Submitted to: Engineered Fiber Selection Conference
Publication Type: Proceedings
Publication Acceptance Date: 4/1/2003
Publication Date: 5/1/2003
Citation: Montalvo Jr, J.G., Von Hoven, T.M. 2003. Advances in maturity measurements. Engineered Fiber Selection Conference. P. 129-135 Interpretive Summary: Calibration and proper upgrading are imperative to correlating fiber properties as measured on different Fineness and Maturity Testers, (FMTs). Following a strict testing quality control protocol, a comparison of fiber property measurements of two upgraded and calibrated FMTs demonstrated that the two FMTs were generating statistically similar data. However, a faster instrument to measure these properties is desirable. Based on the ability of the FMT to measure these properties, it can be used to calibrate the fast, accurate, and easy to operate Near Infrared instrument (NIR). Correlations between the FMT and NIR fiber property values are excellent and indicate that the NIR may be the method of choice in the future testing of these cotton fiber properties, thus benefitting fiber testing laboratories.
Technical Abstract: Because a rapid, accurate, easy means to measure maturity is needed to provide the cotton industry with additional fiber information, ongoing research has been conducted on measuring the maturity of a worldwide range of cottons by Near Infrared high volume instrumentation (NIR HVI). A total of 62 cottons were used in the work reported here, including 12 Fineness and Maturity Tester (FMT) calibration cottons. These cottons have been exhaustively studied by a variety of reference methods, including British Standard Methods and Image Analysis. These cottons were used to calibrate two FMTs using the constant offset technique that was proven successful on an instrument calibrated and upgraded previously (Von Hoven et al., 2001). Following a strict quality control protocol, a comparison of micronaire, fineness and maturity measurements of the two upgraded and calibrated FMTs demonstrated that the two instruments were generating statistically similar data. The FMT was used as the reference method for the other cottons tested by NIR HVI: 35 Australian cottons, 7 image analysis experimentation cottons, and 8 ATMI research cottons. To test the stability of the NIR instrumentation, the four groups of samples were analyzed separately over a two month period and the spectra combined into a single calibration file. The NIR algorithm used was partial least squares (PLS) with one-out-rotation. Correlations between the FMT and NIR maturity measurements was very good, R = 0.9743. This work confirms the accuracy of the FMT calibration method across the range of interest and demonstrates the reliability of the NIR technique. The acquisition of a large number of international samples for final calibration of the master NIR HVI for micronaire, maturity, and fineness is well on its way to completion. In addition to acquiring more cotton samples, the next step will be to transfer the calibration equations generated in this research to different NIR HVIs and test the robustness of the equations.