# data[].attributes.headline
Case Study: Measuring Forces in a Beating Heart

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Case Study: Measuring Forces in a Beating Heart

# data[].attributes.body
Mohd. Azfar Danial bin Azharan 50147
Awang Mohamed Hazim bin Norajiki 59985

# data[].attributes.headline
Case Study: Capacitive Pressure Sensors for Medical Applications

# data[].attributes.subject
Case Study: Capacitive Pressure Sensors for Medical Applications

# data[].attributes.body
Mohd Nurul Iman bin Fouzi (58761)
Akmal Khusairi Bin Karim (55390)

Capacitive pressure sensors and switch fabrication using strained compensated silicon-germanium-boron (SiGeB) have been developed by a team of researchers led by Stavros Chatzandroulis at the Institute of Microelectronics, NCSR 'Demokritos', Greece. Researchers from the Department of Applied Sciences, National Technical University of Athens have also collaborated with Chatzandroulis in their quest to produce capacitive pressure sensors that exhibit good yields and high performance.

The capacitive pressure sensors and pressure switches were fabricated using a 2.4 micrometer thick strain compensated heavily boron doped SiGeB diaphragm. To seal the pressure sensor cavity and construct the device, the process relied heavily on the silicon fusion bonding between the two silicon wafers. Both rectangular and circular type pressure sensors and pressure switches were successfully fabricated using this process.

Talking to Sensor Technology Chatzandroulis emphasized, "Our capacitive sensors are particularly suitable for the medical field. In this field, miniaturization of both sensor and packaging size as well as minimization of the power requirements of the sensor are the major drivers. For example, blood pressure measuring catheters need to penetrate into small blood vessels putting stringent requirements on sensor size, which should be half the size of the vessel to be accessed. In small vessels, catheters usually have a diameter of [two millimeters]. Our capacitive sensors are well within these size requirements."

Drivers for the acceptance of this technology are applications such as abdominal aortas aneurysm and congestive heart failure. These are the major cardiovascular diseases affecting people, and an implantable pressure monitoring system, which would tailor treatment medication by measuring blood pressure, is a very attractive prospective. Implantable applications will require a miniature battery-less telemetric sensor, which will be able to communicate with an external handheld unit. In such applications, power consumption becomes an additional issue and these capacitive devices offer a clear advantage over piezoresistive ones. Other potential applications include intraocular pressure monitoring for the treatment of glaucoma (a serious disease characterized by an increased pressure in the eye that may result in blindness), intracranial pressure monitoring for the treatment of patients with head trauma, and monitoring of neurological patients.

The capacitive sensors developed in this research exhibit good yields and performance. They can be fabricated in extremely small sizes (currently 0.8 mm × 1.1 mm including a reference capacitance) while further miniaturization is easily achievable and is on the cards. The results of this capacitive type sensor operating in the medical pressure regime (0 to 300 mmHg) with a sensitivity to pressure of 1.5 fF/mmHg (10⁻¹⁵ or femto-farad/million of Hg) or 305 ppm/mmHg, and of a pressure switch operating in the 3 bar to 8 bar pressure range prove their versatility. They are thus suitable for a number of industrial and automotive applications.

Commercial applications include the potential applications mentioned above. A special interest exists in using the sensors in implantable pressure sensor monitors where their miniature size and inherent low power consumption give them additional advantages. Apart from the medical field, potential commercial applications of the sensors include remote wireless sensors where power minimization is of paramount importance. One such application is a tire pressure monitoring system for the monitoring of pressure in vehicle tires. Such systems will become mandatory in US light vehicles, with the phase-in of the TREAD (Transport Recall Enhancement, Accountability and Documentation) act during October 2005 to September 1, 2007.(Vehicles produced by final-stage manufacturers and alterers are to be equipped with a compliant TPMS (including a malfunction indicator) by September 1, 2008.)

Reference
Capacitive Pressure Sensors for Medical Applications | Sensors Magazine. (2019). Retrieved from https://www.sensorsmag.com/components/capacitive-pressure-sensors-for-medical-applications

# data[].attributes.headline
Eugene Tang (55900) Kelvin Lau Kuan Fei (56284)

# data[].attributes.subject
Eugene Tang (55900) Kelvin Lau Kuan Fei (56284)

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Case study on solving the burden of Bourdon Tubes

# data[].attributes.body
Norsyafrizal Bin Amin (58922)
Shahanim Syahirah Binti Khusrin Shah (57805)

Vacuum systems are
at the forefront of research activities in innovation and high-tech products. Therefore, with the increasing use of these systems, especially in the area of the up and middle vacuum in the new
sciences and industries, it is necessary to develop appropriate measurement methods and to use gauges that are reliable in accuracy and the validity.
In other words, they are needed to be calibrated because the calibration of the sensors is important due to the repeatability of the process, achieving optimum quality, tracking production problems, preventing damage to the vacuum generator and user safety.
Vacuum gauges of McLeod, thermocouple, Pirani and capacitive are among the most widely used equipment in vacuum systems. Due to the wide range of pressure in these systems, a combination
of two vacuum gauges of Pirani
and capacitive is used in the chamber to measure the pressure in the lower and medium range (range 1013 to 10-3 mbar) and the high vacuum range (range 10-3 to 10-7 mbar), respectively.

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Case Study - Load Detection in Washing Machines VIP Sensor

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Case Study - Load Detection in Washing Machines VIP Sensor

# data[].attributes.body
Christopher Joyle Indor (55745)
Petrus Gabriel Dana (59118)

# data[].attributes.body
Aizatul Farzana binti Salim (58427)
Nurashidah binti Azman (59034)

The demand for the bourdon tube pressure gauge is getting higher. Ultimately wear on a gauge movement or plastic deformation of the Bourdon tube
can lead to failure of the measuring element.

Here are some ways on how to improve the efficiency of the bourdon tube pressure gauge.

Problem
1. The combined effect of pressure loading and elastic deformation due to mechanical vibration produce areas of high
stress within a Bourdon tube. These areas of high stress initially cause the calibration of the instrument to shift and
can ultimately lead to the failure of the tube itself.

2. Usually the simple and cost effective way of closing the end of a
Bourdon tube is to pinch the end and seal it with a weld. FEM stress analysis of this technique shows that this creates an area of high stress at the end of the tube. Under pressure cycling tests this method of closing the tube lead
to a failure after about 300,000 cycles.

Solution
1. Using FEM (finite element method) calculations, the stresses of a Bourdon tube when under pressure and when
subjected to mechanical vibration were determined. It is therefore clear that the area of maximum stress occurs where the effects of the pressure and vibration stresses combine in the area of 30° to 60° along
the tube from the connection.
Therefore, there are 3 ways to reduce the stress:

a) By cold working the Bourdon tube during the manufacturing process it is possible to increase the yield point of the tube from 250 N/mm2 to 400-600 N/mm2. This stronger tube gives an improved performance and service life.

b) By using the WIKA Bourdon tube design. The area of maximum stress on the tube between 30° and
60° was found to be at the narrow edge of the tube. The development of a WIKA tube design with a more rounded profile was found to reduce these stresses at the
narrow edge.

c) Damping the tube movement by liquid filling the case. Liquid filling the pressure gauge case reduces the effects of mechanical vibration on the Bourdon tube by reducing the amplitude of its vibration.

2. By keeping the tube profile unaltered at the end and closing the tube with a weld cap of the same material, the
stress was significantly reduced. The same pressure cycling tests were repeated using
this technique and after 3 million cycles the tube had not failed.

# data[].attributes.attachment_link.title
Safety and Longterm Accuracy of Bourdon Tube Pressure Gauges

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Nur Syazwanie binti Ali
Siti Farha binti Azhar

In the current work,  a compact and cost effective Pirani gauge is presented based on Silicon-On-Nothing (SON) technology. The proposed design uses an innovative approach of etching the sensing element directly in a crystalline silicon membrane.
Such configuration allows pressure dependent heat losses to act on the substrate not only through the bottom cavity and trenches but also via the top cavity on the lid, which is formed by means of a sacrificial layer. By ensuring process compatibility with other SON-based MEMS, the proposed device can be used as a tool for cavity pressure monitoring and product support over the whole life cycle of MEMS: ranging from fabrication to calibration during field tests.
Performance of the device is investigated based on numerical simulations and measurements. Furthermore, work includes a discussion of the fabrication process along with an additional cavity pressure characterisation.

