Type Of Pressure Sensor Research Articles

In Situ Calibration of Moored CTDs Used for Monitoring Abyssal Water

Abstract To monitor changes in heat content and geostrophic volume transport of abyssal water accurately, 50 moored conductivity–temperature–depth (CTD) recorders used for density measurements were calibrated in situ by simultaneous observations with accurate shipboard CTDs. Comparisons of the data from the moored and shipboard CTDs showed pressure sensitivities of 0–3 mK at 6000 dbar for the temperature sensors of the moored CTDs. From the in situ calibrations, the uncertainties of the moored CTD data for the deep ocean (≥3000 dbar) were estimated to be 0.6 dbar, 0.6 mK, and 0.0026 for pressure, temperature, and salinity, respectively, relative to the shipboard CTD reference. Time drifts of the moored CTD data, estimated from the in situ calibrations before and after 17- or 14-month mooring deployments in the deep ocean, were considerably smaller than typical stabilities as specified by the manufacturer. However, time drifts of the pressure sensors tended to be negative and the result suggests that pressure data from most present Argo floats, which use the same type of pressure sensor, may have a systematic negative bias. Time series salinity data calculated from the in situ–calibrated CTDs were slightly biased (mean of +0.0014) with respect to the shipboard CTD salinity data, based on potential temperature–salinity relationships, possibly due to a disequilibrium of the moored CTD conductivity sensors during the in situ calibrations.

The Study on Fatigue Lifetime Evaluation on the Interconnect of Diaphragm Type Pressure Sensor According to Various

The Study on Fatigue Lifetime Evaluation on the Interconnect of Diaphragm Type Pressure Sensor According to Various

A novel pressure sensor with a PDMS diaphragm

This paper describes a novel pressure sensor with a polydimethylsiloxane (PDMS) diaphragm, which is used to achieve much larger deformation than conventional silicon diaphragms under low pressure. The larger deformation of the PDMS diaphragm provides higher sensitivity than silicon-based pressure sensors because of the lower Young’s modulus of the PDMS diaphragm. The great advantage of the PDMS diaphragm with respect to sensitivity was confirmed through the use of the numerical simulation method and through the conduct of basic experiments. A carbon fibre 10μm in diameter was used to sense the strain change that had been induced on the diaphragm during its operation. The optimal position of the carbon fibre in the PDMS diaphragm was determined using the numerical analysis method. The carbon fibre was exactly formed across the Al electrodes in the diaphragm through dielectrophoresis. The replacement of the piezoresistor material provided some advantages, such as easy fabrication and a high gauge factor. Several types of pressure sensors with a PDMS diaphragm were fabricated, and the feasibility of such pressure sensors was evaluated.

1137 ダイヤフラム式圧力センサー精度に及ぼすダイヤフラム寸法の影響(G03-2 材料力学(2)計測2,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

The role of a pressure sensor is to display pressure definitely for at least 2000 hours. However, a residual strain after reloading occurs in the diaphragm using in the high-pressure. This study involved a finite element analysis of the sensor. As the result of the analysis, the residual strain was improved by making the thickness of diaphragm thicker. However, it is thought that the sensitivity of a sensor may become poor. Therefore, it is important to reduce the force by optimizing the structure. Measurement accuracy and durability is required of high-pressure equipment. Therefore, it is important with the diaphragm type pressure sensor to examine the influence that shape and the size of diaphragm exert on the measurement accuracy and durability. As a first step, the diaphragm size was clarified. A finite element method (FEM) based on the experimental design was used. And, to optimize the size of the diaphragm, each part was examined by clarifying the stress and warp distributions.

ＦＢＧを用いた表面貼付型多点圧力センサの開発

An affix-type multipoint pressure sensor was developed by using the Fiber Bragg Grating (FBG) technology. The FBG technology is commonly used in optical communications and is being applied to the stress/strain measurement of a large structure recently. In this paper, the developed pressure sensor by use of FBG and the pressure measurement system are described. The FBG pressure sensor can be stuck on the surface of a body on which pressures will be measured, and is capable of the temperature compensation by using an FBG temperature sensor. The material and diameter of the diaphragm of the sensor and the pre-tension of the fiber were determined according to the pressure measurement test under static pressures. Pressure distributions on a circular cylinder in uniform flow were measured in a circular water channel, where pressures were also measured by a conventional strain-gauge type pressure sensor. Comparing the measured pressures, performances of the FBG pressure sensor are discussed.

