Theoretical and experimental study of a time-domain-reflectometry (TDR) probe used for water content measurement of clayrock through their electromagnetic properties

T. Bore; D. Placko; F. Taillade; S. Lesoille-Delepine; G. Six; P. Sabouroux

doi:10.1117/12.2009832

19 April 2013 Theoretical and experimental study of a time-domain-reflectometry (TDR) probe used for water content measurement of clayrock through their electromagnetic properties

T. Bore, D. Placko, F. Taillade, S. Lesoille-Delepine, G. Six, P. Sabouroux

Author Affiliations +

Proceedings Volume 8692, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2013; 86921U (2013) https://doi.org/10.1117/12.2009832
Event: SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2013, San Diego, California, United States

Abstract

The use of electromagnetic sensors such as Time Domain Reflectometry (TDR) probes has gained increasing importance for water content measurements since several years, for long term monitoring of structures, among which radioactive waste repositories. TDR probes are basically sensitive to electromagnetic properties of the host material, clayrock in our case Prior to perform in-situ experiments with TDR probes, it is mandatory to have an accurate knowledge of the electromagnetic properties of clayrock as a function of their water content. We developed a new laboratory dielectric measurement device, consisting of a coaxial transmission line, enabling characterization of intact clayrock permittivity over the 50 MHz - 1 GHz frequency range. The study has shown a large variation of complex permittivity with (i) water content, the parameter of interest and (ii) frequency. The frequency dependence is induced by different relaxation processes. In a second step, these data are introduced in an original semi analytical model (Distributed Points Sources Method) in order to obtain a reliable modeling of the TDR probe. Taking into account some experimental aspects of the TDR probe, we propose to introduce a in this paper the effect of an air gap between the TDR antennas and the surrounding media. The effect of this influent parameter is evaluated owing to our DPSM modeling, and some solutions are proposed to overcome the problem.

Citation Download Citation

T. Bore, D. Placko, F. Taillade, S. Lesoille-Delepine, G. Six, and P. Sabouroux "Theoretical and experimental study of a time-domain-reflectometry (TDR) probe used for water content measurement of clayrock through their electromagnetic properties", Proc. SPIE 8692, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2013, 86921U (19 April 2013); https://doi.org/10.1117/12.2009832

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available