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Electrical Characterization of Non-Conducting
Materials Using Reflection Based Microwave
Technique
B Y
PAL L AV I M AL AM E ( T P 2 F 1 2 1 3 0 0 1 )
G U I D E
D R . R AJ I V G U P TA
Submitted in partial fulfilment of the
requirements
of the degree of
Master of Engineering
by
Pallavi R. Malame
TP2F1213001Supervisor:
Dr. RAJIV K. GUPTA
27-02-2015 TERNA COLLEGE : ME THESIS 2
ACKNOWLEDGEMENT
Dr. R. K. Gupta, HOD , EXTC Department,
Dr. Deven Shah, Principal.
Mr. Rajesh Harsh (Scientist F), HOD, Technology Innovation Dept.(TID), SAMEER
Mr. Anil Kulkarni (Scientist F) ,HOD, Industrial Meteorological and System Dept. (IMSD), SAMEER
Mr. Tapas K. Bhuiya (Scientist D), IMSD , SAMEER
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Introduction
Microwave Reflectometry
Features of FDR
Motivation
Problem Statement
Objectives
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Motivation
Society for Applied Microwave Electronics Engineering & Research
Department of Electronics and Information Technology
Under the aegisof
Core Project : Moisture Measurement System
Brix Measurement for Sugar Industry
}
My Role
Problem Statement
• Need for accurate, rapid measurement system which can be used for in-situ, online measurements
• a research study is needed in the field of dielectric spectroscopy
• Exploration of Reflection based method• Exploration of Transmission/Reflection based
method• Analysis of permittivity of wide variety of materials
(liquid-semi solids-solids) using Microwaves
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ObjectivesTo electrically characterize variety of liquids like oils, sugar solution, honey and milk using open ended coaxial cable technique (simulation as well as experimentally) which is a reflection based microwave method.
To electrically characterize variety of solids like substrates and wood using waveguide fixture method (simulation as well as experimentally) which is based on Transmission/Reflection based method.
To explore other dielectric spectroscopy techniques
How did I achieve this
??
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Microwave Reflectometry
Time domain reflectometry - TDR
Frequency domain reflectometry - FDR
• Less expensive • More accurate• Advantage of
Calibration
FDR Features:• gives high accuracy• for homogeneous materials• fast replacing laborious and time-
consuming physical and chemical laboratory analytical methods
• applicable to materials and products of agricultural origin
• non-destructive and rapid measurements
• applications using automation• Ideal for in-situ/in vivo online
measurement systems• influence of electrical conductivity is
negligible• penetration depth is much greater• continuous remote monitoring• insensitive to environmental factors• enabling detection of even small
amounts of water• Do not pollute the tested material
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Electrical Characterization of Non-Conducting Materials Using Reflection Based MicrowaveTechnique
Electrical Characterization Non-Conducting Materials Reflection Based Microwave Technique
Figures Just for Illustration Purpose
Non Magnetic materials Products
Measuring Electrical Parameter only: Dielectric
S11ReflectionS21TransmissionEr’Dielectric ConstantEr’’ Loss Factor
C Band ( 5.81 GHz)
Why 5.81??
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Literature survey• Polar dielectrics and modelling studies date back more than 70 years reported by
Debye in 1929.• In the last 10-15 years, the concept of permittivity measurement has been extended
and applied to various agricultural, food, and biological problems• 1945 - carrots at frequencies in the range of 18 kHz to 5 MHz by Dunlap and Makower.• 1949 - potato, carrot, apple, and peach tissue from 1 to 40 MHz by Shaw and Galvin• 1984 - tabulated the dielectric properties of selected vegetables and fruits at a
frequency range 0.1 to 10 GHz by tran et al.• 1980 - moisture content on the dielectric properties of granular solids at 9.4 GHz over
a wide range of temperature and moisture contents by M.A. Stuchly, and S.S. Stuchly• Several techniques to measure the dielectric properties of agri-food materials are
described in 1) Handbook of Microwave Measurements by M. Sucher and J. Fox2) Industrial Microwave Heating by A.C. Metaxas and R. Meredith
• 1980 -The dielectric properties of food materials in the microwave region can bedetermined by several methods using different microwave measuring sensors [22-23]Microwave aquametry by A.W. Kraszewski.
• 1989 - Nyfors and Vainikainen [24] has reported four groups of measurementmethods, namely, lumped circuit, resonator, transmission line, and free-spacemethods.
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Open ended Coaxial Method• 1980 - Open ended coaxial probe method has been reported by Stuchly and Stuchly• 1989 - For liquid and semi-solid materials, including biological and food materials, open-
ended coaxial-line probes have been used for broadband permittivity measurements.Grant et al and Blackham et al.
