Effects of "natural" water and "added" water on prediction of moisture content and bulk density of shelled corn from microwave Dielectric properties

U. S. Department of Agriculture, Agricultural Research Service, Richard B. Russell Agricultural Research Center, Athens, GA 30604-5677, USA.
The Journal of microwave power and electromagnetic energy: a publication of the International Microwave Power Institute (Impact Factor: 0.5). 01/2010; 44(2):72-80.
Source: PubMed


Dielectric properties of samples of shelled corn of "natural" water content and those prepared by adding water were measured in free space at microwave frequencies and 23 degrees C. Results of measurements of attenuation, phase shift and dielectric constant and loss factor at 9 GHz show no difference between the samples with "natural" water and those in which water was added artificially. Bulk densities and moisture contents predicted from calibration equations expressed in terms of dielectric properties of both natural and added water samples agreed closely, and standard errors were less than 1% for moisture content and relative error for bulk density was less than 5%.

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Available from: Micah A Lewis, Sep 21, 2015
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    • "This includes open coaxial probe, transmission line, free space and resonant cavity or cavity perturbation method [32]. Typically , the choice of dielectric property measuring technique depends on the nature of material (solid, liquid, powder), accuracy, material properties, sample size, contact or non-contact, frequency and temperature [32] [33]. Cavity perturbation technique is able to measure the dielectric properties for the most commonly used industrial frequencies (400–3000 MHz), in the temperature range from room to about 1400 °C [31], the size of the sample is small, and can handle low loss material [14] such as biomass, and therefore it was selected in this study. "
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