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Figure 8 Model optimization statistics for PLS calibration of A moisture, B oil, C protein, and D starch. Solid lines indicated RMSEC, dashed line represents RMSECV, and dotted line represents RMSEP for the validation set. factors are added. However, new samples not included in the calibration set will have a different realization of random errors. Therefore, the calibration model will not fit these errors to the same degree as the errors in the calibration set. When extra factors that mostly...
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Sharpening is a useful tool with naturally broad-banded samples when the goal is to develop calibrations or to understand why calibrations work. We conclude with Figures 17-20 that illustrate how sharpening can accentuate small differences in the spectra of Figure 2.
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Optronic Laboratories, Inc. Grating Type designation Wavelength range nm Polytec PI, Inc. Process Sensors Corp. Reedy Reflex Analytical Corp. Rosemount Analytical Scientific Apparatus Exchange SENTECH Instruments, GmbH Shimadzu Scientific Instruments Spectral Instruments, Inc. Spectr Alliance Spectrotech, Inc. Speim Grating Tecator Teledyne Brown Eng. Analyt. Inst. ThIS Analytical Trebor Industries
REFERENCES Ytu
1. C. M. Paralusz, ACS National Meeting, Abstr 85, 1987, Denver, CO. 2. F. A. DeThomas, Rocky Mt. Conference, Abstr 206, 1988. 3. C. M. Paralusz, Appl Spectr, 43 1273 1989. 4. P. J. Brimmer, Pittsburgh Conference, Abstr 1373. 1990, New York. 5. S. Monfre, Rocky Mt. Conference, Abstr 211 1990. 6. M. D. John and N. K. Keon, Applied Spectroscopy, 43 1399 1989. 7. F. Dannen and I. Silverman, The Supernote, The New Yorker, Oct 23, 1995 pp 49-55. 8. R. Lipkin, New Greenbacks, Science News, 149 58...
I INTRODUCTION Oyz
Near-infrared NIR spectroscopy has an established pedigree. When Herschel studied NIR energy in 1800, it was the first region of the electromagnetic spectrum to be discovered after the visible region . Almost a hundred years later the Michelson interferometer is often given as the historical beginning of Fourier transform FT spectroscopy. Almost a hundred years ago William Coblentz measured infrared IR spectra of organics. Almost 50 years ago, Karl Norris used NIR to characterize agricultural...
Ii Lambert Cosine Law
The phenomenon of diffuse reflection is easily observed in everyday life. Consider for example the intensity of radiation reflected from a completely matte surface. The reflected or remitted radiation is everywhere of the same intensity no matter what the angle of observation or what the angle of incidence. It was the same observation that led Lambert 1 to be the first to attempt a mathematical description of diffuse reflection. He proposed that the remitted radiation flux ,., in an area cm2,...
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Wavelength Bond Vibration Structure 1540 O-H stretch 1st overtone Starch 1570 N-H stretch 1st overtone CONH 1620 C-H stretch 1st overtone CH2 1685 C-H stretch 1st overtone Aromatic 1695 C-H stretch 1st overtone .CH3 1705 C-H stretch 1st overtone .CH3 1725 C-H stretch 1st overtone .CH2 1740 S-H stretch 1st overtone -SH 1765 C-H stretch 1st overtone CH2 1780 C-H stretch 1st overtone Cellulose 1780 C-H stretch HOH deformation combination Cellulose 1820 O-H stretch C-0 stretch 2nd Cellulose 1860...
WAVELENGTH Wfn
Figure 12 Decrease of the C-H of the epoxy group at 2208 nm and the appearance of the O-H group in the 1900-nm region for an epoxycarboxylic acid cure system. Resin formation is usually broken down to three stages A, B, and C. The A-stage resin is usually a thermoplastic that is insoluble in organic solvents. This material is typically dumped from a kettle, cooled, and then ground to a fine powder. Additives including fillers and colorants are added to the A-stage resin. Upon heating and...
V Grinders And Grinding
In the early days of NIR analysis, sample preparation usually involved grinding a sample of grain into meal. Attention has been drawn to the influence of grinder type and grain type on the granularity of the resultant whole-meal ll . But even a simple process such as grinding a sample of grain poses several questions. What type of grinder should be used Is a certain type of grinder best suited to a particular commodity What does the action of grinding do to a sample in terms of its composition...
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the final sample. It will tell us whether the sample would meet specifications laid down prior to purchase. It will enable us to predict the likely functionality of the entire parcel of material represented by the sample in the process for which it is intended. It will tell us the value of the sample, and therefore the price. But will it tell us everything we need to know Not necessarily. The truly representative sample can be dangerously misleading. A typical example of the unreliability of...
Application of NIR Spectroscopy to Agricultural Products
The Pennsylvania State University, University Park, Pennsylvania Kimberly-Clark Corp., Neenah, Wisconsin The Pennsylvania State University, University Park, Pennsylvania I. NIR TECHNOLOGY IN AGRICULTURE 1968 TO PRESENT A. Brief History Agriculture produces the food and fiber needed for human existence. Since the beginning of recorded history agricultural products have been marketed and fed on the basis of their volume or weight i.e., bushels, tons, etc. . In the past 100 years it became...
Iv Model Selection And Validation
There are two important validations that may be performed during multivariate calibration. The first validation is to determine if any of the samples in the calibration set are outliers. Outliers may be samples with unique spectral features that do not occur in the bulk of the other samples, samples with extreme properties that are outside the range of the other samples, or calibration samples that have been mislabeled. The validation test is determination and assurance of the optimal...
REFERENCES Olk
1. J. H. Lambert, Photometria sive de mensura et grodibus luminis colorum et umbrae, Augustae Vindelicorum, 1760. 2. G. Kortiim, Reflectance Spectroscopy, Springer-Verlag, New York, 1969. 3. W. W. Wendlandt and H. G. Hecht, Reflectance Spectroscopy, P. J. Elving and I. M. Kolthoff, eds. , Interscience, New York, 1966. 4. G. I. Pokrowski, Z. Physik, 30 66 1924 . 5. G. I. Pokrowski, Z. Physik, 35 35 1926 . 6. G. I. Pokrowski, Z. Physik, 36 All 1926 . 7. H. Wright, Ann. Physik, 1 17 1900 . 8. G....
Iii Polymer Applications Of Nearinfrared Analysis
NIR can be used in the feed preparation step to monitor the purity of incoming materials and to test for water content of raw materials. In the addition reaction step, the disappearance of the double bonds can be monitored using NIR. Terminal double bonds have a combination band at about 2110 nm and a first overtone band at 1620 nm. In the recovery phase, the residual solvent can be determined by NIR. NIR is not well suited for analysis of the backbone structure of the final product. One can...