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United States Department of Agriculture

Agricultural Research Service

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Location: Quality and Safety Assessment Research Unit

Project Number: 6612-44000-027-00
Project Type: Appropriated

Start Date: Sep 15, 2009
End Date: Oct 25, 2010

To identify relationships between dielectric properties of agricultural products and their important quality characteristics and to develop sound scientific principles for measuring these characteristics through interaction of radio-frequency and microwave electromagnetic fields with the products. Emphasis will be placed on development of improved technology for reliable, accurate moisture sensing in cereal grains and their products applicable to on-line measurement and monitoring of moisture content.

Laboratory mesurements on grain and seed samples, computation of dielectric properties, and analyses of resulting data, including suitable graphical techniques, will be performed on several kinds of grain and seed of economic importance. Variables will include kind of grain or seed, frequency used, moisture content, temperature, and bulk density of the grain or seed sample. Resulting data will be studied to determine behavior of the dielectric properties with respect to all variables, and results will be examined to verify relationships between and among the variables to determine whether or not behavior is in agreement with known principles or previous observations. The testing of density-independent calibration functions of the dielectric properties for their success in predicting moisture content of the various kinds of grain and seed, independent of bulk density, will be conducted. Data acquired at selected frequencies will be evaluated to identify advantages of certain frequency ranges for practical moisture sensing for each of the grain types being studied. In parallel with the moisture sensing, performance of measurement systems in sensing the bulk densities of the different kinds of grain and seed will also be assessed. The indicated universal character of the best density-independent calibration function for predicting moisture content of the different kinds of grain and seed will be tested on additional granular materials to determine the degree of its universal character. Desired characteristics for practical moisture sensors will be determined and prototype moisture meters will be developed and tested to demonstrate feasibility so that private industry can be interested in commercial development.

Last Modified: 9/10/2014
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