A Non-Invasive Approach for Moisture Measurements through Patch Antennas

Different approaches and techniques are commonly available for the continuous monitoring of moisture levels and dielectric properties of materials; typically, related applications, are largely used in soil science area. Nevertheless, the state of the art is actually rather lacking in specific sensing methods that combine the low cost and the non-invasive approach of the involved instrumentation. To fill this gap, in this paper the authors study the feasibility of the adoption of the time-domain reflectometry analysis for such purposes, using a patch antenna as sensing element. This way, the extrapolation of the scattering parameters is suitably correlated to the water content levels of the materials under test. Furthermore, the adopted methodology is assessed through full-wave simulations, thus corroborating the experimental measurements.

[1]  Kosuke Noborio,et al.  Measurement of soil water content and electrical conductivity by time domain reflectometry: a review , 2001 .

[2]  S. Trabelsi,et al.  Use of microstrip patch antennas in grain and pulverized materials permittivity measurement , 2003, IEEE Antennas and Propagation Society International Symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting (Cat. No.03CH37450).

[3]  W. Bouten,et al.  Soil water content measurements at different scales: accuracy of time domain reflectometry and ground-penetrating radar , 2001 .

[4]  C. H. M. van Bavel,et al.  Soil Water Measurement with Gamma Attenuation1 , 1964 .

[5]  W. R. Gardner,et al.  DETERMINATION OF SOIL MOISTURE BY NEUTRON SCATTERING , 1952 .

[6]  L. Tarricone,et al.  Water Content Estimation in Granular Materials by Time Domain Reflectometry: a Key-note on Agro-Food Applications , 2007, 2007 IEEE Instrumentation & Measurement Technology Conference IMTC 2007.

[7]  Kevin M. O'Connor,et al.  GeoMeasurements by Pulsing TDR Cables and Probes , 1999 .

[8]  Cristiano Riminesi,et al.  Diagnostics and monitoring of frescoes using evanescent-field dielectrometry , 2006 .

[9]  A. P. Annan,et al.  Electromagnetic determination of soil water content: Measurements in coaxial transmission lines , 1980 .

[10]  Luca Catarinucci,et al.  A frequency-domain method for extending TDR performance in quality determination of fluids , 2007 .

[11]  T. Jackson,et al.  Remote sensing applications to hydrology: soil moisture , 1996 .