Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2004
Publication Date: August 16, 2004
Citation: Byler, R.K. 2004. Development of a device for rapidly measuring cotton lint electrical resistance. Transactions of the ASAE. Vol. 47(4): 1331-1335. Interpretive Summary: The moisture content of cotton affects many aspects of the quality and value during storage, processing, and marketing. Gins focus on controlling cotton moisture content by adding and removing moisture. One property of cotton lint which can be used to measure its moisture content is the resistance of the fiber to the flow of electricity. Several devices are commercially available which use this property. However, the moisture content-resistance relationship is not well understood, especially the electrical resistance displayed during the first second after the instrument contacts the lint. In addition, the sample density affects the sample resistance. An instrument was constructed, calibrated, tested, and used to measure the cotton lint sample resistance. These data were used to develop an equation predicting the effect of changes in sample density and changes of sample moisture content as they relate to the sample electrical resistance. This information will allow engineers to design more useful cotton lint moisture sensors which can be used to better control the moisture content while ginning, and thus improve fiber quality.
Technical Abstract: The moisture content of cotton lint can be predicted from measurements of electrical resistance. New, automated, resistance-type moisture meters for cotton make measurements in less than a second. The sample resistance changes rapidly during the first 10 seconds of the measurement making conclusions based on older measurement technology which took several seconds questionable. Thus, a device capable of making measurements in less than a second was designed, built, calibrated, and tested. Data showed that the device could measure the electrical current through the samples precisely and that the current was related to the sample moisture content. The type of plastic tested for the sample holders did not affect the measured resistance. A strong relationship between the sample resistance and the sample density was found.