Measurement of ski snow-pressure profiles

Bulge-disc type pressure sensors of diameter 6 mm were fitted as near as possible to the running edge of a modern carved ski. The pressure signals were sampled at 30 Hz during long turns on snow, synchronously with signals from a geomagnetic compass and a pressure pad in the ski boot. The pressure from the snow was found to be highly variable with a mean value of about 50 kPa and dynamic pressure spikes up to 300 kPa. With the outside leg, the snow contact width in the rear part of the ski was found to be slightly wider, on average, than for the front part, as expected for a carving turn. Correlation within the pressure sensor data showed that the rapid pressure fluctuations were probably not due to bumps or features on the snow; instead they were probably caused by many small-scale collapses of the snow structure as the ski passed.

ROMAP: Rosetta Magnetometer and Plasma Monitor

The scientific objectives, design and capabilities of the Rosetta Lander’s ROMAP instrument are presented. ROMAP’s main scientific goals are longterm magnetic field and plasma measurements of the surface of Comet 67P/Churyumov-Gerasimenko in order to study cometary activity as a function of heliocentric distance, and measurements during the Lander’s descent to investigate the structure of the comet’s remanent magnetisation. The ROMAP fluxgate magnetometer, electrostatic analyser and Faraday cup measure the magnetic field from 0 to 32 Hz, ions of up to 8000 keV and electrons of up to 4200 keV. Additional two types of pressure sensors – Penning and Minipirani – cover a pressure range from 10−8 to 101 mbar. ROMAP’s sensors and electronics are highly integrated, as required by a combined field/plasma instrument with less than 1 W power consumption and 1 kg mass.

Capacitive pressure sensors and switches fabricated using strain compensated SiGeB

The fabrication of capacitive pressure sensors and pressure switches using a 2.4 μm thick strain compensated heavily boron doped SiGeB diaphragm is presented. The process relies on the silicon fusion bonding of two silicon wafers to seal the pressure sensor cavity and construct the device. Both rectangular and circular type pressure sensors and pressure switches have successfully been fabricated using this process. Results are presented of a capacitive type sensor operating in the medical pressure regime (0–300 mmHg) with a sensitivity to pressure of 1.5 fF/mmHg or 305 ppm/mmHg, and of a pressure switch operating in the 3–8 bar pressure range and are thus suitable for a number of industrial and automotive applications. The current flowing through the switch when biased at 2 V jumps over six orders of magnitude when its two plates come in contact at a well defined pressure threshold.

수위, 온도, 전도도 측정을 위한 다기능 One-Chip 센서의 제조

The multi-functional one-chip sensor has been fabricated to reduce output variation under various water environment. There were a temperature sensor, a piezoresistive type pressure sensor, and a electrode type conductivity sensor in the fabricated one-chip sensor. This sensor was measured water depth in the range of <TEX>$0{\sim}180cm$</TEX>, temperature in the range of <TEX>$0{\sim}50^{\circ}C$</TEX>, and salinity in the range of 0 <TEX>$0wt%{\sim}5wt%$</TEX>, respectively. Since the change of water depth in solution environment depends on various factors such as salinity, latitude, temperature, and atmospheric pressure, the water depth sensor is needed to be compensated. We tried to compensate the salinity and temperature dependence for the pressure in water by using lookup-table method.

Performance and package effect of a novel piezoresistive pressure sensor fabricated by front-side etching technology

By applying the etching via technology, this study proposes a novel front-side etching fabrication process for a silicon-based piezoresistive pressure sensor to replace the conventional back-side bulk micro-machining. This novel structure pressure sensor can achieve the distinguishing features of the chip size reduction and fabrication costs degradation. In order to investigate the sensor performance and the sensor packaging effect of the structure proposed in this research, the finite element method was adopted for analyzing the sensitivity of the sensor signal. The signal sensitivity of the novel sensor after packaging was studied by applying mechanical as well as thermal loading to the sensor. Furthermore, the fabrication process and the sensor performance of the novel pressure sensor were compared with the conventional back-side etching type pressure sensor for the feasibility validation of the novel sensor. The results showed that the novel pressure sensor provides better sensitivity than that of the conventional one, and the sensor output signal variation due to package-induced thermal stress can be reduced by better packaging structure designs presented in this study. Based on the above findings, this novel structure pressure sensor shows a high potential for membrane type micro-sensor applications.

Contact pressure measurement using silicon-based Al xGa 1− xAs semiconductor pressure sensors

Various types of pressure sensors are widely used in manufacturing, defence, medical and precision industries. Most of these sensors are based on either piezoelectric or piezoresistive mechanism for sensing applications. Piezoelectric pressure sensors are not suited for measuring static pressure mainly due to leakage of electric charges under constant pressure. Surface micromachined silicon pressure sensors, based on piezoresistive mechanism, are reliable with satisfactory pressure sensitivity. However, the use of mechanical diaphragm limits the performance of the sensor due to its slow response time when a pressure is applied. The measurable pressure by silicon pressure sensor is also low (mostly in kPa range) and is not suitable for high contact pressure measurement (MPa in range). This paper reports the fabrication and testing of pressure sensitive silicon-based Al x Ga 1− x As pressure sensors, which are suitable for both static and dynamic pressure measurements with a wide range of applied pressure. The pressure sensors are fabricated based on two different kinds of substrates, silicon and GaAs, and tested under various conditions. Contact pressure sensitivity, linearity, hydrostatic pressure sensitivity, hysteresis, temperature sensitivity and long-time stability (creep) test results for these two types of the fabricated pressure sensors have been compared and presented in this paper.