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Case study: Piezoelectric pressure sensor for Generate Energy on exas Roads

# data[].attributes.subject
Case study: Piezoelectric pressure sensor for Generate Energy on exas Roads

# data[].attributes.body
Suman Das (59425)
Lim Fook Syn (56434)

# data[].attributes.headline
Case Study: An Inductive Transducer based Pressure Sensor for Biomedical Applications

# data[].attributes.subject
Case Study: An Inductive Transducer based Pressure Sensor for Biomedical Applications

# data[].attributes.body
Dina Dzuremilia Binti Asan (58556)
Nur Afiqah Binti Mohamad Malek (58929)

# data[].attributes.attachment_link.title
[Case Study] An Inductive Transducer based Pressure Sensor for Biomedical Applications

# data[].attributes.headline
Case study: Advanced Tactile Sensor Drive the Next Generation of Blood Pressure Devices

# data[].attributes.subject
Case study: Advanced Tactile Sensor Drive the Next Generation of Blood Pressure Devices

# data[].attributes.body
Royce Anak Thomspon (59146)
Esther Suling Edmond (58583)

Challenges:

High blood pressure which is also known as Hypertension is the number one risk factor for premature death worldwide, affecting 70 million American adults. The best way to monitor and mitigate the risks of hypertension is by performing day-to-day blood pressure measurement. While there are many methods being used for performing blood pressure measurement, all but the most invasive, intraarterial techniques suffer from deficiencies that can lead to inaccurate or inconsistent results. These limitations are basically derived from several cases which are the quality of the signal, errors in human interpretation, and calculation methods that rely on indirect or algorithmic interpretations. For non-invasive techniques, intermittent measurement of blood pressure, the gold standard is the blood pressure cuff or sphygmomanometer. By using this device, a trained healthcare provider listens with a stethoscope for the Korotkoff (taping) sounds as the cuff is gradually deflated to determine the systolic and diastolic pressure. Although widely being accepted and used, some studies has proven that manual blood pressure measurement can include errors as large as 10mmHg for systolic and diastolic pressures. In particular, the procedure is sensitive to clinician’s hearing acuity and overall diligence while performing the procedure.

Solutions:

Capacitive tactile sensors can be used to replace the non-invasive techniques as blood pressure can be measure using sophisticated arrays that map the pressure above the artery. This can range from a few discrete measurements to a large, dense array of hundreds of elements. These sensors are in direct proximity to the artery which deliver a detailed pulse waveform that is then used to determine the blood pressure and pulse information. This includes the other parameters such as arterial hardening. This device is well suited for this task due to its ability to handle the extremely low pressures that need to be measured. Other than that, it is designed to be integrated into a variety of soft, flexible materials to conform to the contours of the human body and other curved surfaces. Furthermore, these sensors are high in sensitivity. The small form factor, the conformable materials enabling seamless integration into wearable devices, and the tactile array configuration. These sensors measured pressure directly and not trying to infer it by optical or electrical properties. Another promising application for this sensor is arterial line placement. The device uses tactile sensor arrays in a conformable material that is worn over the clinician’s index and middle fingers. The tactile sensor identifies the location of the pulse and indicates the location using LEDs and a needle guide to facilitate needle insertion. This protects the clinician’s fingers against needle-stick injuries.

References
Medical Design Briefs (2017, April 1). Advanced tactile sensors drive the next generation of blood pressure devices. Retrieved from https://www.medicaldesignbriefs.com/component/content/article/mdb/features/articles/26701

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Piezoelectric Roads: Energy Harvesting Method Using Piezoelectric Technology

# data[].attributes.subject
Piezoelectric Roads: Energy Harvesting Method Using Piezoelectric Technology

# data[].attributes.body
Vanessa Shaira anak Ngali (52939)
Felicity Deliastasia anak Robin (58612)

As the demand of fossil fuel is enormously increasing over time, the future of generating power using non-renewable energy will come to a halt. In 2004, the global energy consumption level of non-renewable energy has risen to 80%, and will remain increasing in the next 20-30 years due to population growth as a main factor. This level results in a drastic amount of CO emissions and greenhouse gasses being pumped into the air raising concerns on rising sea levels, increasing average temperature, and extreme weathering conditions.

The term Energy Harvesting or Renewable Energy, such as solar panels or wind turbine, is a method of producing electrical energy by utilizing the energy surrounding the environment from the sun and wind, for example.

However, energy formed from various vibration machines, objects in motion, or any other source of mechanical energy is not being captured. Therefore, this source of energy is dispersed and thus wasted. As an effective method to utilize this loss, piezoelectric material is used to absorb the wasted mechanical energy and convert it to electrical energy.

In 2009, the Ayalon, Coastal, and Trans-Israel Highway were embedded with piezoelectric devices 5 cm below road level to test its efficiency in terms of electrical energy supplied by the moving vehicles. This test was proposed by an Israeli company named Innowattech that specializes in improving green methods to harness waste energy using piezoelectricity. The project was set to test a one km stretch of a single and four lane road integrated with piezoelectricity. The results meet the required amount of energy in which 200 KWh for a single lane and one MWh on four lanes were generated at that time.

Having met the power metrics will make such invention a starting point to self-sustaining environment by being dependent on vehicle elements to curb down input energy and cost. This will be a revolution in the production of energy by meeting innovations and technologies to shape future energy. However, further concentration is required to quantify and result in a greater power outcome to become a reliable source of electricity.

# data[].attributes.headline
Hermetic Capacitive Pressure Sensors for Biomedical Applications

# data[].attributes.subject
Hermetic Capacitive Pressure Sensors for Biomedical Applications

# data[].attributes.body
Probal Roy (59422)
Tamjidur Rahman (60068

# data[].attributes.headline
A Detailed Examination of the Principles of Ion Gauge Calibration

# data[].attributes.subject
A Detailed Examination of the Principles of Ion Gauge Calibration

# data[].attributes.body
Choo Yun Jian 55732
Ng Ji Wei 56931

In the ideal ionization gauge the gas is bombarded by an electron current and produce at a positive ion current. However, in the practical ionization gauge, not all the electron emission current is effective in producing ionization and not all of the ions produced are collected, in other words it is not perfect. Therefore, specific equations are used to calculate the effective electron current and the true ion current. From this case study, an ionization gauge actually only indicates the atom concentration but not pressure, the pressure is only calibrated when a McLeod gauge is used as the reference standard. In this study, when the pressure increases the effective ionization efficiency could increase as well as it is energetically possible.

From this case study, ion gauges must generally be operated in the 1 to 10 microampere range of electron current and that the systematic variation in K with pressure in the best calibration range, namely, 10 - 4 up to 10- 3 mm must be understood in order that the most suitable value of Ko may be used in the very low pressure range.

# data[].attributes.headline
A Simple Graphical Method Of Pressure Determination In A McLeod Gauge

# data[].attributes.subject
A Simple Graphical Method Of Pressure Determination In A McLeod Gauge

# data[].attributes.body
Mohd Harith Bin Ramzi (58751)
Maziz Syafiq Bin Mujib (58704)

# data[].attributes.attachment_link.title
A simple graphical method of pressure determination in a McLeod gauge

# data[].attributes.body
tion
of two vacuum gauges of Pirani
and capacitive is used in the chamber to measure the pressure in the lower and medium range (range 1013 to 10-3 mbar) and the high vacuum range (range 10-3 to 10-7 mbar), respectively.

