Search results

Physical contact and traditional sensitive structure Physical contact and traditional pressure-sensitive structures typically do not operate well in harsh environments. This paper proposes a high-temperature pressure measurement system for wireless passive pressure sensors on the basis of inductively coupled LC resonant circuits.

This paper begins with a general introduction to the high-temperature pressure measurement system, which consists of a reader antenna inductively coupled to the sensor circuit, a readout unit and a heat insulation unit. The design and fabrication of the proposed measurement system are then described in detail.

A wireless passive pressure sensor without an air channel is fabricated using high-temperature co-fired ceramics (HTCC) technology and its signal is measured by the designed measurement system. The designed heat insulation unit keeps the reader antenna in a safe environment of 159.5°C when the passive sensor is located in a 900°C high-temperature zone continuously for 0.5 h. The proposed system can effectively detect the sensor’s resonance frequency variation in a high bandwidth from 1 to 100 MHz with a frequency resolution of 0.006 MHz, tested from room temperature to 500°C for 30 min.

Expensive and bulky equipment (impedance analyzers or network analyzers) restrict the use of the readout method outside the laboratory environment. This paper shows that a novel readout circuit can replace the laboratory equipment to demodulate the measured pressure by extracting the various sensors’ resonant frequency. The proposed measurement system realizes automatic and continuous pressure monitoring in a high-temperature environment with a coupled distance of 2.5 cm. The research finding is meaningful for the measurement of passive pressure sensors under a wide temperature range.

Each of the four objectives can be applied within the military training environment. Military training often requires that soldiers achieve specific levels of performance or proficiency in each phase of training. For example, training courses impose entrance and graduation criteria, and awards are given for excellence in military performance. Frequently, training devices, training media, and training evaluators or observers also directly support the need to diagnose performance strengths and weaknesses. Training measures may be used as indices of performance, and to indicate the need for additional or remedial training.

The paper aims to highlight a wireless pressure-sensitive micro-device with high pressure sensitivity and accuracy. It is based on the partially stabilized Zirconia (PSZ) ceramic material which is capable of excellent elasticity and robustness.

The paper begins with a general introduction to the wireless interrogating method and then the fabrication processes of the device using high temperature co-fired ceramic (HTCC) technology are described in detail.

A passive wireless micro-device made from a novel material-PSZ ceramic on pressure monitoring is fabricated and tested and the authors proved that the device possesses an advantages over some proposed wireless sensors on interrogating distance. The pressure sensitivity of the device is 336 kHz/bar at readout distance 2.5 cm and that is an excellent property.

The paper shows a new design scheme for wireless pressure measurement. The future application of the wireless device indicates the problem on external packaging and wire connection could be avoided. The allowable interrogation distance between the device and readout circuit reaches 2.5 cm which is mentioned for the first time so far. The distance is long enough to insert a thermal insulation material which can protect the vulnerable readout circuit from harsh environment, so the research finding is meaningful for the modern measurement technology.

Modern industry and domestic users continue to demand increasing quantities of coated products. Since price, performance and appearance are all dependent upon the thickness of these coatings, it is mandatory to measure thicknesses as fast, as accurately and as economically as possible. Modern technology has largely solved the mechanics, or more correctly the electronics, of the actual measuring process, but now most ordinary users find problems in how best to use the results for the greatest overall benefit. The Beta Backscatter method of measurement applied to the production and use of printed circuits is taken as an example of what can be done with a little more knowledge, perhaps a little beyond that of simple coating thickness measurement.

Explores a PC‐based multi‐function virtual test and measurement system for automated manufacturing lines. The system includes single and dual channel oscilloscopes, a 50MHz spectrum analyzer, a multifunctional digital voltmeter and a 20MHz digital frequency meter. Outlines the benefits of the system including the availability of high‐performance instruments anywhere there is a PC cost saving and space saving. It also has considerable potential training test and maintenance personnel.

The purpose of this paper is to conduct a review of types of tomographic systems that have been widely researched within the past 10 years. Decades of research on non-invasively and non-intrusively visualizing and monitoring gas-liquid multi-phase flow in process plants in making sure that the industrial system has high quality control. Process tomography is a developing measurement technology for industrial flow visualization.

A review of types of tomographic systems that have been widely researched especially in the application of gas-liquid flow within the past 10 years was conducted. The sensor system operating fundamentals and assessment of each tomography technology are discussed and explained in detail.

Potential future research on gas-liquid flow in a conducting vessel using ultrasonic tomography sensor system is addressed.

The authors would like to undertake that the above-mentioned manuscript is original, has not been published elsewhere, accepted for publication elsewhere or under editorial review for publication elsewhere and that my Institute’s Universiti Teknologi Malaysia representative is fully aware of this submission.