High sensitivity in gas analysis with photoacoustic detection

Introduction of a new type of pressure sensor has been shown to improve orders of magnitude the sensitivity of a photoacoustic measurement system using a black body radiation source. A new pressure sensor was developed to overcome the limitations in the capacitive microphone technology and to obtain ultimate sensitivity in photoacoustic gas detection when using low modulation frequency below 500 Hz. The pressure sensor is a cantilever-type microphone with interferometric measurement of the sensor displacement. By using conventional filter-type photoacoustic setup with the cantilever microphone and a black body radiation source, we obtained a detection limit in the sub-ppb range for methane gas with 100 s measurement time.

고온용 세라믹 박막형 압력센서의 제작과 그 특성

This paper describes the fabrication and characteristics of ceramic thin film type pressure sensors based on Ta-N strain gauges for high temperature applications. Ta-N thin-film strain gauges are deposited onto a thermally oxidized Si diaphragm by RF sputtering in an argon-nitrogen atmos[here(<TEX>$N_2$</TEX> gas ratio: 8%, annealing condition: 90<TEX>$0^{\circ}C$</TEX>, 1 hr.), patterned on a wheatstone bridge configuration, and used as pressure sensing elements with a high stability and a high gauge factor. The sensitivity is 1.097 ～ 1.21 mV/Vㆍkgf/<TEX>$\textrm{cm}^2$</TEX> in the temperature range of 25 ～ 200 <TEX>$^{\circ}C$</TEX> and the maximum non-linearity resistance), non-linearity than existing Si piezoresistive pressure sensors. The fabricated ceramic thin-film type pressure sensor is expected to be usefully applied as pressure and load sensors that os operable under high-temperature.

Aligning anatomical structure from spiral X-ray computed tomography with plantar pressure data

Objective. To determine the reliability of identifying the location of each metatarsal head from spiral X-ray computed tomography on a matrix type pressure sensor recording. Design. Experimental; test–retest and within subject two-condition comparison. Background. Plantar pressure data quantify the amount of pressure and the general location of pressure. Specific anatomical structures associated with the site of pressure can only be determined by registering radiological data to the pressure sensor. Methods. Eighteen subjects, nine individuals without diabetes mellitus and nine individuals with diabetes mellitus, peripheral neuropathy, and a history of plantar foot ulcers, participated in plantar pressure testing and spiral X-ray computed tomography scanning of their foot. A registration technique was developed to align spiral X-ray computed tomography data with pressure sensor data. Results. When mapping the metatarsal head locations to the pressure sensor 48 of 90 metatarsal head locations were identical between repeated test occasions (53.3%), 40 of 90 metatarsal head locations were one pixel (5.08 mm) different between repeated test occasions (44.4%), and 2 of 90 were two pixels different (2.2%). Ninety-eight percent of repeated measures replicated exactly or varied by one pixel. Conclusion. Anatomical data from spiral X-ray computed tomography scanning can be reliably co-registered with pressure data. Relevance The ability to match bony anatomy to pressure data allows better understanding of structural factors contributing to peak pressure, provides precise information for three-dimensional modeling of the foot, and can improve orthotic fabrication and modification aimed at reducing pressure on the bottom of the foot.

B208 着座時における人体圧力分布測定システムの開発

Principal purpose of this study is to exploit a fully computerized monitoring system while a hospitalized patience is sleeping or moving on a bed without any personal privacy violation by measuring a dynamic pressure distribution. In order to develop a system, we have previously proposed a transformer type pressure sensor, which keeps cushiness as well as toughness to any types of pollution. This transformer type pressure sensor is composed of the spring coils as a primary coil, which keeps cushiness as a bed, and secondary coils to measure a pressure as an induced voltage.In the present paper, we have tried to develop a new dynamic pressure distribution sensor mat using magnetic fluid. As an initial test of our dynamic pressure-sensing mat, we have measured the static as well as quasi-dynamic pressure distributions when changing the sitting pose on a chair. To cognize the situation of sitting pose, we have applied the monochrome image cognition methodology. As a result, it is revealed that major sitting pose can be cognized. Thus, we have succeeded in an initial test of our fully computerized patience monitoring system without any violation of human privacy.

