HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Moret-Fernández, D. Articles by Arrúe, J. L. Search for Related Content PubMed Articles by Moret-Fernández, D. Articles by Arrúe, J. L. GeoRef GeoRef Citation Agricola Articles by Moret-Fernández, D. Articles by Arrúe, J. L. Related Collections Water Content Soil Salinity Time Domain Reflectometry, TDR

SOIL PHYSICS

Soil Bulk Electrical Conductivity Measurement using High-Dielectric Coated Time Domain Reflectometry Probes

^a Dep. de Suelo y Agua, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, P.O. Box 13034, 50080, Zaragoza, Spain
^b Dep. de Física de la Materia Condensada, Instituto de Ciencia de Materiales de Aragón, Consejo Superior de Investigaciones Científicas, Univ. de Zaragoza, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain
^c Dep. de Ingeniería Electrónica y Comunicaciones, Instituto de Ciencia de Materiales de Aragón, Consejo Superior de Investigaciones Científicas, Univ. de Zaragoza, C/María de Luna 1, 50018, Zaragoza, Spain

^* Corresponding author (david@eead.csic.es).

Time domain reflectometry (TDR) is a technique that allows simultaneous estimates of apparent permittivity (_a) and hence volumetric water content () and bulk electrical conductivity (_a). Difficulties arise for and _a determination, however, when uncoated TDR probes (UP) are used in highly conductive media. This work shows that _a can be estimated in highly conductive media using a TDR probe coated with a high-dielectric insulator (CP). To this end, the Dalton method for _a estimations was applied to a 10-cm-long three-rod TDR probe insulated with a 0.2-mm-thick epoxy-ceramic composite coating with a relative permittivity, _r, of 32.3. This method was calibrated on different NaCl–water solutions (0–15 dS m^–1) and compared with the standard long-time TDR method for _a estimations using an UP. The method was subsequently used for determining _a in four different soils with different values of and _a (0–6 dS m^–1) and again compared with the standard TDR procedure. The low error (RMSE = 1.5) for the comparison between the _a measured with the CP and that calculated with the analytical solution for coaxial probes indicates that the CP is accurate enough for _a estimations. For _a values <4 dS m^–1, the UP allows determinations of _a and the most accurate estimations of _a using the standard TDR method (R² = 0.99). For higher _a values, however, estimations of _a were only possible using the CP, where _a was satisfactorily determined (R² = 0.99) using the Dalton method. To this end, a previous calibration between the real and the apparent bulk electrical conductivity estimated with the CP was required.

Abbreviations: CP, high-dielectric coated time domain reflectometry probe • DC, direct current • TDR, time domain reflectometry • UP, uncoated time domain reflectometry probe

This article has been cited by other articles:

				D. Moret-Fernandez, F. Lera, J. L. Arrue, and M. V. Lopez Measurement of Soil Bulk Electrical Conductivity Using Partially Coated TDR Probes Vadose Zone J., July 7, 2009; 8(3): 594 - 600. [Abstract] [Full Text] [PDF]