# data[].attributes.headline
Case study of Mcleod Gauge for use in evacuating refrigerating system

# data[].attributes.subject
Case study of Mcleod Gauge for use in evacuating refrigerating system

# data[].attributes.body
Muhammad Adhkhan Khawari Bin Jusoh (58782)
Fakhrul Anwar bin Mohd Radiansah (55926)

Eight different instruments for indicating the absolute pressure of gases in a part, ranging from 0.02 to 20 mmHg were investigated for their suitability for field use in evacuating refrigerating systems during service operations. The test specimens included mercury McLeod gages, thermocouple gages, one electric resistance gage, and one absolute aneroid gage. The aneroid gage and one of the McLeod gages were calibrated against an NBS working standard and used thereafter as reference gages for comparison with the other test specimens. Dry nitrogen, dry air, laboratory air, saturated air, water vapor, and the refrigerant gases of R11, R12 and R22 were used as test gases. It was found that the aneroid gage was probably best suited for field use in terms of accuracy, applicability, ruggedness, simplicity, and ease of use. The McLeod gages, the electric resistance gage and some of the thermocouple gages however, were found to provide acceptable accuracy for limited ranges of pressure and for a narrower choice of gases in most cases.

One principal method of removing water, air, or undesirable gases or vapours from refrigerating systems is the evacuation to low absolute pressures. Recommended evacuation pressures for this purpose are usually 100 microns Hg absolute or lower. However, on the production lines for commercial refrigerating units, evacuation pressures may be lower than 10 microns Hg absolute and the systems for producing and measuring these pressures are frequently quite sophisticated. For field evacuation of refrigerating systems to low absolute pressures, moderately-priced, portable gages capable of accurately measuring absolute pressures in the range from 100 microns Hg to 1000 microns Hg or greater are needed to determine whether the prescribed low pressures have been achieved. The McLeod gages would have usefulness where water vapour or saturated gases were not involved and where the lever movements required could be safely and effectively. McLeod gages cannot be used to reliably measure the pressure of gases if the pressure in the compression tube of the gage at the time of measurement approaches the condensing pressure of the gas. For this reason, the Kinney McLeod gage was not used as a reference gage in tests with saturated air or water vapour. The pressure in the measuring tube of a mercury McLeod gage is equal to the system pressure plus the mercury head required to compress the sample.

# data[].attributes.attachment_link.title
A Case Study of Vacuum Gages for Use in Evacuating Refrigerating System

# data[].attributes.headline
Case study: Checking presence of metal wave washer during switch assembly

# data[].attributes.subject
Case study: Checking presence of metal wave washer during switch assembly

# data[].attributes.body
Lucas Chai Kim Hong (56518)
Chua Hui Leng (55748)

# data[].attributes.body
Cheryl Rinai Raja (58527)
Zul Farra Ain binti Misman (59259)

CASE STUDY ON BOURDON TUBE

Objects of the invention include an improved Bourdon tube pressure gauge which is utilized in conjunction with optical strain sensors for providing a pressure gauge which is accurate and reliable at high temperature and pressure conditions.
A further object of the present invention is to provide such a pressure gauge, which is temperature compensated over the full range of operating temperatures of the pressure gauge.

According to the present invention:

1. A Bourdon tube pressure gauge is connected to at least one optical strain sensor mounted to be strained by movement of the Bourdon tube such that when the Bourdon tube is exposed to the pressure of a system being monitored, movement of the tube in response to system pressure causes a strain in the optical sensor, the optical sensor being responsive to the strain and to an input optical signal for providing a strain optical signal which is related to the pressure.

2. The optical sensor includes an optical fiber having an intrinsic Bragg grating sensor formed in the optical fiber, the optical fiber being attached to a reference point and to the Bourdon tube such that changes in the position of the tube changes the strain on the optical fiber resulting in a wavelength shift of light reflected by the Bragg grating, the magnitude of the wavelength shift being indicative of a change in pressure.

3. The Bragg grating sensor is mounted between the Bourdon tube and the reference point under an initial strain condition, and wherein the initial strain changes in response to changes in the position of the Bourdon tube in response to changes in system pressure.

4. A reference or temperature compensation optical sensor is isolated from the mechanical strain associated with the pressure of the system and is responsive to the temperature of the system for causing a temperature induced strain, the reference optical sensor being responsive to the temperature induced strain and the input optical signal for providing a temperature optical signal which is related to the temperature of the system, the temperature optical signal being provided for temperature compensation of the strain optical signal. The reference optical sensor may also be a Bragg grating sensor.

5. Light reflected by the Bragg grating sensors may be remotely sensed to thereby provide a remote measurement of locally sensed pressure and temperature.

6. A plurality of Bragg gratings may be arranged with respect to the Bourdon tube such that in response to changes in the position of the Bourdon tube caused by a change in pressure of the system, the strain on at least one Bragg grating is increased while the strain on at least one additional Bragg grating sensor is reduced, each Bragg grating sensor being responsive to an input optical signal and the strain for providing an output strain signal indicative of the system pressure.

7. The Bragg gratings may be provided in several different arrangements, including being attached directly to the surface of the Bourdon tube, or connected between the end of the Bourdon tube and a referenced location. The Bourdon tube may be a simple, generally circular or arc shaped Bourdon tube, or alternatively a helical shaped Bourdon tube or other suitable tube configuration may be utilized.

8. A plurality of pressure gauges may be coupled to a single optical fiber, and the separate signals from each sensor may be provided via wavelength division multiplexing techniques, time division multiplexing techniques or a combination thereof.

The present invention provides a significant improvement over the prior art. A simple pressure gauge is provided which is particularly suited for use in high temperature, high pressure and hostile environments. Additionally, the gauge of the present invention is easily temperature compensated for providing a reliable and accurate pressure signal. There is no requirement to provide electronic processing equipment directly at the gauge location as the light signals reflected by the optical strain sensors in the gauge can be transmitted via an optical fiber to a remote location for processing. Therefore, a very highly reliable and accurate pressure gauge is provided. The optical fiber and sensors utilized with the invention are functional over a wide temperature range, and therefore, the gauges of the invention may be used in both hazardous and high temperature locations.

# data[].attributes.headline
CHIN JING KEY (55689) & MAGRET IPAH ANAK JUNI (5

# data[].attributes.subject
CHIN JING KEY (55689) & MAGRET IPAH ANAK JUNI (5

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Case Study: From Pit Lane to Start Line in No Time

# data[].attributes.subject
Case Study: From Pit Lane to Start Line in No Time

# data[].attributes.body
Mohd Laji Bin Sumarno (58754)
Muhammad Ilman Hanif Bin Mohd Sarif (58822)

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The Micro Pirani Gauge with Low Noise CDS-CTIA forIn-Situ Vacuum Monitoring

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The Micro Pirani Gauge with Low Noise CDS-CTIA forIn-Situ Vacuum Monitoring

# data[].attributes.body
Alexander Kuleh Paul 55401
Mahendra Suhartono Suwandhi

A resistive micro Pirani gauge using

amorphous silicon (a-Si) thin membrane is proposed.

The proposed Pirani gauge can be easily integrated

with the other process-compatible membrane-type

sensors, and can be applicable for in-situ vacuum

monitoring inside the vacuum package without an

additional process. The vacuum level is measured by

the resistance changes of the membrane using the low

noise correlated double sampling (CDS) capacitive

trans-impedance amplifier (CTIA). The measured

vacuum range of the Pirani gauge is 0.1 to 10 Torr.

The sensitivity and non-linearity are measured to be

78 mV / Torr and 0.5% in the pressure range of 0.1 to

10 Torr. The output noise level is measured to be 268

μVrms in 0.5 Hz to 50 Hz, which is 41.2% smaller than

conventional CTIA.

The proposed micro Pirani gauge can be easily

integrated with the membrane-type sensor using a-Si, i.e.

microbolometer, and can be used for in-situ vacuum

monitoring inside the vacuum package. This will offer

low cost integration for in-situ monitoring of the vacuum

level inside the package.

Traditionally, vacuum sensors are measured small

resistance changes by Wheatstone bridge [10] as shown

in Fig. 5(a).

The Fig. 5(a) shows the

conventional readout circuit by the instrument amplifier.

The output voltage of this circuit, VOUT can be expressed

as (6) [refer pdf], where G is the gain of the instrumentation

amplifier.

Many researches have been reported to reduce the

noise, chip size and power consumption [9, 10]. Among

them, the capacitive trans-impedance amplifier (CTIA) is

the one of the most popular approaches due to its low

power consumption and small size.

