scholarly journals Development of a Resonant Microwave Sensor for Sediment Density Characterization

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1058 ◽  
Author(s):  
R. Mansour ◽  
S. Rioual ◽  
B. Lescop ◽  
P. Talbot ◽  
M. Abboud ◽  
...  
Keyword(s):  
Dielectric Permittivity ◽  
Water Content ◽  
Printed Circuit Board ◽  
Ionic Species ◽  
Bulk Water ◽  
Circuit Board ◽  
Complex Dielectric Permittivity ◽  
Polarization Sensitivity ◽  
Electrode Polarization ◽  
The Real

In this study, a sensor based on the development of a planar antenna immersed in sediments dedicated to water content monitoring in this type of material is proposed and experimentally validated. It is produced by a conventional Printed Circuit Board (PCB) manufacturing process on a double-sided metalized FR4 substrate. The sensitivity of the sensor is ensured by the variation of the real part of the complex dielectric permittivity of sediments with water content at around 1 GHz. As shown, in this frequency range, electrode polarization and Maxwell–Wagner polarization effects become negligible, leading to only a bulk water polarization sensitivity. The sensor operates in the reflection mode by monitoring the variation of the resonant frequency as a function of the sediment density through the S11 reflection measurements. An experimental sensitivity of 820   MHz . g − 1 . cm 3 was achieved. Despite the simplification of data interpretation at the considered frequency, the influence of ionic species such as NaCl in sediments on the real part of the relative complex dielectric permittivity is highlighted. This demonstrates the importance of considering a second parameter such as the S11 level at low frequency or the electrical conductivity to extract the density from the frequency measurements.

scholarly journals A Seven-Rod Dielectric Sensor for Determination of Soil Moisture in Well-Defined Sample Volumes

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1646 ◽  
Author(s):  
Justyna Szerement ◽  
Aleksandra Woszczyk ◽  
Agnieszka Szypłowska ◽  
Marcin Kafarski ◽  
Arkadiusz Lewandowski ◽  
...  
Keyword(s):  
Dielectric Permittivity ◽  
Water Content ◽  
Sandy Loam ◽  
Sample Volume ◽  
Time Domain Reflectometry ◽  
Complex Dielectric Permittivity ◽  
The Real ◽  
Electromagnetic Simulations ◽  
Different Diameters ◽  
Permittivity Spectrum

This paper presents a novel seven-rod sensor used for time-domain reflectometry (TDR) and frequency-domain reflectometry (FDR) measurements of soil water content in a well-defined sample volume. The probe directly measures the complex dielectric permittivity spectrum and for this purpose requires three calibration media: air, water, and ethanol. Firstly, electromagnetic simulations were used to study the influence of the diameter of a container on the sensitivity zone of the probe with respect to the measured calibration media and isopropanol as a verification liquid. Next, the probe was tested in three soils—sandy loam and two silt loams—with six water contents from air-dry to saturation. The conversion from S 11 parameters to complex dielectric permittivity from vector network analyzer (VNA) measurements was obtained using an open-ended liquid procedure. The simulation and measurement results for the real part of the isopropanol dielectric permittivity obtained from four containers with different diameters were in good agreement with literature data up to 200 MHz. The real part of the dielectric permittivity was extracted and related to the moisture of the tested soil samples. Relations between the volumetric water content and the real part of the dielectric permittivity (by FDR) and apparent dielectric permittivity (by TDR) were compared with Topp’s equation. It was concluded that the best fit to Topp’s equation was observed in the case of a sandy loam. Data calculated according to the equation proposed by Malicki, Plagge, and Roth gave results closer to Topp’s calibration. The obtained results indicated that the seven-rod probe can be used to accurately measure of the dielectric permittivity spectrum in a well-defined sample volume of about 8 cm3 in the frequency range from 20 MHz to 200 MHz.

Water Content Estimation in Soils Using Novel Planar Electromagnetic Sensor Arrays

2013 ◽  
Vol 64 (5) ◽  
Author(s):  
Mohd Amri Md Yunus ◽  
Syahrul Hisyam Mohamad ◽  
Alif Syarafi M. Nor ◽  
Muhammad Hafis Izran ◽  
Sallehuddin Ibrahim
Keyword(s):  
Water Content ◽  
Sensor Array ◽  
Printed Circuit Board ◽  
Agricultural Soils ◽  
Sensor Arrays ◽  
Circuit Board ◽  
Waveform Generator ◽  
Electromagnetic Sensors ◽  
Electromagnetic Sensor ◽  
The Relationship

Agriculture is one of the important sectors for food supplies. Therefore, a tool for monitoring the agro-environment is important in order to maintain the permanence of agricultural soils. This paper suggests an alternative method for the detection of water content in soils by developing a sensor array with a combination of planar meander and interdigital electromagnetic sensors. The study involved sensor array fabrication using the printed circuit board (PCB) method. The experimental setup consisted of a frequency waveform generator and a signal oscilloscope to collect and analyse the sensors’ output, with VEE Agilent software used to establish the interface. A set of experiments was conducted to determine the relationship between the sensors’ output and the soils’ parameters. The performance of the system was observed where the sensors were tested with the addition of various kinds of soil samples with different concentrations of water content. The sensitivity of the developed sensors was evaluated where the best sensor was selected. Based on the outcomes of the experiments, the Y sensor array placement has the highest sensitivity and can be used to measure the water content in the soils where the data accuracy is compared

scholarly journals Fringing Field Capacitive Smart Sensor Based on PCB Technology for Measuring Water Content in Paper Pulp

