![Page 76: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/76.jpg)
Mixed solutions
• Use tunable laser instead of monochromator (more lasers?)
• Use LED’s in different wavelengths instead of monochromator
• Use array of detectors instead of scanning monochromator
DIODE ARRAY
![Page 77: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/77.jpg)
Grating
Polychromatic
Entrance slit
Diode array
![Page 78: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/78.jpg)
Filter wheel instrument with interference filters
![Page 79: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/79.jpg)
Interferometricinstrument
![Page 80: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/80.jpg)
![Page 81: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/81.jpg)
Process NIR spectrometer based on moving grating
![Page 82: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/82.jpg)
Transmision instrument
![Page 83: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/83.jpg)
Sample changer for seeds (transmission)
![Page 84: Near Infrared (NIR) Spectroscopy Instrumentation Paul Geladi](https://reader031.vdocument.in/reader031/viewer/2022013012/56815b07550346895dc8b5da/html5/thumbnails/84.jpg)
Diffuse reflectance instrument (rotating cup)