Characterization of Bragg grating pressure sensor using finite element analysis theory and experimental results
- Authors: Van Niekerk, Wynand F.
- Date: 2010-10-04T08:55:31Z
- Subjects: Bragg gratings , Fiber optics , Pressure transducers , Finite element method
- Type: Thesis
- Identifier: uj:6925 , http://hdl.handle.net/10210/3435
- Description: M.Ing. , Optical fibre Bragg gratings are a periodic variation of the refractive index in the core of an optical fibre andmay be formed by exposure to intense UV laser light under specific conditions. Light at a certain wavelength, called the Bragg wavelength, is reflected back when illuminating the grating with a light source. Bragg gratings can relatively easily be employed as strain and temperature sensors, but have small sensitivity for pressure. Special transducers are required to increase the sensitivity. A pressure sensor was manufactured by coating a fibre Bragg grating with a polymer. The polymer coating converts transverse pressure into longitudinal strain through the Poisson effect inside the polymer coating. This thesis investigates the sensitivity of themanufactured Bragg grating pressure sensor, by using the method of finite element analysis. An account of the experimental setup, whereby the Bragg grating is written with a frequency tripled Nd:YAG laser, is given. The process whereby the fibre is coated with the polymer is described. The sensor is characterized through experimental results and a comparison is made between theoretical and experimental results. Uses for this sensor and ways with which the sensitivity may be increased are suggested as future work.
- Full Text:
Early transition metal carbide, carbon nanoparticles (CNPs) and synthetic polymer nanocomposites for the application in hydrostatic pressure sensors
- Authors: Seroka, Ntalane Sello
- Date: 2019
- Subjects: Pressure transducers , Carbon nanotubes , Transducers , Hydrostatic pressure , Nanoscience
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/492942 , uj:45040
- Description: Abstract: Pressure sensors are very significant and are used in various areas such as automobiles, aerospace, medical industry, energy storage, corrosion protection, electrochromic devices, and electrochemical sensors. Most of the pressure sensors in the market are intended to operate either in the air, dry gases and water-based environments. Due to interferences from the environment the efficiency is hampered and life cycle of the pressure sensors is minimized. As a result, measurement errors and readings were reported due to interferences such as trapped air within a cylinder, high humidity, thus reducing sensitivity and delaying the response time. In this study we determine the pressure dependence of electrical resistance and capacitance sensitivity of a hydrostatic pressure sensor based on Metal Carbide (MC), Carbon nanoparticles (CNPs) and synthetic polymer nanocomposites deposited onto gold (Au) interdigitated electrode. We intended to utilize a cost-effective, simple, fast deposition process and fabrication of thermoplastic polymer nanocomposites for pressure sensing device and to study electrical properties of pressure sensing using Inductance (L), Capacitance (C) and Resistance (R) LCR meter. The study was carried out, whereby three fabricated pressure sensors gave appreciably good sensitivity. We report on the preparation of hydrostatic pressure sensors, based on MC, CNPs and Polyvinyl pyrrolidone (PVP). For these devices, we used CNPs with an average diameter of 30 to 40 nm. The sensor was compared with MC/CNPs/Polyyrrole (Ppy) based sensor to study polymer effect on the sensors. The sensitivities were obtained 0.158 KΩ Kpa-1, 0.077 μF Kpa-1 and 0.04 KΩ Kpa-1 (vacuum pressure) for MC/Ppy, MC/CNPs/Ppy and MC/CNPs/PVP, respectively. Thus, the MC/Ppy sensor would be suitable for resistive touchscreen technology, whereas MC/CNPs/Ppy sensor would be an ideal sensor for capacitive touchscreen applications. Hence, polymer nanocomposites have great potential application in hydrostatic pressure sensors, due to phenomenal properties than their constituent materials. , M.Sc. (NanoScience)
- Full Text:
Early transition metal carbides-multiwalled carbon nanotubes-biopolymer nanocomposites in the application of hydrostatic pressure sensor
- Authors: Makhado, Bveledzani Pertunia
- Date: 2019
- Subjects: Pressure transducers , Hydrostatic pressure , Transition metal carbides , Carbon nanotubes , Nanocomposites (Materials) , Biopolymers , Cellulose acetate
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/417534 , uj:35364
- Description: Abstract: Pressure sensors are very significant and are used in various areas such as automobiles, aerospace, medical industry, energy storage, corrosion protection, electrochromic devices, electrochemical sensor. Most of the pressure sensors in the market are intended to operate either in the air, dry gases and water-based environments. Environmental interference hampered the pressure sensors effectiveness and life cycle. As a consequence, countless measurement and reading mistakes have been reported owing to interferences such as trapped air in a cylinder and elevated humidity, thus decreasing sensitivity and delaying response time. In this study, we determine the resistance sensitivity of a hydrostatic pressure sensor based on cellulose acetate (CA), alpinumisoflavone (BI), multiwalled carbon nanotubes (MWCNTs) and metal carbides (MC) nanocomposites deposited on integrated electrode. We intended to utilize a cost-effective, simple, fast deposition process and fabrication of thermoplastic polymers nanocomposites for pressure sensing device and to study electrical properties of pressure sensing and stability using LCR meter... , M.Sc. (Nanoscience)
- Full Text: