Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Proceedings
Publication Acceptance Date: 7/21/1999
Publication Date: N/A
Technical Abstract: Dielectric methods are commonly used for moisture content determination in powdered and granular materials. Because of bulk density fluctuation while performing moisture measurements, its effect has to be taken into account in the final output of the moisture meter. One possible solution is the use of density-independent calibration functions. In this paper, a method is presented for the generation of such functions from representations of the complex permittivity of these materials in the complex plane. Results at two microwave frequencies, 11.3 GHz and 18.0 GHz, are discussed for hard red winter wheat with densities ranging from 720 to 880 kg per cubic meter over the moisture content range of practical interest at room temperature. The purpose of the study is to select optimum conditions for the development of accurate nondestructive moisture sensors by defining appropriate density-independent calibration functions.