Nondestructive microwave characterization for determining the bulk density and moisture content of shelled corn

A method based on nondestructive microwave characterization is used for simultaneous determination of the bulk density and moisture content of shelled corn. This method can be applied regardless of the measurement technique and thus considerably simplifies the calibration procedure. Calibration equations, both for the bulk density and for the moisture content, are given, together with the standard error of performance (SEP) at several frequencies in the range 11-18 GHz and three temperatures, 14, 24 and 34 degrees C. The bulk density, ranging from 695 to 830 kg m(-3), can be determined with SEP in the range 11-15 kg m(-3) Neither the sample moisture content nor its temperature are required in order to determine the bulk density. The moisture content ranging from 9% to 19% on a wet basis, can be determined at each temperature without knowledge of the bulk density with SEP of less than 0.5% moisture content. Results of an error analysis of the measurements show that about half of the total uncertainties in bulk density and moisture content can be considered systematic errors and thus they are correctable.