Split-replicates correlation of water content in cotton

Abstract

The range of water content in US cottons equilibrated to moisture equilibrium at standard textile testing conditions and analyzed by standard Karl Fischer Titration is small, <0.8%. This presents a challenge in obtaining accurate test data to calibrate fast sensors. A dozen raw cottons, nine American and three international, were analyzed for water by standard Karl Fischer Titration. The number of replicates analyzed, blending, and two conditioning systems – either standard room or closed chamber in the standard room with salt solution to control humidity – were examined. Split-replicates correlation within samples, by splitting out either half the available number or three replicates at a time, was used as the measure of correlation. The split-correlation results depended on the number of replicates, mixing of the laboratory sample, and method of conditioning. These results suggest that good correlations are possible when mean water content is the dependent variable in regressions with fast sensor data. This improved understanding of the correlation behavior, which is important for optimal application of methods to measure water in samples equilibrated to moisture equilibrium.