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International Agrophysics
wydawca:Instytut Agrofizyki
im. B. Dobrzańskiego
PAN
w Lublinie
ISSN: 0236-8722


vol. 19, nr. 3 (2005)

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Utilization of electric properties of granular and powdery materials
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Z. Hlaváčová
Department of Physics, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic

vol. 19 (2005), nr. 3, pp. 209-213
streszczenie Determination of electrical properties is utilized in a wide range of disciplines and industries. A brief compendium of electrical properties utilization of granular and powdery agricultural and food materials is presented in this paper. Electrical properties of granular and powdery materials are influenced by various factors. The most important are moisture content and its distribution in materials, temperature, density, volume or bulk density. The relationships between the resistivity, conductivity, capacitance, relative permittivity and various influencing factors are described. The electrical conductivity measurements are utilized in the determination of the salinity of soils and irrigation water. Biological material properties are determined from their leachates, too. The conductivity measurements are applied for the determination of various characteristics of agricultural materials and foods (frost sensitivity, chilling and freezing tolerance, moisture content, seed germination, mechanical stress). Investigated materials are very various, for example grains, seeds, meat, sugar, milk, wood, soil, fruit and vegetable, infected food. The utilization of dielectric properties is also described; for example in agricultural materials and food quality sensing (moisture content, maturity of fruit, potential insect control in seeds, radio frequency heating). The classification of permittivity measurement techniques is mentioned.
słowa kluczowe electrical properties, resistivity, relative permittivity