Journal of Biosystems Engineering

  • 제32권4호
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  • Pages.237-246
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  • 2007
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  • 1738-1266(pISSN)
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  • 2234-1862(eISSN)
한국농업기계학회 (Korean Society for Agricultural Machinery)
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분말식품의 마이크로파 유전율 및 수분함량 측정

Measurement of Permittivity and Moisture Content of Powdered Food at Microwave Frequencies

  • Kim, K.B. (Division of Metrology for Quality Life, Korea Research Institute of Standards and Science) ;
  • Kim, J.H. (Department of Radio Science and Engineering, Kwangun University) ;
  • Lee, J.M. (Department of Electronic Information Engineering, Yuhan College)
  • 발행 : 2007.08.25
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초록

In this study, the microwave free-space transmission technique was used to measure the dielectric property of powdered food at microwave frequencies. The sample holder was designed and fabricated to transmit the microwave signals ranging from 1 to 15GHz. From the microwave propagation theory the equation expressing the dielectric property of powdered food was derived and validated by standard dielectrics. The dielectric property of powdered food such as wheat flour, coffee powder and milk powder was measured and analyzed. In the uniform range of bulk density of material, the real parts of permittivity of the food samples increased with the increase of moisture content, bulk density and temperature of the samples. The propagation properties such as attenuation and phase shift increased linearly as the moisture density of the food samples increased. As a measuring frequency of the moisture content, the X-band was recommended.

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참고문헌

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