• For liquid and semi-solid materials, including biological and food materials, open-endedcoaxial-line probes have been used for broadband permittivity measurements [25-26].
• A similar technique is used for permittivity measurements on fresh fruits and vegetablesby Nelson.
Oils• 2008 -Dielectric properties of vegetable oils and fatty acids in low frequencies (0.1-1
MHz) are studied by Lizhi et al.• 2010 - On the basis of this research it is possible to detect whether olive oil has been
adulterated with cheaper vegetable oil [29].• 2010 - Latest studies based on TDR have been reported by Piuzzi et al [30]MilkUse of open ended coaxial probe technique for dielectric property measurement ofmilk is mentioned in Advanced Dairy Chemistry by McSweeney
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• 1974 - Mudgett et.al.[32] has observed dielectric properties of skim milk over thetemperature range 25-55oC.
• 2006 - Nunes et al. [33] has examined the complex dielectric permittivity of UHT milk in afrequency range 1-20 GHz.
• 1992 & 2010 - Latest studies are reported by Kudra et al [34] and W Guo et al [35].Honey• 2010 - Study of honey using open ended coaxial cable has been reported by W Guo et al.
Dielectric spectroscopy is used for determining difference between different honey andsucrose and water content of honey [36-37].
Waveguide Fixture• Microwave measurement systems to determine the dielectric properties of grain, Early
efforts to characterize the dielectric properties of materials using transmission/reflectionbased method which are open resonant structures are fabricated at the MassachusettsInstitute of Technology [11, 38].
• 1973,1983,1984 - Coaxial-line and rectangular wave-guide sample holders are used withvarious mid, and fruit and vegetable tissue samples at frequencies from 1 to 22 GHz [8,39-41].
• 1983 -The sample holders are also used to measure dielectric properties of pulverized coaland mineral samples [40].
• 1970 - Dielectric properties of grain samples are measured using a precision bridge overaudio frequencies from 250 Hz to 20 kHz with sample holders confined in a coaxial sampleholder and reported in [42].
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Permittivity and Dielectric Mechanism
"'
0
rrrj
'
"
tanr
r
r
'
r
''
r
Complex RelativePermittivity
Dielectric Constant
Loss Factor
Loss Tangent
Complex Permittivity: Permittivity describes the interaction of a material with an electric field.Dielectric Constant :It is a measure of how much energy from an external field is stored in a material.Loss Factor: It is a measure of how dissipative or lossy a material is to an external field.Loss Tangent: The loss tangent or tan δ is defined as the ratio of the imaginary part of the dielectric constant to the real part.
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Dielectric Theory
"'rrr j "'
rrr j
Electric Magnetic
Permittivity Permeability
FieldsFields
STORAGE
LOSS
MUT
STORAGE
LOSS
Non Magnetic Material!
1
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Interaction of Medium with EM Waves
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Dielectric Mechanism
Random Motion of water molecules
Orientation in Electromagnetic Field
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Frequency response of Dielectric Mechanisms
Microwave frequency region
} Microwave frequency
Loses are introduced at low frequency
Parameters contributing to permittivity
Conduction: ionic
Dipolar relaxation
Atomic polarization
Electronic polarization
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Return
Relaxation time
11
10
100
10 100
Water at 20o C
f,
GHz
most energy is lost at 1/t
'r
"r
Cole Cole Plot
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Measurement Techniques
Parallel Plate Low Frequency
Best for thin flat sheets
Coaxial Probe Broadband
Best for liquids, semi-solids
Transmission Line Broadband
Best for machine-able solids
Transmission Free Space
Broadband, mm-wave
Non-contacting
Resonant Cavity Single frequency
High accuracy, Best for low loss, or very thin samples
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Vector Network Analyzer
N5221A PNA.
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Image Courtesy : Agilent Technologies
Reflection based Electrical Characterization of Non-Conducting Materials.
Sensor Probe, waveguide, patch antenna
Measured parameter S11 reflection coefficient
Features:
Best for lossy MUTs, liquids or semi-solids.
Broadband.
Convenient and non-destructive.
Require no machining of the sample, easy sample
preparation, after
calibration, the dielectric properties of a large number of
samples can be
routinely measured in a short time.
Measurement can be performed in a temperature controlled
environment.
27-02-2015 TERNA COLLEGE : ME THESIS 20
Transmission/Reflection based Electrical Characterization of Non-Conducting Materials.
Sensor waveguide
Measured parameter S11 and S21
Features:
• Accuracy
• Best for solid materials.
