Abstract
The article describes a new field sensor to monitor continuously in situ moisture and salinity of a porous medium via measurements of its dielectric permittivity, conductivity and temperature. It intends to overcome difficulties and biases encountered with sensors based on the same sensitivity principle. Permittivity and conductivity are determined simultaneously by a self-balanced bridge, which measures directly the admittance of sensor electrodes in medium. All electric biases are reduced and their residuals taken into account by a physical model of the instrument, calibrated against reference fluids. Geometry electrode is optimized to obtain a well representative sample of the medium. The sensor also permits acquiring a large amount of data at high frequency (six points every hour, and even more) and to access it rapidly, even in real time, owing to autonomy capabilities and wireless communication. Ongoing developments intend to simplify and standardize present sensors. Results of field trials of prototypes in different environments are presented.
Highlights
Continuous, in situ and, potentially, real-time monitoring of water content in a porous medium, like a soil, a compost or a silo, is in large demand for academic studies as well as economic activities. Sensors with such capabilities can be used to study plant growth in agronomy or regulate irrigation in agriculture. They allow for better modeling the interactions between climate and soil moisture of a catchment area in hydrology [1], and to control ground stability under transport infrastructures, or concrete hardening process in civil engineering [2]
The measurement principle is based on the determination of medium permittivity ε r and conductivity σ
It is carried out with a high resolution and speed by a self-balanced bridge, which measures the admittance formed by the sensor electrodes in the medium
Summary
Continuous, in situ and, potentially, real-time monitoring of water content in a porous medium, like a soil, a compost or a silo, is in large demand for academic studies as well as economic activities. Sensors with such capabilities can be used to study plant growth in agronomy or regulate irrigation in agriculture. Professionals would prefer user-friendly and rugged sensors. These would be able to cope with extreme media in terms of measurement such as compost or nutrient-rich greenhouse substrates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