Reliability and validity of a multi-pad pressure evaluator for pressure ulcer management

It is often helpful to assess the pressures exerted upon the bony prominences when monitoring the likely outcome of pressure ulcer prevention or treatment. However, in the clinical setting, hard pressure sensors may damage the skin and operational difficulties may influence their reliability and validity. The authors have developed a multi-pad pressure sensor and tested its clinical reliability and validity. The inter-rater and intra-rater reliability were calculated using the coefficient of variation data from 10 patients. After a comparison analysis, the multi-pad was more reliable than a single-pad type pressure sensor. A validation test was conducted in 79 elderly patients. The mean interface pressures recorded among patients who had erythema or stage I pressure ulcers at the sacrum were significantly higher than were the contact pressures measured in patients with no pressure damage. The pressure sensor exhibited satisfactory clinical reliability and validity. Furthermore, it may be that for Japanese elderly patients the maximum pressure that can be tolerated by the tissues around the sacrum may be 40-50 mmHg.

스테인레스 봉입형 반도체 압력센서의 제작 및 그 특성

스테인레스 봉입형 압력센서를 제작하기 위하여 먼저 반도체 제조 및 식각 공정을 통하여 반도체 압력센서를 제작하였다 그리고 이를 glass molding된 스테인레스 housing에 올려놓고 <TEX>$50\;{\mu}m$</TEX> 두께의 스테인레스 박판을 용접한 후 실리콘 오일을 채워 넣고 봉입하여 압력 범위 10 bar 센서를 완성하였다. 이와 같이 제작한 센서와 XTR105 발신기 전용 회로를 결합하여 <TEX>$4{\sim}20\;mA$</TEX> 출력의 압력 발신기를 제작하고 그 특성을 조사하였다. 온도 보상 전 정확도는 <TEX>${\pm}5%$</TEX> FS이었으나 보상 후 정확도 <TEX>${\pm}1%$</TEX> FS로 개선되었다. The silicon piezoresistive pressure sensor is made by semiconductor process to obtain stainless steel isolated type pressure sensor. The sensor is loaded on a stainless steel housing with glass molding, <TEX>$50\;{\mu}m$</TEX> stainless steel thin film is welded, and the stainless steel housing encapsulated by silicone oil. The performance of fabricated the pressure sensor has 10 bar pressure range. The XTR105 of exclusive transmitter chip is used the pressure transmitter that output current is 4 - 20 mA. The accuracy is <TEX>${\pm}5%$</TEX> FS, however, the accuracy is <TEX>${\pm}1%$</TEX> FS when the sensor is compensated temperature.

Overview of automotive sensors

An up-to-date review paper on automotive sensors is presented. Attention is focused on sensors used in production automotive systems. The primary sensor technologies in use today are reviewed and are classified according to their three major areas of automotive systems application-powertrain, chassis, and body. This subject is extensive. As described in this paper, for use in automotive systems, there are six types of rotational motion sensors, four types of pressure sensors, five types of position sensors, and three types of temperature sensors. Additionally, two types of mass air flow sensors, five types of exhaust gas oxygen sensors, one type of engine knock sensor, four types of linear acceleration sensors, four types of angular-rate sensors, four types of occupant comfort/convenience sensors, two types of near-distance obstacle detection sensors, four types of far-distance obstacle detection sensors, and and ten types of emerging, state-of the-art, sensor technologies are identified.

Development of a new pressure sensor and its application to the measurement of contacting stress in extrusion

A new type of pressure sensor with no annular gap and no level difference in the tool surface has been developed. The principal structure of the sensor is the combination of an inner shaft and an outer tube connected at the tool surface and combined with a common beam at the other end. The sensor is available for various plastic deformation processes under different friction conditions. As one application of this sensor, the container pressure distribution in various extrusions such as forward extrusion, backward extrusion and pierce extrusion have been measured. The characteristic of the pressure distribution in each extrusion process has been made clear.

カバリングマシンの自動糸交換装置の開発 第４報 圧力変化を利用した芯糸検出装置

Drawing-in process on covering machines is so difficult and inefficient that its automation is especially hoped. However the automatic drawing-in system developed in order to improve drawing-in operation is not able to distinguish whether the core yarn is successfully drawn into the hollow spindle or not. So we developed a detecting system for fine Spandex, applying pressure variation in pipe flow caused by yarn behavior.Results obtained are as follows : (1) Pressure variation can check the presence of Spandex when it runs through, a small air flow pipe. (2) This detecting system consists of a diaphragm type pressure sensor, a small pipe and a simple sequence program. (3) The system can detect Spandex yarns from 30D to 420D that are widely used and too thin to sense even by manual operation. And it is confirmed that the system has practical utility. (4) The system is installed on the automatic yarn drawing-in device. When the system distinguish the failure to draw Spandex into hollow spindles, the failed Spandex package is removed and drawing-in is again attempted with another package on the same spindle. In this way, yarn drawing-in is performed for all spindles on a covering machine continually and automatically.