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Open Ended Coaxial Probe Technique
Sample thickness
d
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Practical ViewCalibration and Measurement Technique
• Agilent Technologies N5221A PNA network
analyser
• Agilent Technologies 85070E open ended coaxial-line probe
• 85070E software• reflection coefficient was measured• PNA Port OSL calibration • Probe Calibration open, short and deionised
water • Temperature maintained at 250C• Ecal Module
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Oils
Result And Discussion
Sample oils:50 ml coconut oil50ml groundnut oil50ml sunflower
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ε’
Low Frequency
ε"
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Brix
Result And Discussion
Sample: 100g Water and Sugar Solution
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Sugar content ε’ ε"σ : conductivity
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Milk
Result And Discussion
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Milk Adulteration Detection
Sample: Fresh untreated cow’s milktemperature is maintained at 250Cadulterants used are:water at room temperature, sugar, wheat flour as starch and sodium bi carbonate
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Image Courtesy: Times of India (6/3/14)
ε’’ε’
Water
Water
ε’’
Water
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Dielectric Response
Sugar
ε’
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ε’
ε’’
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Honey
Result And DiscussionA sample of honey from an apiary belonging to apis indica species of honeybee
Adulterants:distilled water and
corn syrup.
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ε’
Water
ε’’
Water
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ε’
cornsyrup
ε’’
cornsyrup
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Rectangular Waveguide as Fixture: Simulation in HFSS
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S11 vs Frequency
S11= -19.927 at 5.81GHz
SIMULATION RESULTS
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Experimental Setup
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Coax to Waveguide Adaptor
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SAMPLE HOLDER AND SAMPLE
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85071E Software
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Waveguide Fixture S11 S21
Coax to waveguide adapter 1 -21.79dB -
Coax to waveguide adapter 2 -25.85dB -
Combined waveguide -24.85dB -0.94dB
Material
Teflon 2.1 2.53
UHM 2.4 2.66
Wood 1.2-5 5.43
Wet-Wood - 12.58
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Frequency 5.71GHz
0.2
0.1
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Conclusion
The experimental results on oil and brix content are close to the values specified in Literature and Theory
Open ended coaxial technique can be utilised for oil adulteration detection-More experimentation with TDR required
The Technique can satisfactorily used in Sugar Industries for measurement of brix due to wide variation in S11 data
Milk and Honey adulteration detection methods are proved reliable and accurate
Transmission/Reflection based method using software 85071E gives a very accurate
Result compared to reflection based method. The fabricated waveguide design proves very useful in wood, paper and pulp industries for wood moisture measurement for instant results
27-02-2015 TERNA COLLEGE : ME THESIS 48
Scope for Future Work
Dielectric spectroscopy of oil
Investigations for fat content measurement
Cheese Industry
Instead of Rectangular waveguide a circular waveguide can be used.
More materials like metamaterials can be studied for their dielectric and magnetic property
Different sensors including Patch antennas ,horn antennas etc. can be explored.
27-02-2015 TERNA COLLEGE : ME THESIS 49
27-02-2015 TERNA COLLEGE : ME THESIS 50
References[1] W. Skierucha; A. Wilczek, and A. Szyplowska, “Dielectric spectroscopy in agro
physics”, Int. Agrophys., pp. 187-197, 2012.
[2] T.W. Athey, M.A. Stuchly and S.S. Stuchly, “Measurement of radio-frequency
permittivity of biological tissues with an open-ended coaxial line - Part I”, IEEE
Transactions on Microwave Theory and Techniques, vol. 30 ,no.1, pp.82-86. 1982.
[3] D. Bérubé, F.M. Ghannouchi, and P. Savard, “A comparative study of four open-ended
coaxial probe models for permittivity measurements of lossy dielectric biological
materials at microwave frequencies”. IEEE Transactions on Microwave Theory and
Techniques, vol. 44, no.10, pp. 1928-1934, 1996.
[4] M.M. Brady, S.A. Symons, and S.S. Stuchly, “Dielectric behaviour of selected animal
tissues in vitro at frequencies from 2 to 4 GHz”, IEEE Transactions on Biomedical
Engineering, vol. 28, no.3, pp.305-307, 1981.
[5] R. ZAJÍČEK, L. OPPL, J. VRBA, “Broadband Measurement of Complex Permittivity
Using Reflection Method and Coaxial Probes”,Technická 2, Prague.
[6] Xiong Yu, Vincent P. Drnevich, and Robert L. Nowack Ref.: Yu, Xiong, Drnevich,
Vincent P. and Nowack, Robert L., “Improvements of Soil Dielectric Mixing Model for
Inversion Analysis of Time Domain Reflectometry Measurements", Proc. TDR 2006,
Purdue University, West Lafayette, USA, vol 4, pp.19 , Sept. 2006.
