Spectral reflectance of the Philippine Island Government standards for abaca fiber

Abstract

This paper reports the results of spectral reflection measurements of one set of the official standards for the grades of abacd used in cordage. The results provide a quantitative record of those characteristics of the fiber on which the color depends. They should be of permanent value since the grading is largely on the basis of color. They suggest the possibility of using quantitative reflectance measurements in the Philippine Islands to supplement, if not to replace, the present method of grading abac£ for color. Three specimens representing the base, tip, and middle of each of 10 standard samples were measured at seven wave lengths. The average values found for the spectral reflectance at wave length 500 mju, which are illustrative of the results, follow: Superior current 59.3, good current 54.9, midway 49.9, 25 percent over fair current 46.5, streaky two 45.4, streaky three 33.5, fair current 42.5, superior seconds 40.0, soft seconds 31.3, soft brown 21.5. The highest and lowest measurement for a given standard differ by from 2 to 13 units and there is decided overlapping in the measurements for some of the different grades.