Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique

The thesis describes a short circuited waveguide technique for the determination of moisture content from reflection coefficient measurement of a waveguide loaded with Hevea rubber latex samples. The operating frequencies were from 8 GHz to 12 GHz. The theoretical part includes both the Finite Eleme...

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Main Author: KaLourazi, Parnia Tohidi
Format: Thesis
Language:English
Published: 2014
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/75956/1/FS%202014%2092%20IR.pdf
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spelling my-upm-ir.759562019-11-22T01:13:24Z Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique 2014-05 KaLourazi, Parnia Tohidi The thesis describes a short circuited waveguide technique for the determination of moisture content from reflection coefficient measurement of a waveguide loaded with Hevea rubber latex samples. The operating frequencies were from 8 GHz to 12 GHz. The theoretical part includes both the Finite Element Method and Short Circuit Line (SCL) theory to calculate the reflection coefficient of the sample placed in a waveguide. A computer program was written to implement the SCL calculation of the reflection coefficient due to the interaction between the electromagnetic waves and sample in the waveguide. Simulations using Finite Element Method was realized using the COMSOL software. The geometrical problem and the boundary conditions were first defined before performing the simulation of electromagnetic field distribution in the waveguide. The input permittivity of latex require for both SCL and FEM were obtained from measurements using Agilent Dielectric Probe Kit 85070B. Relationships between the dielectric constant, loss factor, moisture content and frequency have been established. The dielectric constant increases linearly with the measured frequency for all percentages of moisture content (% m.c). However the loss factor was inversely proportional to the operating frequencies. Samples with higher % m.c would give higher values of the dielectric constant and vice versa for the loss factor. The permittivity results were used in the calculation of the reflection coefficient. The FEM results were much closer to the measured values compared to the SCL theory for the whole frequency range between 8 GHz and 12GHz. Calibration equations to predict the % m.c from the measured reflection coefficient have been established. It was found the most accurate equation was based on the measurement of the magnitude of the reflection coefficient with accuracy within 3 % when compared to the actual mc obtained by the standard oven drying method. Circulators, Wave-guide Rubber Moisture - Measurement 2014-05 Thesis http://psasir.upm.edu.my/id/eprint/75956/ http://psasir.upm.edu.my/id/eprint/75956/1/FS%202014%2092%20IR.pdf text en public doctoral Universiti Putra Malaysia Circulators, Wave-guide Rubber Moisture - Measurement
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
topic Circulators
Wave-guide
Rubber
Moisture - Measurement
spellingShingle Circulators
Wave-guide
Rubber
Moisture - Measurement
KaLourazi, Parnia Tohidi
Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique
description The thesis describes a short circuited waveguide technique for the determination of moisture content from reflection coefficient measurement of a waveguide loaded with Hevea rubber latex samples. The operating frequencies were from 8 GHz to 12 GHz. The theoretical part includes both the Finite Element Method and Short Circuit Line (SCL) theory to calculate the reflection coefficient of the sample placed in a waveguide. A computer program was written to implement the SCL calculation of the reflection coefficient due to the interaction between the electromagnetic waves and sample in the waveguide. Simulations using Finite Element Method was realized using the COMSOL software. The geometrical problem and the boundary conditions were first defined before performing the simulation of electromagnetic field distribution in the waveguide. The input permittivity of latex require for both SCL and FEM were obtained from measurements using Agilent Dielectric Probe Kit 85070B. Relationships between the dielectric constant, loss factor, moisture content and frequency have been established. The dielectric constant increases linearly with the measured frequency for all percentages of moisture content (% m.c). However the loss factor was inversely proportional to the operating frequencies. Samples with higher % m.c would give higher values of the dielectric constant and vice versa for the loss factor. The permittivity results were used in the calculation of the reflection coefficient. The FEM results were much closer to the measured values compared to the SCL theory for the whole frequency range between 8 GHz and 12GHz. Calibration equations to predict the % m.c from the measured reflection coefficient have been established. It was found the most accurate equation was based on the measurement of the magnitude of the reflection coefficient with accuracy within 3 % when compared to the actual mc obtained by the standard oven drying method.
format Thesis
qualification_level Doctorate
author KaLourazi, Parnia Tohidi
author_facet KaLourazi, Parnia Tohidi
author_sort KaLourazi, Parnia Tohidi
title Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique
title_short Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique
title_full Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique
title_fullStr Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique
title_full_unstemmed Determination of the moisture content in hevea rubber lattex using short circuited waveguide technique
title_sort determination of the moisture content in hevea rubber lattex using short circuited waveguide technique
granting_institution Universiti Putra Malaysia
publishDate 2014
url http://psasir.upm.edu.my/id/eprint/75956/1/FS%202014%2092%20IR.pdf
_version_ 1747813100455723008