|
|
||||||||
Dep. of Physical Geography and Soil Science, Univ. of Amsterdam, Nieuwe Prinsengracht 130, 1018 VZ Amsterdam, the Netherlands
*Corresponding author.
ABSTRACT
Time domain reflectometry (TDR) is accepted as a valuable tool for measuring soil water content and bulk soil electrical conductivity. The accuracy of TDR measurements depends on the quality and type of probes, as well as on the length of cable used. The objective of this study was to test the effects of different triple-wire TDR probe dimensions and cable lengths on the measurements. Additional measurements were done in order to test the performance of small triple-wire probes in soils with a wide range of water contents. Measurements in air and in water showed that the position of the first reflection from the connection between cable and probe is influenced by the dielectric medium. This problem was solved by using the zero of the cable tester as a time reference, and calibrating the TDR probes before measurements. The major effect of increasing cable lengths is that the rise time of the TDR voltage pulse increases, spreading each reflection across a larger time interval, which influences the accuracy of the wave form analysis and causes a possible underestimation of the apparent dielectric permittivity in dry soils. As a result, it is not possible to use short probes with long cable lengths. Smaller spacing of the wires results in steeper reflections from the end of the probe. Small triple-wire probes are convenient in laboratory applications. Large triple-wire probes are convenient for automated field applications in which long lengths of cable are required.
Received for publication January 28, 1992.
This article has been cited by other articles:
![]() |
X. Liu, T. Ren, and R. Horton Determination of Soil Bulk Density with Thermo-Time Domain Reflectometry Sensors Soil Sci. Soc. Am. J., June 18, 2008; 72(4): 1000 - 1005. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. K. Olmanson and T. E. Ochsner A Partial Cylindrical Thermo-Time Domain Reflectometry Sensor Soil Sci. Soc. Am. J., May 1, 2008; 72(3): 571 - 577. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. K. Dettman-Kruse, N. E. Christians, and M. H. Chaplin Predicting Soil Water Content through Remote Sensing of Vegetative Characteristics in a Turfgrass System Crop Sci., March 19, 2008; 48(2): 763 - 770. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. K. Olmanson and T. E. Ochsner Comparing Ambient Temperature Effects on Heat Pulse and Time Domain Reflectometry Soil Water Content Measurements Vadose Zone J., May 26, 2006; 5(2): 751 - 756. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. B. Jones, J. M. Blonquist Jr., D. A. Robinson, V. P. Rasmussen, and D. Or Standardizing Characterization of Electromagnetic Water Content Sensors: Part 1. Methodology Vadose Zone J., November 11, 2005; 4(4): 1048 - 1058. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Blonquist Jr., S. B. Jones, and D. A. Robinson Standardizing Characterization of Electromagnetic Water Content Sensors: Part 2. Evaluation of Seven Sensing Systems Vadose Zone J., November 11, 2005; 4(4): 1059 - 1069. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Ren, Z. Ju, Y. Gong, and R. Horton Comparing Heat-Pulse and Time Domain Reflectometry Soil Water Contents from Thermo-Time Domain Reflectometry Probes Vadose Zone J., November 11, 2005; 4(4): 1080 - 1086. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. J. Kelleners, M. S. Seyfried, J. M. Blonquist Jr., J. Bilskie, and D. G. Chandler Improved Interpretation of Water Content Reflectometer Measurements in Soils Soil Sci. Soc. Am. J., September 29, 2005; 69(6): 1684 - 1690. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Robinson, S. B. Jones, J. M. Blonquist Jr., and S. P. Friedman A Physically Derived Water Content/Permittivity Calibration Model for Coarse-Textured, Layered Soils Soil Sci. Soc. Am. J., August 4, 2005; 69(5): 1372 - 1378. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. J. Kelleners, D. A. Robinson, P. J. Shouse, J. E. Ayars, and T. H. Skaggs Frequency Dependence of the Complex Permittivity and Its Impact on Dielectric Sensor Calibration in Soils Soil Sci. Soc. Am. J., January 1, 2005; 69(1): 67 - 76. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. J. Heimovaara, J. A. Huisman, J. A. Vrugt, and W. Bouten Obtaining the Spatial Distribution of Water Content along a TDR Probe Using the SCEM-UA Bayesian Inverse Modeling Scheme Vadose Zone J., November 1, 2004; 3(4): 1128 - 1145. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Persson, D. Bendz, and P. Flyhammar Time-Domain Reflectometry Probe for Water Content and Electrical Conductivity Measurements in Saline Porous Media Vadose Zone J., November 1, 2004; 3(4): 1146 - 1151. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Lebron, D. A. Robinson, S. Goldberg, and S. M. Lesch The Dielectric Permittivity of Calcite and Arid Zone Soils with Carbonate Minerals Soil Sci. Soc. Am. J., September 1, 2004; 68(5): 1549 - 1559. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. B. Jones and D. Or Frequency Domain Analysis for Extending Time Domain Reflectometry Water Content Measurement in Highly Saline Soils Soil Sci. Soc. Am. J., September 1, 2004; 68(5): 1568 - 1577. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Robinson Measurement of the Solid Dielectric Permittivity of Clay Minerals and Granular Samples Using a Time Domain Reflectometry Immersion Method Vadose Zone J., May 1, 2004; 3(2): 705 - 713. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Robinson, D. A. Robinson, S. B. Jones, J. M. Wraith, D. Or, and S. P. Friedman A Review of Advances in Dielectric and Electrical Conductivity Measurement in Soils Using Time Domain Reflectometry Vadose Zone J., November 1, 2003; 2(4): 444 - 475. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. Huisman, J. J. J. C. Snepvangers, W. Bouten, and G. B. M. Heuvelink Monitoring Temporal Development of Spatial Soil Water Content Variation: Comparison of Ground Penetrating Radar and Time Domain Reflectometry Vadose Zone J., November 1, 2003; 2(4): 519 - 529. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Ren, T. E. Ochsner, and R. Horton Development of Thermo-Time Domain Reflectometry for Vadose Zone Measurements Vadose Zone J., November 1, 2003; 2(4): 544 - 551. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. C. Harlow, R. C. Harlow, E. J. Burke, T. P. A. Ferre, J. C. Bennett, and W. J. Shuttleworth Measuring Spectral Dielectric Properties Using Gated Time Domain Transmission Measurements Vadose Zone J., August 1, 2003; 2(3): 424 - 432. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. G. Schaap, D. A. Robinson, S. P. Friedman, and A. Lazar Measurement and Modeling of the TDR Signal Propagation through Layered Dielectric Media Soil Sci. Soc. Am. J., July 1, 2003; 67(4): 1113 - 1121. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Persson and S. Haridy Estimating Water Content from Electrical Conductivity Measurements with Short Time-Domain Reflectometry Probes Soil Sci. Soc. Am. J., March 1, 2003; 67(2): 478 - 482. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Robinson, M. Schaap, S. B. Jones, S. P. Friedman, and C. M. K. Gardner Considerations for Improving the Accuracy of Permittivity Measurement using Time Domain Reflectometry: Air-Water Calibration, Effects of Cable Length Soil Sci. Soc. Am. J., January 1, 2003; 67(1): 62 - 70. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Persson and J. M. Wraith Shaft-Mounted Time Domain Reflectometry Probe for Water Content and Electrical Conductivity Measurements Vadose Zone J., November 1, 2002; 1(2): 316 - 319. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. E. Ochsner, R. Horton, and T. Ren Simultaneous Water Content, Air-Filled Porosity, and Bulk Density Measurements with Thermo-Time Domain Reflectometry Soil Sci. Soc. Am. J., November 1, 2001; 65(6): 1618 - 1622. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.D. Logsdon Effect of Cable Length on Time Domain Reflectometry Calibration for High Surface Area Soils Soil Sci. Soc. Am. J., January 1, 2000; 64(1): 54 - 61. [Abstract] [Full Text] |
||||
![]() |
J.A. Huisman and W. Bouten Comparison of calibration and direct measurement of cable and probe properties in time domain reflectometry Soil Sci. Soc. Am. J., November 1, 1999; 63(6): 1615 - 1617. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. B. Bryan, R. M. Hawke, and D. L. Rockwell Automated Microstandpipe System for Soil Erosion Research Soil Sci. Soc. Am. J., July 1, 1999; 63(4): 977 - 987. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Vadose Zone Journal | Journal of Plant Registrations | ||||
| Journal of Natural Resources and Life Sciences Education |
Journal of Environmental Quality |
||||