. New York, NY: The Chemical Catalog Company. 1929.
27-02-2015 TERNA COLLEGE : ME THESIS 51
[7] Scott B. Jones, Jon M. Wraith and Dani or, “Time domain reflectometry measurement
principles and applications” Hydrol. Process., Vol 16, pp.141–153, 2002.
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applications”, IEEE Transactions of Electrical Insulation, vol. 26, no.5, pp.845-869.
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[9] J. W. Choi, J. Cho, Y. Lee, J. Yim, B. Kang, K. Oh, et al., “Microwave detection of
metastasized breast cancer cells in the lymph node; potential application for sentinel
lymphadenectomy,” Breast Cancer Research and Treatment, vol. 86 , no.2, pp. 107-115,
2004.
[10] P. Debye, Polar Molecules. New York, NY: The Chemical Catalog Company. 1929.[11] A. Von Hippel, Dielectrics and Waves. New York, NY: John Wiley and Sons. 1954.[12] S.O. Nelson, “Dielectric properties measuring techniques and applications”, ASAE,No. 983067. St. Joseph, MI: ASAE. 1998.[13] W.C. Dunlap,and B. Makower, “Radio frequency dielectric properties of dehydratedcarrots”, Journal of Physical Chemistry , vol. 49: pp. 601-622, 1945.[14] T.M. Shaw, and J. A. Galvin, “High frequency heating characteristics of vegetabletissues determining from electrical conductivity measurements”, In ProceedingsInstitution of Radio Engineering, Institute of Radio Engineering and ElectronicsPublication, Chaberska, Prague: IREE, vol. 37, pp. 83-86. 1949.[15] W.E. Pace, W.B. Westphal and S.A. Goldblith. “Dielectric properties of commercialcooking oils”, Journal of Food Science, vol. 33, pp. 30-36, 1968.[16] V.N. Tran, S.S. Stuchly and A.W., “Kraszewski. Dielectric properties of selectedvegetables and fruits at 0.1 - 10 GHz”, Journal of Microwave Power, vol. 19, no.4, pp.
27-02-2015 TERNA COLLEGE : ME THESIS 52
[17] M.A. Stuchly, and S.S. Stuchly, “Dielectric properties of biological substances –Tabulated”, Journal of Microwave Power, vol. 15, pp.19-26,1980.[18] M. Sucher and J. Fox, Handbook of Microwave Measurements. New York, NY:Polytechnic Press Institute. 1963.[19] G.P. de Loor, and F.W. Meijboom, “The dielectric constant of foods and othermaterials with high water contents at microwave frequencies”, Journal of FoodTechnology, vol. 1, pp.313-322, 1966.[20] N.E. Bengtsson, and P.O. Risman, “Dielectric properties of food at 3 GHz asdetermined by a cavity perturbation technique. II. Measurements on food materials”,Journal of Microwave Power, vol. 6 , no.2, pp. 107-123, 1971.[21] A.C. Metaxas and R. Meredith. Industrial Microwave Heating (IEEE PowerEngineering Series). Piscataway, NJ:Peter Peregrinus. 1983.[22] A.W. Kraszewski, “Microwave aquametry - A review”, Journal of Microwave Power,vol. 15, no.4, pp. 209-220, 1980.[23] A. Kraszewski, Microwave Aquametry – Electromagnetic Interaction with WaterContaining Materials, Piscataway, NJ: IEEE Press. 1996.[24] E. Nyfors, and P. Vainikainen, Industrial Microwave Sensors, chapter 2. Boston, MA:Artech House, Norwood. 1989.[25] J.P. Grant, , R.N. Clarke, G.T. Symm and N.M. Spyrou, “A critical study of the openendedcoaxial line sensor technique for RF and microwave complex permittivity measurements”, Journal of Physics: Electronics and Scientific Instrument, vol. 22, pp.757-770, 1989.
