APPLICATION OF A RESISTANCE MOISTURE METER TO HVI STRENGTH MEASUREMENTS
Transactions of the ASAE
Agriculture as part of the classification of cotton. The moisture content (m.c.) of fiber and of the testing atmosphere is known to affect the strength of individual cotton fibers (Moore and Griffin, 1964) and the fiber strength measurements (Lawson et al., 1976) , among others. Wilde (1990) showed that corrections based on a relative humidity measurement could substantially reduce uncontrolled variation of HVI strength due to atmospheric changes. The U.S. Cotton Ginning Laboratory (USCGL) has
... ratory (USCGL) has developed (Byler, 1998) and patented (Byler and Anthony, 1996) a new resistance moisture meter which is fast, accurate, and reasonably inexpensive. Presumably a measurement of the m.c. of cotton fibers made during fiber strength testing could be used to reduce the variability in strength measurement results due to the moisture content variation (Byler et al., 1993) . Resistance moisture measurements could be added to the HVI strength measurement system if the moisture meter were fast and accurate enough. The moisture content data could potentially be used to mathematically correct the strength readings to a standard moisture content or to simply indicate to the operator that a sample was not within an acceptable moisture range. PURPOSE The purpose of this study was to examine relationships between fiber moisture as measured by the newly developed moisture meter and HVI strength and to gain experience in using the meter under commercial conditions. ABSTRACT. A series of four studies were conducted with the assistance of two U.S. Department of Agriculture Agricultural Marketing Service offices to determine the range of fiber moisture encountered in cotton classing and to examine the potential of using on-line moisture readings to assist with fiber strength readings. These studies showed that the meter could be used with the existing high volume instrument (HVI) cotton classing equipment and that the measured moisture content (m.c.) correlated with the HVI strength, as it should. The first study, conducted at the Memphis Quality Control Section, demonstrated the usefulness of the resistance moisture meter and showed a strong relationship between measured m.c. and HVI strength. The second study was conducted at the Greenwood, Mississippi, Classing Office (CO) during the regular classing season to determine if the meter could operate under CO production conditions and determine the range of moisture contents which must be measured. The meter functioned well during the classing season. The measured m.c. of cotton samples was found to have a greater range than expected during classing and was directly proportional to the HVI strength. Ninety-four percent of the samples were within the range of 6.3% to 7.6% wet basis (w.b.) but the entire observed range was 5.8% to 10.0% w.b. The third study was conducted at the Greenwood CO on samples prepared at the U.S. Cotton Ginning Laboratory, USDA, ARS, Stoneville, Mississippi, and ginned under several moisture treatments. Ginning machines and post-ginning moisture treatment affected the fiber m.c. relatively little, but a significant reduction in strength was attributed to ginning at m.c. below 7% w.b. The fourth study was conducted at the Greenwood CO where samples were subjected to nonstandard moisture conditions and then HVI classed. This study showed that even when the m.c. variation measured by the experimental meter was low (0.3% w.b.) there was a measurable effect on HVI strength. All four studies resulted in a significant correlation between the measured m.c. and the measured HVI strength showing that the resistance moisture meter is a promising addition to the HVI classing line.