Microwave resonator technique for moisture content and mass determination in single soybean seeds

Principles are presented relating to the use of a microwave resonant cavity for determining simultaneously the mass and moisture content of individual soybean seeds. Measurement of the resonant frequency shift and change in the transmission characteristics of the cavity when the soybean seed is inserted provides the necessary information for calculating the mass of water in the seed and the dry matter mass, from which the moist mass of the seed and its moisture content can be determined. Uncertainties of the measurements of mass and moisture content were 3 percent and less than 1 percent moisture content, wet basis, respectively, at the 95-percent confidence level