27-02-2015 TERNA COLLEGE : ME THESIS 53
[26] D.V. Blackham, and R.D. Pollard, “An improved technique for permittivitymeasurements using a coaxial probe”, IEEE Transactions of Instrumentation andMeasurement , vol. 46 , no. 5, pp.1093-1099. 1997.[27] S.O. Nelson, “Measurement of microwave dielectric properties of particulatematerials”, Journal of Food, 1994.[28] H. Lizhi, K. Toyoda, and I. Ihara, “Dielectric properties of edible oils and fatty acidsas a function of frequency, temperature, moisture and composition,” J. Food Eng., vol.88, pp. 151–158, 2008.[29] H. Lizhi, K. Toyoda, and I. Ihara, “Discrimination of olive oil adulterated withvegetable oils using dielectric spectroscopy,” Journal of Food Engineering, vol. 96, pp.167-171, 2010.[30] A. Cataldo, E. Piuzzi, G. Cannazza, E. De Benedetto, and L. Tarricone, “Quality andanti-adulteration control of vegetable oils through microwave dielectric spectroscopy,”Measurement, vol. 43, no. 8, pp. 1031-1039, 2010.[31] Paul L. H. McSweeney, Patrick F. Fox ,Advanced Dairy Chemistry: Volume 3:Lactose, Water, Salts and Minor Constituents[32] R.E. Mudgett , S.A. Goldblith, D.I.C. Wang and W.B. Westphal, “Dielectricbehaviour of semi-solid food at low, intermediate and high moisture contents”, Journalof Microwave Power, vol .15, no.1, pp. 27-36. 1980.[33] A C Nunes, X Bohigas, J Tejada, “Dielectric study of milk for frequencies between 1and 20 GHz”, Journal of Food Engineering ,vol.76, no. 2, pp. 250–255, 2006.[34] T Kudra, G S V Raghavan, C Akyel, R Bosisio, F R Voort, “Electromagneticproperties of milk and its constituents at 2.45 MHz”, Journal of Microwave Power andElectromagnetic Energy, vol. 27 , no.4 , pp. 199–204,1992.
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[35] W Guo, X Zhu, H Liu, R Yue, S Wang, “Effects of milk concentration and freshness on microwave dielectric properties”, Journal of Food Engineering, vol. 99, pp. 344-350,2010.[36] W Guo, X Zhu, Y Liu, H Zhuang ,Sugar and water contents of honey with dielectric property sensing, Elsevier: Journal of Food Engineering, vol. 97, no. 2, pp. 275–281 , March 2010.[37] W Guo, Y Liu, X Zhu, S Wang, “Dielectric properties of honey adulterated withsucrose syrup”, Elsevier: Journal of Food Engineering, Vol. 107, no.1, pp. 1-7, 2011.[38] S. Roberts, and A. von Hippel, “A new method for measuring dielectric constant andloss in the range of centimetre waves”, Journal of Applied Physics, vol. 17, pp.610-616,1946.[39] S.O. Nelson, “Electrical properties of agricultural products - A critical review”,Transactions of the ASAE , vol.16, no. 2, pp. 384- 400, 1973.[40] S.O. Nelson, “Density dependence of the dielectric properties of particulate materialspulverized coal, flour, wheat samples”, Transactions of the ASAE , vol.26, no.6 ,pp.1823-1825, 1983.[41] S.O. Nelson, “Moisture, frequency, and density dependence of the dielectric constantof shelled, yellow-dent field corn”, Transactions of the ASAE , vol. 30, no. 5, pp. 1573-1578, 1984.[42] P.T. Corcoran, S.O. Nelson, L.E. Stetson and C.W. Schlaphoff, “Determiningdielectric properties of grain and seed in the audio frequency range”, Transactions of theASAE , vol.13, no.3 , pp.348-351, 1970.[43] Agilent, 2006. Basics of measuring the dielectric properties of materials. ApplicationNote:32, USA.
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[44] D.M. Slaten,; B.N. Scott,; Gordon, B. Lloyd, “ Techniques and applications ofpermittivity measurements”, Electrical Insulation and Dielectric Phenomena, IEEE1996 Annual Report of the Conference, Vol. 1 , pp. 94 – 97, 1996.[45] L.F. Chen, C.K. Ong, C.P. Neo, V.V. Varadan, and V.K. Varadan, “MicrowaveElectronics Measurement and Materials Characterization”, John Wiley & Sons Ltd,England, pp. 119-123, 2004.[46] L. OPPL, Measurement of Dielectric Properties. Dissertation Thesis, CTU in Prague,Dept. of EM field, 2001. (in Czech)[47] F. Harding, (Ed.) (1995), Chapter 5: Adulteration of milk. Chapter 6: Compositionalquality. In: Milk Quality. Blackie Academic & Professional, London.[48] Laleh Mehryar, Mohsen Esmaiili, Honey & Honey Adulteration Detection: A Review,In proceeding of: 11th International Congress on Engineering and Food (iCEF11),Athens, Greece, Vol. 3, 2011[49] G.F. Miner, Lines and Electromagnetic Fields for Engineers, Oxford University Press,pp.741, 1996.61[50] Agilent 85071E, Materials Measurement Software : Technical Overview Published inUSA, June 14, 2012
Thank You
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