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Fig. 14. Fig. 15. Fig. 16. Fig. 17. Fig. 18. Fig. 19. Fig. 20. Fig. 21. Fig. 22. Fig. 23. Fig. 24. Fig. 25. calculated from 3-phase model α (27) for different values of α parameter. ............................................................................................38 Comparison of the soil dielectric constants measured by TDR method (horizontal axis) and calculated by the empirical model (31) accounting for soil bulk density...................................................39 Values of dielectric constant of bound water, ε bw , related to the distance, x, from the phases interface..................................................40 Effects of the 4-phase models for the investigated clay soils (Table 6, no. 10 and 11): A – for model α, B - for de Loor model and C – effect of regression model (31) accounting for soil bulk densities, the solid line represents model (31) for ρ = 1,42 [gcm -3 ]....40 Comparison of the analysed soil dielectric constant measured by TDR method (horizontal axis) and calculated from the 4-phase model α ...............................................................................................41 The experimental setup for the determination of temperature effect on soil dielectric permittivity determined by TDR method.......44 Block diagram of the laboratory setup for the determination of temperature effect on soil dielectric permittivity ................................45 Block diagram of the TDR probe with the electronics for soil electrical conductivity and temperature measurements.......................46 Application window presenting the state of the conducted experiment...........................................................................................47 Set of reflectograms registered by the presented setup for the same soil sample in different temperatures. ........................................48 The effect of the applied temperature corrections for TDR measurement in water: (43) – for the measured refractive index, n (part A), and (46) – for the calculated volumetric water content, θ TDR (part B).........................................................................................58 Influence of temperature on the refractive index, n, for peat soil and the results of applied corrections ..................................................59 The temperature effect on the soil refractive index, n, and the soil volumetric water content, θ TDR , determined by TDR method for three mineral soils: sand, silt and clay and the results of the applied corrections according to Eq. (43) and Eq. (46). On the right side there are values of water content, θ, determined by thermo-gravimetric method. • - TDR determined values, line – correction on n and θ...........................................................................61 145
Fig. 26. Fig. 27. Fig. 28. Fig. 29. Fig. 30. Fig. 31. Fig. 32. Fig. 33. Fig. 34. Fig. 35. Fig. 36. Fig. 37. Relaxation frequency of water molecules in relation to the distance from the solid surface and temperature according to (52) on the base of Debye model [24].........................................................63 Frequency dependence of real, ε’, and imaginary, ε”, parts of complex dielectric permittivity of salt-water mixtures for two values of electrical conductivity of the solution: EC a = 0.01 and 0.5 [Sm -1 ], at two temperatures: T=5 and 55°C of the solution.........67 Relation between the soil refractive index, n, and its water content, θ, for mineral and organic soil samples as well as their mixtures. A - experimental data, B - regression n(θ). .........................72 Comparison of model values of the EM refractive index of the soil with the use of A − model I, B − model II, C − model III and D − model IV, with the values measured with TDR device (horizontal axis)...................................................................................76 Comparison of the values of soil water content, θ TDR , calculated from the measured values of soil refractive index, n, for model I – A and model III – B with the reference values determined by the thermogravimetric method ............................................................78 The absolute error , ∆θ TDR , of the reflectometric soil water content measurement in relation of its real value, θ, and the histograms of this error referring to the model I: A and the model III: B ................79 The relative error, ∆θ rel , of the TDR soil water content results as related to the real values of its water content, θ, and the histogram of ∆θ rel for soil water content values calculated for the model I: A and the model III: B ...........................................................................80 Sensitivity of model III on the soil density, ρ, in relation to the soil, θ. ..................................................................................................81 Frequency response of dielectric mechanisms: MW, IR, V and UV are respectively microwave, infrared, visible and ultraviolet spectrum ..............................................................................................85 Basic elements of the time domain reflectometer for determination of velocity of propagation of electromagnetic waves in porous media ........................................................................86 Basic elements of the frequency domain reflectometer for determination of complex dielectric permittivity of porous media .....88 A - Open-ended coaxial probe in the form of coaxial line open to the space with material of unknown dielectric permittivity ε * , B - modeling the discontinuity of electromagnetic field by lumped capacitances C f and C 0 .........................................................................89 146
