Professor : Byoung-Kwan Cho Development of Laboratory based
portable spectrometer Lalit Kandpal |Kwon kyung-do |Min Hyun jung
|Dewi Kusumaningrum |Collins
1ContentsSpectrometer developemnt1Sample spectra collection2Data
analysis 43Wavelength calibrationResults5System components
Accessories for spectrometer development
System hardware
General principle of spectrometer
crossed czerny-turner spectrograph arrangement
Laboratory developed spectrometer
Orange juice Sample Preparation10 samples each
concentrationTotal :100 samples
3%5%7%10%13%15%17%20%25%22%
For the development of PLS model large amount of samples
require, therefore in this study we used 100 samples. Where,
Calibration 70 & validation 30 samples.
SPLICCO
CSharpData acquisition softwareHardware calibrationData
acquisition
DarkReferenceSample123Spectra collection procedureWavelength
calibration with LED light
Waveband (Hyper)Pixel
(spectrometer)459.4448531.1626550.1660736.41064893.91449
HSI spectra of LED light LED spectra from spectrometer
Correlation between waveband (hyper) & pixel (spectrometer)
Mean spectra
Raw spectra
600 nm: due to the yellow color of juice samples Absorbance
decreases as the concentration increases Raw spectra of orange
juice
Spectral data (X) Juice concentration (Y)PLS finds a set of
orthogonal components that :maximize the level of explanation of
both X and Yprovide a predictive equation for Y in terms of the
XsThis is done by:fitting a set of components to X (as in
PCA)similarly fitting a set of components to Yreconciling the two
sets of components so as to maximize explanation of X and Y
X = TP + EY = UQ + FWhere, T= scores/latent vector of X,
P=loadings for XU= Scores of Y, Q=loadings of Y, E & F =error
of X &Y Data matrix for PLS analysis Data processing
(PLS)CalibrationPredication Results: Predicted concentration
Optimal PC no. computed by cross-validation (leave one
out)ResultsBeta coefficient of PLS model
colorcolorConclusion & further modificationProper focusing
and handling was difficult task during spectrometer development
therefore in further modification accurate calibration of spectra
and light is highly essential.In future work LABVIEW program will
be developed for calibration and data acquisition.Thank You
!Chungnam National University, Daejeon, S. KoreaNon-destructive Bio
Sensing Laboratory
