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Accuracy of NIRS Instruments to Analyze Forage and Grain 1
Author(s) -
Shenk John S.,
Westerhaus Mark O.
Publication year - 1985
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1985.0011183x002500060054x
Subject(s) - monochromator , forage , silage , spectrometer , hay , filter (signal processing) , dry matter , instrumentation (computer programming) , neutral detergent fiber , analytical chemistry (journal) , materials science , remote sensing , optics , mineralogy , wavelength , agronomy , chemistry , biology , physics , computer science , chromatography , geology , computer vision , operating system
A study was made of the relative accuracy of three near infrared reflectance (NIR) instruments: a monochromator and two lower cost scanning filter instruments. All instruments used in this test were manufactured by Pacific Scientific, Silver Spring, MD. The monochromator was the 6100 with a scanning range of 1100 to 2498 nm. The 51A had a scanning range from 1596 to 1756 nm and 1988 to 2356 nm. The 102 scanned from 1902 to 2320 nm. Computer programs developed for the National NIR Forage Project were used to conduct the instrument comparisons tests. Agricultural products used in the experiment were hay, haylage, corn ( Zea mays L.) silage and corn grain. Analyses included crude protein (CP), acid detergent fiber (ADF), Ca, P, K, M, and dry matter (DM). The 6100 generally had lower standard errors of validation than the scanning filter instruments. Although the six‐filter 51A had more spectral information than the three‐filter 102, it did not consistently out‐perform the 102. There was no trend for one math treatment or series of wavelengths to be selected across instruments, products, or analyses. Regardless of the instrument spectral capabilities, the fraction of explained variance (R 2 ) values for CP, ADF, and DM were higher than the R 2 s for the minerals. Even though the accuracy of the filter instruments was often below that of the scanning monochromator, the differences were small and would be of little significance for many agricultural applications.