Page 2 and 3:
TDR METHOD FOR THE MEASUREMENT OF W
Page 4 and 5:
PREFACE The importance of water for
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CONTENTS 1. Status of water as an s
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12.2. New prototype version of FOM/
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that stimulate the phenomena and pr
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The solution to the problem of elec
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3. ELECTRICAL MEASUREMENTS METHODS
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v = c 1 2L = = ( θ ) n ∆t ε (2)
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The TDR probe consists of two waveg
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ε a =1 and φ=0.5 the Eq. (10) has
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The experiment description is given
Page 24 and 25:
Results obtained with the discussed
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Notice that at C s = 0, ie when dis
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water orientation polarization [s],
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Fig. 8. Frequency dispersion of the
Page 32 and 33:
The measurements were performed in
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5. EVALUATION OF DIELECTRIC MIXING
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ε α = ∑V α iε i (29) i where
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where SAND and CLAY are percents of
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Below the transition value, the soi
Page 42 and 43:
To verify the observations concerni
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6. TEMPERATURE EFFECT ON SOIL DIELE
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chamber and the freezer, only one w
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The user interface on the main comp
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soil sample volumetric water conten
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close vicinity of the analyzed obje
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process of measurement is non-destr
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dielectric permittivity change caus
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The values of the refractive index
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The relative, ∆n/∆T, and absolu
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Fig. 25. The temperature effect on
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The temperature effect of TDR soil
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The purpose of the above discussion
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( ,25 + T )( 45 + T ) 49 9 f rel =
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8. THE ACCURACY OF SOIL WATER CONTE
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gravimetric method and the soil ref
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where: a 0 ÷ a 6 are coefficients
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values of p F calculated for the re
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eason of this is the fact that wate
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9 ∆θ = 0,2 ⋅10 ⋅ ∆t = 0.00
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values of θ rel for lower values o
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9. COMPARISON OF OPEN-ENDED COAX AN
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ε" = EC ε d " + (82) 2π fε wher
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dielectric permittivity, the dielec
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The applied lumped capacitance mode
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stainless steel wires soldered to t
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ε’ Open Coax and ε b-TDR , exce
Page 96 and 97: − − The difference of the imagi
Page 98 and 99: Integrated Circuit) recently introd
Page 100 and 101: 10.2. Electromechanical microwave s
Page 102 and 103: RF1. Two PIN diodes in series in ea
Page 104 and 105: The significant aspect of the proto
Page 106 and 107: visible for lower values of soil el
Page 108 and 109: In the TDR method the signal propag
Page 110 and 111: description of functional and techn
Page 112 and 113: MASTER modules are wireless transce
Page 114 and 115: time the Real Time Clock module wak
Page 116 and 117: ase station distinguishes A SLAVE d
Page 118 and 119: sensor, format the data received fr
Page 120 and 121: 12. SOIL WATER STATUS MONITORING DE
Page 122 and 123: D-LOG/mpts is a moisture/pressure/t
Page 124 and 125: For compatibility reasons it uses t
Page 126 and 127: D-LOG/mts (Fig. 59) is a TDR (Time-
Page 128 and 129: 12.4. FP/m, FP/mts - Field Probe fo
Page 130 and 131: inside of a separate polyethylene b
Page 132 and 133: differential water capacity and the
Page 134 and 135: − maximum number of LP/p probes t
Page 136 and 137: 12.7. LP/t - Laboratory Probe for s
Page 138 and 139: From the collected data set, after
Page 140 and 141: 25. de Loor G.P.: Dielectric proper
Page 142 and 143: TDR. Symposium on Time Domain Refle
Page 144 and 145: 100. Whalley W.R.: Considerations o
Page 148 and 149: Fig. 38. The three-rod TDR probe -
Page 150 and 151: Fig. 67. A set of LP/ms and LP/p LO
Page 152: Table 17. An example of the executa
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