The conventional strain gauge type pressure sensor suffers in static testing of engines due to the contact transduction method. This paper aims to focus on the concept of non-contact transduction-based pressure sensor using eddy current displacement sensing coil (ECDS) to overcome the temperature limitations of the strain gauge type pressure sensor. This paper includes the fabrication of prototypes of the proposed pressure sensor and its performance evaluation by static calibration. The fabricated pressure sensor is proposed to measure pressure in static test environment for a short period in the order of few seconds. The limitations of the fabricated pressure sensor related to temperature problems are highlighted and the suitable design changes are recommended to aid the future design.

The design of ECDS-based pressure sensor is aimed to provide non-contact transduction to overcome the limitations of the strain gauge type of pressure sensor. The ECDS is designed and fabricated with two configurations to measure deflection of the diaphragm corresponding to the applied pressure. The fabricated ECDS is calibrated using a standard micro meter to ensure transduction within limits. The fabricated prototypes of pressure sensors are calibrated using dead weight tester, and the calibration results are analyzed to select the best configuration. The proposed pressure sensor is tested at different temperatures, and the test results are analyzed to provide recommendations to overcome the shortcomings.

The performance of the different configurations of the pressure sensor using ECDS is evaluated using the calibration data. The analysis of the calibration results indicates that the pressure sensor using ECDS (coil-B) with the diaphragm as target is the best configuration. The accuracy of the fabricated pressure sensor with best configuration is ±2.8 per cent and the full scale (FS) output is 3.8 KHz. The designed non-contact transduction method extends the operating temperature of the pressure sensor up to 150°C with the specified accuracy for the short period.

Most studies of eddy current sensing coil focus on the displacement and position measurement but not on the pressure measurement. This paper is concerned with the design of the pressure sensor using ECDS to realize the non-contact transduction to overcome the limitations of strain gauge type pressure sensors and evaluation of the fabricated prototypes. It is shown that the accuracy of the proposed pressure sensor is not affected by the high temperature for the short period due to non-contact transduction using ECDS.

The purpose of this paper is to study a multiphase-flow instrumentation for film thickness measurement, especially impedance-based, not only for gas–liquid flow but also for mixtures of immiscible and more viscous substances such as oil and water. Conductance and capacitive planar sensors were compared to select the most suitable option for oil – water dispersed flow.

A study of techniques for measurement of film thickness in oil – water pipe flow is presented. In the first part, some measurement techniques used for the investigation of multiphase flows are described, with their advantages and disadvantages. Next, examinations of conductive and capacitive techniques with planar sensors are presented.

Film thickness measurement techniques for oil–water flow are scanty in the literature. Some techniques have been used in studies of annular flow (gas–liquid and liquid–liquid flows), but applications in other flow patterns were not encountered. The methods based on conductive or capacitive measurements and planar sensor are promising solutions for measuring time-averaged film thicknesses in oil–water flows. A capacitive system may be more appropriate for oil–water flows.

This paper provides a review of film thickness measurements in pipes. There are many reviews on gas – liquid flow measurement but not many about liquid – liquid flow.

The use of frequency output for measurement transmission remains common in the design of smart transmitters. Conventional methods of frequency generation, based on counting clock cycles, have a precision which is inversely proportional to the frequency to be generated. Consequently, frequency output precision could be much lower than the measurement precision. This paper describes a simple frequency generation technique which, when implemented in low‐cost hardware, provides a precision of 10⁻⁶ per cent for all frequencies. The method represents an intermediate non‐available frequency by dithering between two exact frequencies. Averaging over some reasonably short timescale provides the desired frequency to high precision.

The Center for Industrial Research (SI), the University of Oslo (UiO) and a group of Norwegian companies have collaborated between 1990 and 1992 in the research programme ‘Industrial Microelectronics’ with a total cost of 30 MNOK. The programme was sponsored by the Norwegian Scientific and Industrial Research Council (NTNF) as one of the twin programmes constituting a national research initiative in microelectronics. The motivation for the programme is the recognition of microelectronics as a key technology commanding the performance and market success of many of the electronics systems from the Norwegian electronics industry towards the year 2000. The main objective is to stimulate industrial innovation by developing, transferring and exploiting knowledge and methods based upon advanced microelectronics. Focused activities are silicon sensor technology, combined analogue/digital design of application‐specific integrated circuits, large scale instrumentation, sensor packaging and thermal management of electronic systems. SI is focusing on applied research, UiO on education, and collaborating Norwegian companies are using the results in their own R&D projects. It is anticipated that the research results will be fully industrialised within 3–5 years. The programme is co‐ordinated with other Norwegian government‐sponsored research activities as well as European research programmes based on microelectronics. The programme is organised in projects and monitored with a set of milestones strongly indicating the achievement of successful industrial innovation, research results of international standing and high‐quality education of key personnel for the industry. Several successful examples of the research results are highlighted: Design and process methodology for double‐sided microstrip silicon radiation sensors for detection of high energy elementary particles, silicon‐to‐silicon and silicon‐to‐thin film anodic bonding processes for sensor fabrication, combined analogue/digital application‐specific integrated circuits for front‐end instrumentation applications, packaging of radiation sensors and thermal management of electronic systems by evaporation cooling. It is concluded that the programme has successfully achieved results in harmony with the objective.