The Electric Field Distribution of a Hybrid Rectangular and Circular Waveguide Resonator for Use in Granular Material Dielectric Measurements

Kittiamornkul, Navapadol; Jirasereeamornkul, Kamon; Kiattisin, Supaporn; Chamnongthai, Kosin; Higuchi, Kohji

doi:10.1541/ieejfms.135.439

Cited by 3 publications

(3 citation statements)

References 11 publications

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“…According to [ 49 ], in TE 10 mode, the cut-off frequency must be higher than 1.22 GHz and less than 2.45 GHz. Herein, the width of the sensor node,

, was 60 mm at a cut-off frequency of 1.31 GHz.…”

Section: Finite Element Modelling Of Rti Systemmentioning

confidence: 99%

A New Method of Rice Moisture Content Determination Using Voxel Weighting-Based from Radio Tomography Images

Ramli

Rahiman

Kamarudin

et al. 2021

Sensors

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This manuscript presents a new method to monitor and localize the moisture distribution in a rice silo based on tomography images. Because the rice grain is naturally hygroscopic, the stored grains’ quality depends on their level of moisture content. Higher moisture content leads to fibre degradation, making the grains too frail and possibly milled. If the moisture is too low, the grains become brittle and are susceptible to higher breakage. At present, the single-point measurement method is unreliable because the moisture build-up inside the silo might be distributed unevenly. In addition, this method mostly applies gravimetric analysis, which is destructive. Thus, we proposed a radio tomographic imaging (RTI) system to address these problems. Four simulated phantom profiles at different percentages of moisture content were reconstructed using Newton’s One-Step Error Reconstruction and Tikhonov Regularization algorithms. This simulation study utilized the relationship between the maximum voxel weighting of the reconstructed RTI image and the percentage of moisture content. The outcomes demonstrated promising results, in which the weighting voxel linearly increased with the percentage of moisture content, with a correlation coefficient higher than 0.95 was obtained. Therefore, the results support the possibility of using the RTI approach for monitoring and localizing the moisture distribution inside the rice silo.

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“…According to [ 49 ], in TE 10 mode, the cut-off frequency must be higher than 1.22 GHz and less than 2.45 GHz. Herein, the width of the sensor node,

, was 60 mm at a cut-off frequency of 1.31 GHz.…”

Section: Finite Element Modelling Of Rti Systemmentioning

confidence: 99%

A New Method of Rice Moisture Content Determination Using Voxel Weighting-Based from Radio Tomography Images

Ramli

Rahiman

Kamarudin

et al. 2021

Sensors

View full text Add to dashboard Cite

show abstract

“…Maxwell's equations are employed to derive analytical expressions for the real and imaginary parts of the complex dielectric permittivity, the resonance frequency shift, ∆f, and the change in quality factor ∆Q [25]. These expressions depend on various parameters such as the electric and magnetic fields in the empty and perturbed cavities, the permittivity and permeability of the sample, and the volumes of the cavity and the sample.…”

Section: Transfer Standard (Electromagnetic Resonant Cavity) (Lne-cet...mentioning

confidence: 99%

Calibration Techniques for Water Content Measurements in Solid Biofuels

Kjeldsen,

Østergaard,

Strauss

et al. 2024

Energies

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This paper presents methodologies and equipment for SI-traceable inline measurements of water content (a critical quality parameter) in solid biofuels. Inline measurement systems for water content are commonly used at CHP plants, providing continuous real-time data. However, the accuracy of these systems is in most cases unsatisfactory, mainly because the systems are not calibrated representatively for the relevant material, and until now, calibrations traceable to the SI system have not been available. To provide reliable and accurate inline water content data, new procedures and equipment for calibrating measurement systems were developed. Two reference methods for the determination of water content were developed; one measures the airflow and dewpoint of desorbed water in the air passing a test sample, while the other uses a P2O₅-sensor. Additionally, a transfer standard based on a cavity resonance sensor was developed for fast onsite calibration of the inline sensor at the power plant. This new instrument allows for quick and accurate measurements. The transfer standard is made metrologically traceable to the primary measurement standards. The entire system was demonstrated by calibrating an inline microwave-based (MW) sensor at the CHP plant of VERDO in Randers, Denmark. Thus, a complete metrological traceability chain was established from an industrial to a primary standard.

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“…Research on methods based on resonance [29][30][31][32][33][34] concentrates on how to distribute the electric field throughout the entire container by means of shape design. Although a beneficial design of the container shape affects the electric field distribution and the accuracy of moisture measurement, this results in a lack of flexibility of the container shape and size.…”

Section: Introductionmentioning

confidence: 99%

A Design Method for a Microwave-Based Moisture Sensing System for Granular Materials in Arbitrarily Shaped Containers

2021

Self Cite

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To estimate the moisture in an entire arbitrarily shaped workpiece, an automatic system should continuously sense moisture at all points of the workpiece. This paper proposes a design method for a microwavebased moisture sensing system for granular materials in arbitrarily shaped containers based on scanning in a moisture sensing box. The size of the moisture sensing box is first determined as the maximum size of any granular material containers based on initial user requirements. The moisture sensing system physically consists of a pair of antennas for microwave transmission and reception and a pair of distance sensors scanning throughout the maximum scanning range of the moisture sensing box to find the attenuation and workpiece thickness at all points of the workpiece, and these sensed microwave attenuations and workpiece thickness measurements are then used to calculate the moisture at all points of the workpiece. The average moisture of all points is finally taken as the estimated moisture of the whole workpiece.To evaluate the performance of the proposed system, experiments have been performed with granular materials in containers of various shapes, and the estimation results show the proposed method of continuous moisture scanning of a workpiece can improve 7.77% approximately compared with the antenna array approach.

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The Electric Field Distribution of a Hybrid Rectangular and Circular Waveguide Resonator for Use in Granular Material Dielectric Measurements

Cited by 3 publications

References 11 publications

A New Method of Rice Moisture Content Determination Using Voxel Weighting-Based from Radio Tomography Images

A New Method of Rice Moisture Content Determination Using Voxel Weighting-Based from Radio Tomography Images

Calibration Techniques for Water Content Measurements in Solid Biofuels

A Design Method for a Microwave-Based Moisture Sensing System for Granular Materials in Arbitrarily Shaped Containers

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