A micro Pirani gauge sensor using amorphous silicon

(a-Si) thin membrane with low noise CDS CTIA resistive

front-end is presented. The Pirani gauge is fabricated

using post-CMOS process, and its fabrication process is

fully CMOS compatible. The measured linear vacuum

range of the Pirani gauge is 0.1 to 10 Torr. The sensitivity

and non-linearity are measured to be 78 mV / Torr and

0.5% in the pressure range of 0.1 to 10 Torr. The output

noise level of the proposed CDS-CTIA system is

measured to be 268 μVrms in 0.5 Hz to 50 Hz, which is

41.2% smaller than conventional CTIA without CDS.

The presented Pirani gauge can be easily integrated with

the general membrane-type vacuum packaged sensor, and

can be used for in-situ vacuum monitoring inside the

vacuum package.

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MUHAMMAD YAZID BIN MOHAMAD FUAD (58852)

MOHD FADZIL NIZA BIN ABANG (59327)

# data[].attributes.headline
Case Study: Correction of Temperature Error of Pressure Piezoelectric  Sensors for Space Technology Products

# data[].attributes.subject
Case Study: Correction of Temperature Error of Pressure Piezoelectric  Sensors for Space Technology Products

# data[].attributes.body
UTHMAN ARIFF BIN ZAHARUDDIN (59235)
MUHAMMAD FITRI ADIB BIN NOORAZAMI (58811)

This case study presents the questions of correction of temperature error of piezoelectric pressure sensors in conditions of transient temperature and thermal shock. It is noted that when the piezoelectric pressure sensor is operating in thermal shock conditions, it is important to measure the main parameter by means of the piezoelectric sensor: the pressure and piezoelectric element temperature at a single point of space and at the same time to eliminate the influence of the temperature gradient. That makes difficult to use additional sensors to measure the temperature of the actuating medium. It is proposed to use the impedance parameters of working and vibrocompensation piezoelectric elements as information source about the temperature of piezoelectric elements. The scheme of secondary transmitter of output signals of working and vibrocompensation piezoelectric elements is presented; its description and algorithm for obtaining the correction signals are described. The results showed that the change of the conversion efficiency of the pressure piezoelectric sensor of the piezoelectric elements form the PZT-83G piezoelectric material in the range of - 180 to + 200 °C is approximately 35%. Moreover, time dependence of output signals from the working and vibrocompensation piezoelectric elements of the pressure piezoelectric sensor when exposed by thermal shock of liquid nitrogen is presented. It is shown that using the proposed correction method of measurement errors from the transient temperature of the actuating medium can reduce measurement error of dynamic pressure from the thermal shock. Sensors are the basis of automatic control systems for space applications. Sensors perceive not only the data on the measured value, but also the impact of wide range of influencing factors that emerge during the operation in the so-called harsh environments. The sensor equipment, used for this purpose, is exposed to an extremely concentrated and complex effect of destabilizing factors, such as change of pressure, high levels of vibration and shock, acoustic noise, transient temperatures of the actuating medium, thermal shocks. The influence of the quick-changing and acoustic pressures of transient cryogenic temperatures, which affect the sensing elements of the primary transducers of piezoelectric sensors, on the metrological characteristics of the sensors is one of the most important factors that determine whether the use of these sensors is possible in each specific case.

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Case study: How traffic lights sensors work?

# data[].attributes.subject
Case study: How traffic lights sensors work?

# data[].attributes.body
Gan Yi Jiunn (56034)
Oliver Yii Chii Sing (57595)

# data[].attributes.attachment_link.title
Case study for inductive pressure transducer

# data[].attributes.headline
case study of the K McLeod gauge methodsfor the calibration of high vacuum gauges 

# data[].attributes.subject
case study of the K McLeod gauge methodsfor the calibration of high vacuum gauges 

# data[].attributes.body
Name:AL Amin
Matric no 59398

# data[].attributes.headline
Single and bulk compression of pharmaceutical excipients: Evaluation of mechanical properties 

# data[].attributes.subject
Single and bulk compression of pharmaceutical excipients: Evaluation of mechanical properties 

# data[].attributes.body
Muhd. Nazril Hafiz Bin Saidatul Nizam (58836)
Zul Zaffri Bin Mustafa (59260)
Reference link: https://www.sciencedirect.com/science/article/pii/S0032591007004883

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CASE STUDY : Reproducible Molecularly Imprinted Piezoelectric Sensor for Accurate and Sensitive Detection of Ractopamine in Swine and Feed Products

# data[].attributes.subject
CASE STUDY : Reproducible Molecularly Imprinted Piezoelectric Sensor for Accurate and Sensitive Detection of Ractopamine in Swine and Feed Products

# data[].attributes.body
Muhd Ashraf bin Anawar (56880)
Muhammad Shahid bin Mansor (58844)

This case study describes the development of a reproducible molecularly imprinted piezoelectric sensor for the accurate and sensitive detection of ractopamine (RAC). Ractopamine (RAC) is an artificially synthesized β-adrenergic agonist, which was originally used as a bronchial dilating agent for the treatment of pulmonary disease and asthma. The synthesized molecularly imprinted polymer (MIP) was directly immobilized on the surface of a quartz crystal microbalance (QCM) Au chip as the recognition element. The experimental parameters in the fabrication, measurement and regeneration process were evaluated in detail to produce an MIP-based piezoelectric sensor with high sensing capability. The developed piezoelectric sensor was verified to perform favorably in the RAC analysis of swine and feed products, with acceptable accuracy (recovery: 75.9–93.3%), precision [relative standard deviation (n = 3): 2.3–6.4%], and sensitivity [limit of detection: 0.46 ng g−1(swine) and 0.38 ng g−1(feed)].

This portable MIP-based chip for the piezoelectric sensing of RAC could be reused for at least 30 cycles and easily stored for a long time. These results demonstrated that the developed MIP-based piezoelectric sensor presents an accurate, sensitive and cost-effective method for the quantitative detection of RAC in complex samples. This research offers a promising strategy for the development of novel effective devices used for use in food safety analysis.

A reproducible molecularly imprinted piezoelectric sensor that allows for the accurate, sensitive and quantitative detection of RAC in swine and feed samples has been successfully developed. The synthesized RAC imprinted material, which is directly immobilized on the piezoelectric chip as the recognition element, exhibits remarkable binding affinity to the target RAC. The developed piezoelectric sensing chip is portable, can be reused for at least 30 times and easily stored for a longtime, suggesting its potential value in the on-site, reproducible, and realize low-cost determination of contaminants in food products. This research has promoted further integration of molecular imprinting and piezoelectric sensing techniques and expanded their application to the development of new strategies and devices in the field of food safety.

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EMPIRICAL OBSERVATIONS ON THE SENSITIVITY OF HOT CATHODEIONIZATION TYPE VACUUM GAGES

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EMPIRICAL OBSERVATIONS ON THE SENSITIVITY OF HOT CATHODEIONIZATION TYPE VACUUM GAGES

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Giri Anak Jamar (56045)

Standly Anak James (5799)

