Preliminary Assessment of Portable Color Spectrophotometer Measurements of Cotton Color

Cotton in the U.S. is classified for color using the Uster® High Volume Instrument (HVI), using the parameters Rd (diffuse reflectance) and +b (yellowness).  It has been reported that some cotton bales, especially those transported overseas, appear to have changed significantly in color from their initial HVI color measurements, especially for yellowness.  Interest has been expressed in “on-site”/remote location measurements of cotton color that will yield “real time” color values, with emphasis on yellowness.  A program was implemented to determine the feasibility of using portable color spectrophotometers to measure cotton color in remote locations (e.g., warehouse, mill, overseas).  Using AMS standard tiles, cotton biscuits, and routine cottons, comparative evaluations were performed to establish the relationships between the HVI Rd - +b and portable spectrophotometer L*a*b* color parameters.  Preliminary results were very encouraging.  Excellent linear agreement (high R²s), low spectrophotometer standard deviations, and a low number of outliers were observed.