A Method for Determining the Dielectric Properties of Grain and Seed in the 200- to 500-MHZ Range

This research was undertaken to extend the radiofrequency range of reliable dielectric properties determinations for grain and seed above250 MHz using a General Radio 1602-B Admittance Meter. The purpose of this research was to develop a reliable method for determining the dielectric properties of a high-loss heterogeneous material such as grain. Several methods or instruments are commercially available for measuring dielectric properties of low-loss homogeneous materials such as liquids or solids. Thus, for high-loss heterogeneous materials, the methods, sample sizes, or techniques must be modified to accurately determine the dielectric properties. With the availability of the General Radio 1602-B Admittance Meter for measurement of a wide range of admittance values, the problem remaining was to select a method for determining the dielectric properties, design a suitable sample holder, and obtain the necessary measurements. A frequency range of 200 to 500 MHz was selected for this research since it overlaps by 50 MHz the method developed by Jorgensen for comparison purposed and it doubles the frequency range now covered by the other two methods. Advisor: S. O. Nelso