The hot cathode ionization gage (hereinafter called ion gage) is the most widely used device for measuring pressures of less than (1×10⁻³ torr). A given ion gage will be usable over five to seven decades of pressure. But, in various forms, ion gages can span the pressure range from (1×10-1) to (1×10- 13) torr. In operation, the ion gage creates tons by electron bombardment of the gas whose pressure is to be measured. The ratio of the ion current to the electron current is then divided by a specific quantity, the gage sensitivity, to give the gas pressure. The gage sensitivity is a function of several variables, each of which must be known or controlled. The gage configuration and electrical parameters must be known. The gage must be properly mounted in (or on) the vacuum system, and finally, the nature of the gas within the system must either be known or assumed. A study of empirical methods of predicting the relative sensitivities of hot cathode ionization gages is presented. Using previously published gage sensitivities, several rules for predicting relative sensitivity are tested. The relative sensitivity to different gases is shown to be invariant with gage type, in the linear range of gage operation. The total ionization cross section, molecular and molar polarizability, and refractive index are demonstrated to be useful parameters for predicting relative gage sensitivity. Using data from the literature, the probable err or of predictions of relative gage sensitivity based on these molecular properties is found to be about 10 percent. A comprehensive table of predicted r elative sensitivities, based on empirical methods, is presented. Over a wide range of pressures, the sensitivity is independent of pressure. However, at very low pressures, residual currents create an apparent pressure dependence. Also, at high pressures, unacceptable sensitivity variations, called gage saturation, occur. The useful pressure range of the gage is taken to be that portion over which these nonlinearities are small. For a specific gage and a specific gas environment, the sensitivity also depends on the electrical parameters. The electrical parameters are defined as the voltages applied to the various elements of the gage, and the currents Clowing between the elements. The magnitude of the currents influences the sensitivity only slightly. The maineffect is a reduction of the useful range of the gage with increasing electron current. Increasing the electron current will cause gage saturation to occur at lower pressure. The sensitivity, of course, varies with the gas. For a given gage, the gas identity and the applied voltages are the primary variables effecting the sensitivity. The primary interest of this report is the gage sensitivity S, and the manner in  which S varies with the gas environment within the gage. The scope of this report is restricted to those conditions under which the gage, the gas, and the voltages applied to the gage are the only significant variables affecting the gage sensitivity. Gage Classification Ion gages are available in a wide variety of configurations or geometries. They may be classified into types, according to a design principle. The type is characterized either by the design or the inventor's name. Examples of this would be triode, inverted triode or Bayard-Alpert, and Scultz-Phelps. A gage type may be further divided into subgroups called mcxlels. Usually, several models of a given type exist. They are characterized by a number, or a manufacturer's name and number. In this report, the words type and model are used in the senses just defined. The sensitivity to nitrogen for various gage types will vary from O. 5 to 20 torr - 1, due to variations in gage geometry and applied voltages. The variation of sensitivity for a given gas among various gage models of the same type will be of the order of 50 percent. For apparently identical gages of the same model, the variation will be about 20 percent because of slight variations in geometry. Some gages have multiple filaments; here, due to small differences in position, the variation of sensitivity with different filaments may be 10 percent.

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Case Study on Validation of Aerodynamic Downforce Using Micro-Measurements Strain Gauges

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Case Study on Validation of Aerodynamic Downforce Using Micro-Measurements Strain Gauges

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Nur Sahira bt Abg Abd Khaled (59002)
Evyceonna Ida anak Jilom (58586)

The Challenge: The 2015 Formula SAE season will be a millstone for the University of Florid’s team, marking the first time in team history that an aerodynamics package is implemented on its prototype vehicle. In simulations the addition of the aerodynamics package, which consists of front and rear airfoils, has been shown to improve cornering acceleration by over 10%. Before the May kick-off of the Formula SAE season in Michigan, the team needed to validate the forces generated by the addition of the aerodynamics package in order to improve the overall balance and performance of the suspension system.

The Solution: Strain gauges were attached to the rear wing supporting rods to measure the drag and lift forces created by the rear airfoil. Additional strain gauges are used to measure the increase in the force provided by the tires that were fitted to the pull rods at each corner of the car. Strain gauge transducer has fast speed to respond to the system. Besides that, it has high output signal strength. The change in the resistance in response with the strain of the material will provides the electric signal to the system.

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Case Study: Flexible Hydrogel Capacitive Pressure Sensor for Underwater Applications

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Case Study: Flexible Hydrogel Capacitive Pressure Sensor for Underwater Applications

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Ria Pavia Anak Jelie (57707)
Azzaiah Alphonsus Jenau Anak Steward (58504)

Hydrogels are three dimensional crosslinked networks of hydrophilic polymers capable of retaining large volumes of water. It features a simple design of hydrogel thin film sandwiched between two gold electrodes. They are either chemically or physically crosslinked and possess unique structural and mechanical properties that can be tailored to specific requirements. These tunable soft hydrogels can be used as a dielectric layer between two electrodes to fabricate capacitive pressure sensors. These hydrogel-based sensors find applications as soft actuators, transducers, tactile and chemical sensing, etc. Owing to their water-retaining property and stability within water, hydrogel based capacitive sensors can be employed for sensing underwater flows.

In addition, the excellent acoustic impedance match to water makes them favourable as capacitive pressure or acoustic transducer. Underwater sensing faces certain limitations such as robustness of sensors in harsh environments, biofouling, corrosion, and inability to sense over large areas for high throughput sensing. An array of hydrogel based capacitive sensors with patterned electrodes presents a good prospect for constructing surface mountable, flexible smart skins for underwater vehicles.

Dimethylacrylamide (DMAA) based hydrogels have been widely investigated for biomedical and pharmaceutical applications because of its hydrophilic and biocompatible nature with associative properties. These hydrogels, when synthesized by self-crosslinking in the presence of free radical initiators, exhibit excellent toughness and extensibility while having high swelling. These mechanical properties and the hydrophilic nature of DMAA are highly desirable to develop a sensor for underwater applications. Moreover, the crosslinking conditions are mild at room temperature. However, DMAA polymer hydrogel based capacitive pressure sensor has not been developed in the past. A thin film of hydrogel was prepared and placed between two chromium/gold (Cr/Au) electrodes to develop a simple, flexible yet robust capacitive pressure.

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Case Study: An Experimental Method Of Measuring The Confined Compression Strength Of Geomaterials.

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Case Study: An Experimental Method Of Measuring The Confined Compression Strength Of Geomaterials.

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1) Fionshe Anak Thomas (56004)
2) Anilsia Dayun anak Mang (55493)

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Bulk Modulus can  Compromise Response Time of a System

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Bulk Modulus can  Compromise Response Time of a System

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Nur Najihah binti Mohd Azhar 58994
Siti Shuhadah binti Shamsul Anuar 59203

Despite the frequent assumption that hydraulic fluid is incompressible, the fact remains: All fluids have some degree of compressibility. Granted, fluid compressibility may be neglected in systems that do not require tight control of response and where operating pressure and fluid volume are moderate. However, when applying high pressure to a large volume of fluid, a significant amount of energy can be expended to compress the fluid — essentially squeezing the fluid's molecules closer together.
The result can be delayed response — a loaded actuator may not move until upstream fluid has been compressed, and the energy stored in the fluid may cause the actuator to continue moving after its control valve has closed. Bulk modulus is a property that indicates the compressibility of a fluid. With many of today's hydraulic systems operating at pressures 5000 psi and higher, ignoring bulk modulus can compromise response time of a system.
Applied pressure should directly affect the action of the system rather than compress the fluid. This is why it is so important to design systems with as little fluid as possible beween the control valve and the actuator.

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Rachel Chai Sze Chi 57671 & Richard Chin Kai Yu 57710 

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Rachel Chai Sze Chi 57671 & Richard Chin Kai Yu 57710 

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Case Study: Bulk modulus cell based on fiber-optic displacement sensor

This case study presents a modification to a conventional bulk modulus cell by using fiber-optic displacement sensor. Three conventional methods for measuring the deformation of the active element in bulk modulus cell are, LVDT sensor, resistance strain gauge, and capacitance sensor.

The main advantage found with the use of fiber-optic technique is that it allows the bulk modulus cell to be more durable in corrosive and explosive environment. Furthermore, the transducer can be used to measure static and dynamic pressure in electrically conducting environments or in fluid of high viscosity. It is electrically passive and can easily be adapted for remote operation, including direct coupling to a fiber-optic data transmission network.

