Sensing grain moisture content through dielectric properties

The rapid, nondestructive, reliable sensing of moisture content in cereal grains and other agricultural crops is essential in modem agriculture for prevention of losses and improvements in efficiency of production of these sources of food. Measurement, or sensing, of the relative complex permittivity, or dielectric properties, at microwave frequencies offers advantages that include density-independent sensing of moisture content. Recent research findings support the idea of a universal calibration, which would provide a significant advantage and should encourage the development of microwave moisture sensors for on-line applications for grain and other granular or particulate materials in agriculture and other industries.