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United States Department of Agriculture

Agricultural Research Service

Title: Hvi Colorimeter and Color Spectrophotometer Relationships and Their Impacts on Developing "traceable" Cotton Color Standards

Authors
item Rodgers, James
item Cui, Xiaoliang
item Knowlton, James - USDA, AGRI. MARKETING SER
item Thibodeaux, Devron

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 3, 2008
Publication Date: October 21, 2008
Citation: Rodgers III, J.E., Cui, X., Knowlton, J., Thibodeaux, D.P. 2008. HVI Colorimeter and Color Spectrophotometer Relationships and Their Impacts on Developing "Traceable" Cotton Color Standards. Proceedings of the Internationl Conference on Sustainable Texiles. 254-257 CD-ROM.

Interpretive Summary: Color measurements of cotton fiber and cotton textile products are important quality parameters. The Uster® High Volume Instrument (HVI) is an instrument used globally to classify cotton quality, including cotton color. Cotton color by HVI is based on two cotton-specific color parameters—Rd (reflectance) and +b (yellowness). The HVI color standards are ceramic tiles and cotton biscuits provided by the Agricultural Marketing Service (AMS) of the United States Department of Agriculture (USDA). However, Rd and +b are not as well known as other globally recognized color systems (such as L*a*b*), and there are no traceable standards or traceability for the HVI standards. A program was implemented to examine the relationships of L*a*b* to Rd and +b, to investigate the possibility for “traceable” HVI color standards, and to study the impact of various instrumental and sampling parameters and conditions on the color results. Comparative evaluations were performed on several bench-top and portable color spectrophotometers with AMS standard tiles and cotton biscuits. Strong L* to Rd and b* to +b correlations were observed and validated on all units, which demonstrated a “universal” nature for relating L*a*b* from a color spectrophotometer to the HVI’s Rd and +b. These results are a key component in the quest for “traceable” cotton color standards. The impacts of glass use (normally required in the measurement of cotton color), instrument specular component, and pressure effects were investigated. The use of glass in front of the spectrophotometer port during color measurements yielded the main impacts on color results and between method agreements. Means for reducing the impact of glass use on the spectrophotometer color results were studied. These results indicate that the development and use of “traceable” color standards for HVI cotton color measurements is feasible.

Technical Abstract: Color measurements of cotton fiber and cotton textile products are important quality parameters. The Uster® High Volume Instrument (HVI) is an instrument used globally to classify cotton quality, including cotton color. Cotton color by HVI is based on two cotton-specific color parameters—Rd (diffuse reflectance) and +b (yellowness). The HVI color standards are ceramic tiles and cotton biscuits provided by the Agricultural Marketing Service (AMS) of the United States Department of Agriculture (USDA). However, Rd and +b are not as well known as other globally recognized color systems (e.g., CIELab), and there are no traceable standards or traceability for the HVI standards. A program was implemented to examine the relationships of CIELab to Rd and +b, to investigate the possibility for “traceable” HVI color standards, and to study the impact of various instrumental and sampling parameters and conditions on the color results. Comparative evaluations were performed on several bench-top and portable color spectrophotometers with AMS standard tiles and cotton biscuits. Strong L*'Rd and b*'+b correlations were observed and validated on all units, which demonstrated a “universal” nature for relating globally recognized color parameters (CIELab) from a color spectrophotometer to the HVI’s Rd and +b. These results are a key component in the quest for “traceable” cotton color standards. The impacts of glass use (normally required in the measurement of cotton color), instrument specular component, and pressure effects were investigated. The use of glass in front of the spectrophotometer port during color measurements yielded the main impacts on color results and between method agreements. Means for minimizing the impact of glass use on the spectrophotometer color results were studied. These results indicate that the development and use of “traceable” color standards for HVI cotton color measurements is feasible.

Last Modified: 11/1/2014
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