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Case Study:Comparison of hot and cold ionization gauges

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Case Study:Comparison of hot and cold ionization gauges

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George Luang Anak Jenggut (58619)
Maximillian Guang Anak Manggas (58702

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Pressure Measurement by Hot and Cold Cathode Gauges following a Pumpdown V1

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Study of a Pressure Transmitter Using an Improved Inductance Bridge Network and Bourdon Tube as Transducer

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Study of a Pressure Transmitter Using an Improved Inductance Bridge Network and Bourdon Tube as Transducer

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Tan Chuan Ser 58062
Allan Pui Fui Ching 59268

A Bourdon tube is a mechanical-type pressure sensor. It is generally used in a local pressure indicator and display. Hence, a special technique is needed to transmit to and display the reading of a Bourdon gauge at a remote distance. In this paper, an improved inductance bridge-type technique has been developed to convert the Bourdon tube movement into an electrical current signal which can be transmitted to a remote indicator. A bent ferromagnetic wire attached to the tip of the Bourdon tube acts as a sensing element of pressure. The movement of the wire as a result of pressure variations inside an inductive pickup coil changes the self-inductance of the coil with the changes in pressure. An improved inductance bridge network has been utilized to measure the self-inductance of the coil more accurately when compared with the readings by an LCR meter. It has been observed that the variation of the self-inductance of the pickup coil as well as the variation of the transducer and transmitter outputs with pressure has very good linearity and repeatability.

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Case study: Inductive Pressure Transducer

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Case study: Inductive Pressure Transducer

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Nur Syahirah Binti Salimin 59016
Nurul Fastifa Bt Ab Sani 59085

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Case Study: A Dynamic Calibration Method For Pirani Gauges Embedded in Fluidic Networks.                                  Affy Maxmiano Anak Junih (55324)       

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Case Study: A Dynamic Calibration Method For Pirani Gauges Embedded in Fluidic Networks.                                  Affy Maxmiano Anak Junih (55324)       

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Challenges:

PIRANI gauges, which transduce gas pressure into changes in electrical resistance, have been widely used in microsystems. Typically, the Pirani gauge has a resistive heating element that is suspended on a thermally isolated membrane. The heat generated in the operation of the Pirani gauge flows across a sense gap beneath the membrane, to a substrate, which serves as the heat sink. As the vacuum level or gas pressure changes in the sense gap, the resulting change in thermal conductance causes a change in the temperature of the membrane (or alternatively, a change in the power level necessary to maintain it at a fixed temperature). The change in temperature can be detected by the resistive heating element, or alternatively by another resistor.The structure and operation of a typical Pirani gauge are favored as embedded sensing elements within microfluidic systems and micromachined pumps, because of simple fabrication requirements that are relatively easy to integrate into other manufacturing processes.

Solution:

For the accurate measurement of pressure with a Pirani gauge, its resistance variation must be calibrated over the operating pressure ranges. This is necessary because process-induced sample-to-sample variations in dimensions and material properties can cause variations in the response. A Pirani gauge is typically calibrated by varying the pressure in the sense gap. In most cases, the structure is designed so that the heat loss from the suspended heating element is dominated by thermal conduction through the sense gap; i.e., the heat losses to the exterior of the structure, and the conductive heat losses along membrane on which the Pirani gauge is suspended, are relatively small. During calibration, the interior of the membrane and the exterior of the membrane are both at a common pressure controlled by a calibration pump. In this method, the dominance of the heat loss through the sense gap is retained, and the thermal losses to the exterior are accommodated in the calibration. For this paper, this calibration procedure is namedstatic calibration. In contrast, when the Pirani gauge resides on a thermally-insulating membrane which completely separates the underlying sense gap from the exterior environment static calibration is likely to be inaccurate because of the lack of direct access to – and control of the pressure in – the sense gap. Further, if the interior pressure is low, the heat losses to the exterior could represent a significant un-calibrated component.

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Case study on Piezoelectric Flooring: Harvesting Energy Using Footsteps

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Case study on Piezoelectric Flooring: Harvesting Energy Using Footsteps

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Brenda Santiago Anak Paris (58513)
Lolia Anak Jonathan Jua ( 56496)

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Alvin Tingai Thomas (55427)
Joana anak Peter (56220)

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Studyof the Humidity Effect on the Stabilityof a Capacitive Ceramic Pressure Sensor 

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Studyof the Humidity Effect on the Stabilityof a Capacitive Ceramic Pressure Sensor 

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Yii Seng Lung(58344)
Ngo Fang Jun( 56943)

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Case Study : Major Cause of Failure in Ionization Gauge (Bayard-Alpert Gauge)

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Case Study : Major Cause of Failure in Ionization Gauge (Bayard-Alpert Gauge)

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Melissa Jane Anak Andrew (56592)
Marilyne Undart Anak Martin Alling (56559)

Problem
The leakage currents, a major cause of failure of the ionization gauges were of such a low order that no problems due to interelectrode shorting were encountered. This absence of leakage currents is attributed to the improved shielding of the gauge element penetrations through the envelope of the gauges. Although the leakage current was eliminated by the modified gauge structure, the gauge remained inoperative at higher pressure levels.

Solution
The output of a BAG is a very small current and even relatively small leakage currents can add significant errors to the measurements at low pressures. Some useful tips to reduce leakage currents include:

The area around the collector pin on the gauge must be kept clean at all times on both the air and vacuum sides of the feed through connectors.

A collector insulator shield is present in most BAG designs to avoid the development of leakage currents due to contamination of the ceramic or glass insulators with conductive layers of impurities. Internal leakage usually results from the evaporation of tungsten or thoria molecules from the filament. Do not use nude gauges that do not include such shields.

The collector terminal of glass tubulated gauges is purposely located at the opposite end of the envelope from the grid and filament conductors, and usually has a built in glass skirt that acts as a shield against contamination deposits.

It is important to use good quality leads to make connections to the controller. Gold plated connector pins are often used, and assure that the gauge tube can be easily removed from the connector after extended use.

Changes in the glass conductivity can occur at the elevated temperatures used to make some pressure measurements. For such situations, envelopes of metal and alumina are recommended.

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Case Study on Bulk-Modulus Sensor sensing bulk modulus of fluid

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Case Study on Bulk-Modulus Sensor sensing bulk modulus of fluid

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ALYSSA ASONG ANANTHAN 55430
AMIRUL AMIEN BIN ARIFIN 58450

One application that smart materials may have a significant impact in is the measurement of bulk modulus. Accurately knowing the bulk modulus of a fluid is very important in many hydraulic applications. The absolute bulk modulus has a major effect on the position, power delivery, response time, and stability of virtually all hydraulic systems. The focus of this research is to develop a novel sensor to measure bulk modulus of a fluid instantaneously. The work tested three different strategies to determine the bulk modulus of a fluid within a system. The first approach is to develop a theoretical model to extract the bulk modulus of the fluid system by knowing the excitation voltage and measuring the strain. The results indicate that matching the stiffness of the actuator to the stiffness of the fluidic system is critical in obtaining a high sensitivity to the bulk modulus measurement. The second approach determines the frequency response functions by performing transfer function measurements using an impulse response test. In this test, the transfer function of the pressure response with respect to the applied force is measured. By doing so it is possible to extract information about the properties of a fluid. The tests are performed on three different fluids: water, hydraulic oil and hydraulic oil with bubbles. The results indicate that magnitudes of the peaks (at 1400 Hz) were larger and sharper for water compared to oil. Also, the magnitude of the peaks (at 1400 Hz) in the case of hydraulic oil with bubbles was not only reduced but also occurred at a lower frequency compared to the other two fluids. The third approach uses speed of sound measurements to determine the bulk modulus of the fluid in real time. The results indicate the theoretical values are reasonably close to the actual bulk modulus values. Also, the hydraulic oil contaminated with bubbles has a lower bulk modulus value compared with the pure hydraulic oil.

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Ismul A'zam Bin Hisam (58663)
Luqman Hakim Bin Mat Fouad (58691

The development of the SSC Collider Dipole and virtually all superconducting magnet projects worldwide, would be greatly aided by the realization of load measuring instrumentation which could be installed at various locations within superconducting magnet structures. To be of true value, such instrumentation must not perturb the superconducting
magnet structure itself. To minimize perturbations, it would be necessary to develop an extremely thin load cell. If a thin, accurate load measuring device could be developed, such a device might also have significant commercial applications.

