Technical Note: Cotton Bale Moisture Meter Comparison at Different Locations

Seven commercially available portable cotton bale moisture content (mc) meter-probe combinations were purchased by each of the three Agricultural Research Service Cotton Ginning Research Units and examined for precision and accuracy when used with commercially ginned cotton. The devices were used to measure the mc at the same six locations on a total of 96 cotton bales. Lint samples were obtained from the same locations in the bales for mc determination by the oven method resulting in more than 7000 meter readings with corresponding reference mc values. Based on oven-mc, the lint samples had mc in the range 2.3% to 9.4% wet basis. The oven-mc wet basis for the different samples in the same bale had a standard error from 0.15% to 0.42% wet basis. The different meters produced significantly different readings from each other, and these were significantly different from the oven-based mc. Most of the meters were found to have a significant offset from the oven-based mc ranging from -3.3 to 3.3 percentage points. However, the standard deviation of the difference between the individual readings of the meters and the oven-based mc resulted in estimates of precision of plus or minus one percentage point for most of the individual meters.