A device for rapidly predicting cotton lint moisture content

The moisture content (MC) of cotton lint can be predicted from measurements of electrical resistance. New, automated, resistance-type moisture meters for cotton make measurements in less than 1 s using DC excitation. The sample resistance changes rapidly during the first 10 s 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 1 s and using DC excitation 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. Regression analysis showed that the standard error in predicting MC was 0.20% over the range 4.1% to 8.7% (wet basis). The types of plastic tested for the sample holders did not affect the resistance. A strong relationship was found between the sample resistance and the sample density over the range of 0.4 to 1.4 g/cm(3).