Assessment of Color‐Measuring Instruments

Abstract

Abstract The U.S. Army has undertaken a program to develop an instrumental method for assessing the acceptability of textiles for color difference from a standard. This article reports the results of the first phase of the program, an assessment of three commercial color‐measuring instruments (Diano Match‐Scan, Hunter D‐54P‐5, Macbeth MS‐2000) for objective textile acceptability judgment. It is concluded that the three instruments are essentially equivalent in the precision and accuracy of the measurement of color and color difference using a wide variety of samples, at least over periods of up to seven weeks. All measures of repeatability lead to the conclusion that the uncertainties involved are well below the just‐perceptible color difference. Levels of absolute accuracy achieved depend greatly on the details of operation, data treatment, and calibration, but are considered satisfactory for each of the instruments tested. With respect to certain other parameters, the performance of the instruments is less satisfactory. Rejection of the specular component differs significantly among the three, as does the selection of weights for tristimuus calculations. One instrument, as tested, exhibited significant sensitivity to weave orientation in textile samples. Finally, we find that the distributions of tristimulus values obtained with each of the instruments show large deviations from normality, severely limiting the significance of conventional statistical treatment of such data.