A load cell, a device which measures mechanical load, may be designed based on the parallel plate capacitor. In a capacitor load cell, the capacitance will change as the load cell is loaded. Primarily the change in capacitance corresponds to the change in plate separation and plate area. The change in plate separation is related to the modulus of elasticity of the dielectric material. It should be possible to construct a capacitor gage based on the bulk modulus effect. This could be achieved by causing a condition of spherical or hydrostatic stress to exist within
the dielectric material. This condition could be established by using a constrained fluid or a
plastic dielectric. Fermilab has been developing the Bulk Modulus Gage over the past year. During this
time, we have achieved a more thorough understanding of the gage's properties. In addition,
we have gone far toward developing the readback electronics and making the gage's more convenient and reliable to use. Our initial work was conducted with a classic parallel plate configuration. Since our gage's displayed fairly low capacitance, on the order of a few hundred picofarads, we noticed a significant signal contribution due to the existence of an external shunt capacitance circuit.

Bulk Modulus Capacitor Load Cells are apparently a new type of transducer technology. They offer the possibility of providing instrumentation to study superconducting magnet structures. In addition, important commercial applications are possible. However, more work needs to be done.

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Walter Xavier Anak Ngadan 58246
Jacquelyn Mujan Jok 56179

In the elasto-plastic constitutive model, bulk modulus is one of the most important parameters to control the change of effective stress under undrained condition. However, the experimental research on bulk modulus of sand during liquefaction has not been conducted so far. In this paper, therefore, the bulk modulus of Toyoura sand was measured directly during liquefaction using a hollow cylindrical torsional shear testing device equipped with a volumetric strain control device. This study found that the bulk modulus corrected by membrane penetration effect during liquefaction process is constant under relatively high confining pressure, and that the stress dependency of bulk modulus during liquefaction process is different from that during swelling process.

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Case Study: Wave Power Generation by Piezoelectric Sensor Attached to a Coastal Structure                            Barbra Basy Anak Cassidy Gundi 58505Emily Rinta Anak Lembang 58575

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Case Study: Wave Power Generation by Piezoelectric Sensor Attached to a Coastal Structure                            Barbra Basy Anak Cassidy Gundi 58505Emily Rinta Anak Lembang 58575

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By installing the sensor to the structure, waves will hit the piezoelectric sensor to generate wave energy; at the same time, the structure acts as a wave breaker. This technique can be applied to various coastal structures to converge the functions of renewable energy generator and the wave reducing structure. Hydrographic analysis of this technique has been conducted by hydraulic model experiment using 2D wave flume and confirmed that the wave pressure and voltages maximize when higher wave with longer period of wave induces.

A piezoelectric sensor is a sensor that generates a mechanical strain when an external force is applied or a deformation occurs when a voltage is applied to the sensor. The piezoelectric sensor is applied in various purposes in many industries and used widely such as medical industries, automobile industries, and information communication industry. This piezoelectric sensor determines the energy level from the external force condition, and it is expected to collect high energy in the ocean where the main external force is expected to be collected. In particular, the coastal structure protects the harbor facilities from the high waves.

The piezoelectric sensor can convert the mechanical energy and the electric energy from the functional aspect, and it is possible to directly apply the unimorph piezoelectric body to the power generation device for energy harvest; however, since energy efficiency is low, attempting to apply it to the electricity generation was low . Nonetheless, this study investigates the generated energy due to the external force change through the fabrication of the power panel with high-energy element and the coupling of multiple devices. This unimorph-type sensor generates electric output by the piezoelectric effect of ceramics using external vibration energy.

In this study, the efficiency and power of the generated energy were investigated by measuring the wave pressure and voltage according to the wave activity using the piezoelectric element and the harvesting system which are mechanical energy conversion devices. Piezoelectric sensor devices are characterized by the momentary energy generation due to external force changes, and irregular waves are suitable for application to coastal structures which continuously invade. As a result, the wave pressure and voltage were increased with increasing wave energy, and it was confirmed that maximum 7.75 kPa and 11.24V were calculated within experimental conditions. Under these conditions, the generated power is about 12.35mW, and when applied to the actual sea area, the amount is increased by the super compact rule, and it is considered to play an important role as a substitute resource of the compost fuel.

References

Kim, K. H. (2018). Wave Power Generation by Piezoelectric Sensor Attached to a Coastal Structure. Journal of Sensors, Volume 2018, Article ID 7986438, 7 pages https://doi.org/10.1155/2018/7986438

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Case Study - Bolt-on Strain Gauge Sensors : Real World Application in the Mining Industry

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Case Study - Bolt-on Strain Gauge Sensors : Real World Application in the Mining Industry

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Nur-Adli Bin Razali (57391)
Siti Nurkhaleeda Binti Muhammad Zabidi (59200)

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Case study on capacitive pressure sensor for medical liquid-level applications

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Case study on capacitive pressure sensor for medical liquid-level applications

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Monalisa Johadin@Alung 58767
Erra Nadzira Binti Hasnan 55893

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SHAWN IANNU ANAK GUILLAN (57832)
ELISTER LOUIS ANAK DAMPA (55861)

PROBLEM

The ratio of lateral to vertical stress at zero lateral strain (K0 ) is a soil characteristic that is important in several geotechnical applications. At present, no unanimity exists as to how K0 should be calculated or how it is influenced by stress history. The uncertainty regarding this soil characteristic may be reduced through improved measurements. The "at rest" lateral stress ratio for soils K0 is used in retaining wall and deep foundation analyses and estimates of the loads on buried pipes, and has been shown to influence the shearing resistance of soils. K0 also affects the bearing capacity and settlement of shallow foundations, but it is seldom used. Some uncertainty exists about how to estimate or measure this soil characteristic, and the uncertainty is greatest in very loose soils, compacted fills, and over consolidated sediments and residual soils.

SOLUTION
To calculate obtain data require to study the lateral strain the varying soli type is tested under highly compressed condition with a confined compression testing apparatus which is made up of a bulk compression apparatus.From the results they discover the soil characteristics whether it is suitable for the intended application

Case study is done based on  experiment conducted  by L. w. ZACHARY AND R. A. LOHNE

S

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Behaviors of capacitive and Pirani vacuum gauges: Case study on time effect

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Behaviors of capacitive and Pirani vacuum gauges: Case study on time effect

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1.Abang Ahmad Dzulfakhri Bin Abang Hastanal Madani (58385)
2.Mohd Nur Azmeer Bin Made(58760)

In this case study, using McLeod’s barometer, the deviation of capacitive and Pirani vacuum gauges is investigated at different time intervals in the middle vacuum range, and it is determined that the vacuum gauge faces a serious deviation from the actual calibrated amount for upper and lower ranges of middle vacuum in the same working pressure range over time.

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Behaviors of capacitive and Pirani vacuum

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David Alvin anak Patrick 58537
Mohd Azri bin Roslan 58744

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RAYNOLD ANAK NIGEL (55002)

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Case study of bulk compression testing of peaches to access textures

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Case study of bulk compression testing of peaches to access textures

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Jonathan anak Peter Giman (56229)
Estefan Othniel Lisut (55897)

https://eurekamag.com/pdf/000/000306311.pdf

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Domion Ding Tom 58557 Franklin Lingga 58616

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Domion Ding Tom 58557 Franklin Lingga 58616

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Bulk properties of open cell polyurethane foam are studied in a hydrostatic compression experiment under strain control. A linear region of behaviour is observed in the stress-strain curve, followed by a non-monotonic region corresponding to a negative incremental bulk modulus. The bulk modulus in the linear region is in reasonable agreement with the value calculated from compressional Young’s modulus and Poisson’s ratio. The linear region of behaviour in hydrostatic compression corresponds to less than half the axial strain range observed in axial compression.

Hydrostatic compression of open cell foam discloses a linear range of behaviour. The bulk modulus is in reasonable agreement with the value calculated from Young’s modulus and Poisson’s ratio assuming isotropy. The linear region for hydrostatic compression corresponds to about 7% volumetric strain, or 2.3% axial strain, which is in contrast to uniaxial compression for which the linear range corresponds to 5% or more axial strain. Beyond about 20% volumetric strain in hydrostatic compression, the pressure-volume curve has a nonmonotonic region indicative of a negative incremental bulk modulus.