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Flávio Morais ◽  
Pedro Carvalhaes-Dias ◽  
Luís Duarte ◽  
Eduardo Costa ◽  
Alexandre Ferreira ◽  
...  
Keyword(s):  
Signal Processing ◽  
Water Content ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Wire Mesh ◽  
Circuit Board ◽  
Paper Machine ◽  
Smart Sensor ◽  
Paper Pulp ◽  
Paper Fabrication

We present a capacitive smart sensor based on printed circuit board (PCB) technology to measure the amount of water content in a paper pulp at the wet end of a paper machine. The developed sensor incorporates in the same PCB the signal processing circuits. It is a handheld portable device, and its output is sent to the reading equipment using a Bluetooth wireless connection, providing to the sensor’s operator ease of mobility around the wet end of a paper machine. The prototype was tested in a laboratory, using a wire mesh to emulate the end of a paper machine, and we were able to measure and easily detect when it reaches the water content in the range of 90% to 92%, as required in the paper fabrication process. Standard deviation of the capacitance measurements at various moisture levels is four orders of magnitude smaller than the mean. The smart sensor was tested in the 20°C to 40°C temperature range, in a paper pulp with a gravimetric water content of 91%. Since the variation of capacitance with temperature is practically linear, we propose a simple linear compensation equation to correct the observed sensitivity with the temperature. To keep the signal processing circuits small, low cost, simple, and robust, a novel direct interface sensor to microcontroller circuit technique was used to make the capacitive measurement, allowing for measuring small capacitance deviations without high-frequency oscillators. It was shown that it is possible to integrate the signal processing circuits in the top layer of the PCB interdigitated sensor without adding noise or degrading the performance of the capacitive sensor.

scholarly journals Open-Ended Coaxial Probe Measurements of Complex Dielectric Permittivity in Diesel-Contaminated Soil during Bioremediation

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6677
Author(s):  
Andrea Vergnano ◽  
Alberto Godio ◽  
Carla Maria Raffa ◽  
Fulvia Chiampo ◽  
Jorge A. Tobon Vasquez ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Moisture Content ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Complex Dielectric Permittivity ◽  
Imaginary Component ◽  
Real Component ◽  
The Real ◽  
Coaxial Probe

In the bioremediation field, geophysical techniques are commonly applied, at lab scale and field scale, to perform the characterization and the monitoring of contaminated soils. We propose a method for detecting the dielectric properties of contaminated soil during a process of bioremediation. An open-ended coaxial probe measured the complex dielectric permittivity (between 0.2 and 20 GHz) on a series of six soil microcosms contaminated by diesel oil (13.5% Voil/Vtot). The microcosms had different moisture content (13%, 19%, and 24% Vw/Vtot) and different salinity due to the addition of nutrients (22 and 15 g/L). The real and the imaginary component of the complex dielectric permittivity were evaluated at the initial stage of contamination and after 130 days. In almost all microcosms, the real component showed a significant decrease (up to 2 units) at all frequencies. The results revealed that the changes in the real part of the dielectric permittivity are related to the amount of degradation and loss in moisture content. The imaginary component, mainly linked to the electrical conductivity of the soil, shows a significant drop to almost 0 at low frequencies. This could be explained by a salt depletion during bioremediation. Despite a moderate accuracy reduction compared to measurements performed on liquid media, this technology can be successfully applied to granular materials such as soil. The open-ended coaxial probe is a promising instrument to check the dielectric properties of soil to characterize or monitor a bioremediation process.

scholarly journals Estimating Water Content in Water-oil Mixtures and Porous Media they Saturate: Joint Interpretation of NMR Relaxometry and Dielectric Spectroscopy

2021 ◽  
Author(s):  
Mariya Shumskayte ◽  
Andrey Mezin ◽  
Elena Chernova ◽  
Aleksandra Burukhina ◽  
Nikita Golikov ◽  
...  
Keyword(s):  
Porous Media ◽  
Dielectric Permittivity ◽  
Water Content ◽  
Dielectric Spectroscopy ◽  
Oil And Gas ◽  
Complex Dielectric Permittivity ◽  
Drill Cuttings ◽  
Nmr Relaxometry ◽  
Oil Mixtures ◽  
Joint Interpretation

The article is devoted to the topical problem of estimating water content in water-oil mixtures and porous media they saturate, according to low-field NMR relaxometry and dielectric spectroscopy. The aim of the research is to theoretically substantiate and experimentally validate the capability of joint interpretation of data from these methods to acquire information on the filtration-volumetric properties of drill cuttings, relaxation characteristics of oil-containing fluids, water/oil ratio in water-oil mixtures and saturated with them drill cuttings in order to control the composition of liquids produced from boreholes. The studies were carried out on samples of cuttings and oils taken from fields in the northern and Arctic regions of the West Siberian oil-and-gas province. Based on the experimental data obtained, we evaluated the water content in the water-oil mixtures, determined the main NMR parameters of the mixtures in terms of properties of the constituent oils, and specified the parameters and shapes of NMR and complex dielectric permittivity spectra. The NMR method was found to be effective in examining high-viscosity and medium-viscosity oils, while the dielectric spectroscopy method – in the study of light oils; their integration allows obtaining reliable data for all the samples under study. We also showed how the shapes of NMR and complex dielectric permittivity spectra depend on the rheological properties of oil belonging to the mixture.

The effect of very low water content on the complex dielectric permittivity of clays, sand-clay and sand rocks

2016 ◽  
Vol 28 (1) ◽  
pp. 014005 ◽  
Author(s):  
T A Belyaeva ◽  
P P Bobrov ◽  
E S Kroshka ◽  
A S Lapina ◽  
O V Rodionova
Keyword(s):  
Dielectric Permittivity ◽  
Water Content ◽  
Complex Dielectric Permittivity
Sign in / Sign up

Export Citation Format

Share Document