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United States Department of Agriculture

Agricultural Research Service

Title: Advances in Sensing Grain Moisture Content by Microwave Measurements

Authors
item Nelson, Stuart
item Trabelsi, S - OICD
item Kraszewski, Andrzej

Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 16, 1997
Publication Date: N/A

Interpretive Summary: Moisture content of grain is one of the most important characteristics determining the length of time that grain can be safely held or stored without spoilage. Therefore, moisture content must be measured at harvest and whenever grain is sold. The selling price is affected by moisture content, not only because the costs for drying must be considered, but also obecause the water in the grain has less value than the grain dry matter. Since the dielectric properties (electrical characteristics) of grain are highly correlated with its moisture content, electronic grain moisture testers have been developed that provide quick moisture tests. However, samples from grain lots must be taken judiciously and then tested to obtain reliable moisture information on the whole grain lot. Recent research has shown that microwave measurements should be useful for monitoring moisture in flowing or moving grain. Recent advances in the use of microwave measurements for sensing moisture content are described that provide reliable moisture data even though the bulk density or packing of the grain may fluctuate while flowing. The techniques described offer promise for the development of useful grain moisture sensing instruments for on-line grain moisture monitoring. This would help system managers in preserving grain quality and improving quality in processed grain products. When implemented, the moisture monitoring techniques will help to maintain the competitive advantage of American producers in the global market.

Technical Abstract: Basic principles of grain moisture sensing by microwave measurements are presented, including the techniques for moisture content determination independent of bulk density. Results are briefly summarized for recent findings with respect to the performance of microwave measurement techniques for density-independent moisture sensing in grain that should provide a sound basis for development of microwave moisture meters for on-line applications.

Last Modified: 4/23/2014
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