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Case Study: Studies on Characteristics of Axial Emission Ionization Gauge

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Case Study: Studies on Characteristics of Axial Emission Ionization Gauge

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Yong Tze Jack 58354
Hong Wei Hao 56124

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Case Study: Study on MEMS Capacitive Differential Pressure SensorRaja Nurul Amira binti Raja Jamam 50905Zulaikha binti Hamdan 54309

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Case Study: Study on MEMS Capacitive Differential Pressure SensorRaja Nurul Amira binti Raja Jamam 50905Zulaikha binti Hamdan 54309

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Problem:

The design and fabrication of MEMS capacitive differential pressure sensor is reported. Silicon membrane is used as movable electrode. Gold metal film on glass is used as fixed electrode. Anodic bonding is used to bond together the silicon and glass to form the capacitive pressure sensor. The measurement capacitance of the sensors is 5.37 pF at an applied pressure of 0 kPa and 7.26 pF and the full operating range of 40 kPa.The ratio of changed to initial capacitance was 0.35. The error of the MEMS capacitive pressure sensor is less than 4‰ full-scale (FS) by using quadratic curve fitting which can meet most application requirements.

Solution:

Capacitive pressure sensor is compose of a moveable electrode (made by silicon membrane) and the fixed electrode (metal film on substrate). Capacitive pressure sensor been choose because it performance are better in temperature drift, long term stability. Its suitable for static and dynamic pressure. Many company and research focus on capacitive pressure sensor. Absolute pressure sensor of VTI company for barometric pressure measurement and altimeter application and gauge pressure sensor of Fuji company for pressure transmitter all use the MEMS capacitive pressure sensor as the core sensitive devices.

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Two wire pressure Transmitter using Bourdon tube pressure sensor and LVDT-An advance pressure transmitter
the bourdon tube is one of the most widely used element in detection of pressure of the fluid. it was invented in 1849 by Sehins and marketed in 1850 by E.Bourdon, it was then developd to detect pressure from 1 psi to 140,000 psi.
In industries that manufacture Bourdon tubes, tip travel is obtained from experimental data in the absence of a mathematical model. This further prompted the development of an analytical solution for tip travel in a Bourdon tube.  With today's micro-chip technology, many people think that the trend for pressure gauges is moving in the direction of the electronic transducer. Surprisingly, precision pressure gauges demonstrate consistent and accurate behavior using Bourdon tube technology. As a result, the demand for Bourdon gauges is quite significant. With the development of different pressure transducers ,different  techniques  have  been  developed  to

measure  pressure  sitting  at  the  control  room  which  is

located  in  a noise  and hazard  free atmosphere,  far away

from the process plant. That is, the pressures of the process

sensed  by  the  transducer  at  the  plant  site  are  to  be

transmitted  to  the  control  room  for  monitoring  and

controlling  purpose.  Two  wire  pressure  transmitter  is

generally used for this purpose. The output of the two wire

pressure transmitter may  be pneumatic signal  between 3 –

15 psi, voltage between  0 – 5  V or  0 – 10  V and current

between 4 – 20 mA  where the lower range corresponds to

minimum  pressure  sensed  and  20  mA  corresponds  to

maximum  pressure.  These  outputs  of  the  pressure

transmitter are not affected by the load impedance variation

and supply voltage fluctuations. There are different types of

pressure  transmitters  developed with  the  advancement  of

research.  The  output  of  pneumatic  pressure  transmitter   such  as  flapper  –  nozzle  assemble,  is  nonlinear.

Linear range can be obtained from the normalized response

curve  for specific flapper movement and  nozzle  diameter .  Torque  balance  type  transmitter  consists  of flapper  nozzle,  electromagnetic  relay,  feedback  bellows, diaphragm  and  torque  tube.  Feedback  bellows  used  here reduces  the  measurement  error.  Electrical  type  pressure

transmitter consists  of  a  comparator  and  an

amplifier. Using this type of transmitter, better accuracy in

pressure  measurement  can  be  achieved.  Since  Bourdon

tubes can measure pressure in the range of almost

100,000 psi (700 MPa), it can be used to measure pressure

in process industries. In this paper, how industrial pressure

can be measured and controlled using Bourdon tube, LVDT

and  two  wire  pressure  transmittershas  been

explained  clearly  with  experimental  result.  Also  the

response of the system for different excitation frequencies

has  been  found  experimentally.  Section  II  explains  the

discussion on how a Bourdon tube in connection with an

LVDT  gives  electrical  output  corresponding  to  specified

range of pressure.

p roblem:
1.general solution are too complex to handle mathematically
2.had to limit their derivations to those giving mathematically soluble equation
3. limiting cases where particular ratios approaching zero or infinity.

Solution:

1.The proposed work consists of three units, two of which are

transducers  and  the  other  is  a  transmitter.  The  two

transducers are Bourdon tube  pressure gauge  which is the

primary  transducer  and  LVDT  which  is  the  secondary

transducer

2.

The schematic diagram of an LVDT is shown in Figure 2(a)

and (b). LVDT  is a transducer which converts  mechanical

displacement into output  electrical signal corresponding  to

the  input  displacement.
3  the  proposed  pressure  measurement  system  is  useful  to

measure pressure both on spot  and at remote  place where

control room is situated

advantages:

1. system  consists  of  two-wire

transmitter,  no noise  or electromagnetic  interference  may

affect the measuring procedure.
2. it  can  be  used  for  wide  range  of application.
3.provide less error

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Study of the Humidity Effect on the Stabilityof a Capacitive Ceramic Pressure Sensor Yii Seng Lung(58344) Ngo Fang Jun( 56943)       pdf refer to link :https://www.radioeng.cz/fulltexts/2012/12_01_0201_0206.pdf

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Study of the Humidity Effect on the Stabilityof a Capacitive Ceramic Pressure Sensor Yii Seng Lung(58344) Ngo Fang Jun( 56943)       pdf refer to link :https://www.radioeng.cz/fulltexts/2012/12_01_0201_0206.pdf

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case study on Capacitive Ceramic Pressure Sensor

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Development of Bulk Compression Measurement for Nonwoven Sheet of Electrospun Nanofibers

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Development of Bulk Compression Measurement for Nonwoven Sheet of Electrospun Nanofibers

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JIOVANNY ANAK JUTIM 56219
AKRIMI MISWA BT ABDULLAH 45442

The sample stage should have small displacement under compression load, which should be subtracted from the displacement of the nanofiber sheet. The MD of the three sample stages measured by using a disk indenter and ball indenter under a compression load of 1 N is shown in Figure 4. The MDs obtained by using the disk indenter indicated a larger value and deviation than those obtained using the ball indenter. The MDs obtained by the disk indenter were expected to be lower than that of the ball indenter, because the contact area of the disk indenter was larger than the ball. We considered that the MD of the disk indenter includes error caused by the unparallel condition between the disk indenter and sample stages. In addition, SUS-304 should have the smallest deformation under compression load according to the elastic modulus of the material. However, experimental results obtained using the disk indenter showed discrepancy from the calculation results. The results indicate that the ball indenter is more suitable than the disk indenter for measuring small displacement for nanofiber sheets. When the effect of ball diameter on the MD of the sample stage was considered, no significant difference was observed and the difference in MD among the three stages was within 0.5 mm when balls of 5 and 10 mm in diameter were used. Therefore, the spherical ball indenter with a 5 mm diameter was examined for the compression of nanofiber sheets. Furthermore, although the SUS-304 and brass sample stages show smaller MDs than the aluminium one, the aluminium stage showed a higher efficiency for collecting fibers on the stage during spinning. Therefore, the aluminium stage was selected. The load–displacement curve of the nanofiber sheet was calculated in a manner that its displacement of the same corresponding load of the aluminium stage was subtracted from that of the nanofiber sheet on the stage.

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First Principles Estimation of Bulk Modulus and Theoretical Strength of Titanium Alloys

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First Principles Estimation of Bulk Modulus and Theoretical Strength of Titanium Alloys

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Gloria Elaine John (58623)
Nova De Claudia Tay (58923)

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Case study :Strain gauge pressure tranducer
Nurshada Nabiha binti Ibrahim 59054
Wan Normardhiah Binti Wan 'Aizuddin 59245