Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 3, 2003
Publication Date: December 18, 2003
Citation: Byler, R.K. 2003. Effect of specimen size on cotton lint moisture content by the oven method. Applied Engineering in Agriculture. 20(1): 5-9. Interpretive Summary: The moisture content of cotton fiber is very important in the processing of cotton. The fiber moisture content is normally determined by comparing the weight before and after drying approximately 20 gram specimens in an oven. Three to five specimens are averaged for each value for a total of 60 to 100 grams. When the amount of cotton fiber is limited the standard oven-drying method of determining moisture can consume a considerable portion of the fiber which is needed for testing other factors. This study was undertaken to examine if and how 1 gram specimens could be used instead of 20 gram specimens. Results indicated that 1 gram specimens produced the same average moisture content as 20 gram specimens. Seven 1 gram specimens gave the same moisture content value with the same accuracy as three 20 gram specimens, thereby consuming only 12% as much fiber. When fiber quantity is limited, 1 gram specimens can be used for moisture determination instead of 20 gram specimens. The 1 gram procedure will greatly increase the ability of cotton researchers to focus on improving fiber quality.
Technical Abstract: Proper assessment of the moisture content of cotton lint is critical to all phases of cotton processing. Traditional methods of moisture content determination require multiple 20 gram specimens of lint which is more than is available on many occasions, especially when the moisture content mean is required to achieve an acceptable standard deviation. Thus, the use of smaller specimens was considered. Cotton lint specimens of 1 gram, 5 gram, 10 gram, and 20 gram were taken from lots conditioned to different moisture content levels and the moisture content determined by the oven method. The results indicated that the mean moisture content based on 1 gram specimens was the same as that based on 20 gram specimens. Based on the variance of the moisture content data separated by specimen size and drying time, seven 1 gram specimens produced the same variance as three 20 gram specimens after 1 h of oven drying. Therefore, 1 gram specimens can be used for oven-based moisture content determination instead of 20 gram specimens, consuming considerably less lint material. The procedure to determine moisture content based on 1 gram specimens required more time and effort as well as more specimens to achieve a similar variance so the 1 gram sample procedure should only be used when material is limited.