Pressure sensor based tsunami detection system: A laboratory study

In this paper, we present the study and implementation of a low-cost system to detect the occurrences of tsunamis at significantly smaller laboratory scale. The implementation is easily scalable for real-time deployment. Information reported in this paper includes the experimentally recorded response from the pressure sensor giving an indication as well as an alarm at remote place for the detection of water turbulence similar to the case of tsunami. It has been found that the system developed works very well in the laboratory scale.

MEMS based pressure sensor with triple modular redundancy

In this paper, the design and development of micro electro mechanical systems (MEMS) based pressure sensor with triple modular redundancy (TMR) for space applications has been presented. In order to minimize the mass of the system and also to avoid the uncertainty in the pressure measurement of the three independent hardware, an integrated approach with TMR is adopted. Sequential steps of TMR logic followed and the test results obtained are included.

Peristaltic pump-based low range pressure sensor calibration system

Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory. (C) 2015 AIP Publishing LLC.

Film bulk acoustic resonator pressure sensor with self temperature reference

A novel film bulk acoustic resonator (FBAR) with two resonant frequencies which have opposite reactions to temperature changes has been designed. The two resonant modes respond differently to changes in temperature and pressure, with the frequency shift being linearly correlated with temperature and pressure changes. By utilizing the FBAR's sealed back trench as a cavity, an on-chip single FBAR sensor suitable for measuring pressure and temperature simultaneously is proposed and demonstrated. The experimental results show that the pressure coefficient of frequency for the lower frequency peak of the FBAR sensors is approximately -17.4 ppm kPa-1, while that for the second peak is approximately -6.1 ppm kPa-1, both of them being much more sensitive than other existing pressure sensors. This dual mode on-chip pressure sensor is simple in structure and operation, can be fabricated at very low cost, and yet requires no specific package, therefore has great potential for applications. © 2012 IOP Publishing Ltd.

SOI membrane-based pressure sensor in stress sensitive differential amplifier configuration

This paper introduces a pressure sensing structure configured as a stress sensitive differential amplifier (SSDA), built on a Silicon-on-Insulator (SOI) membrane. Theoretical calculation show the significant increase in sensitivity which is expected from the pressure sensors in SSDA configuration compared to the traditional Wheatstone bridge circuit. Preliminary experimental measurements, performed on individual transistors placed on the membrane, exhibit state-the-art sensitivity values (1.45mV/mbar). © 2012 IEEE.

Fiber Bragg grating pressure sensor with enhanced sensitivity

A novel fiber Bragg grating (FBG) pressure sensor with the enhanced sensitivity has been demonstrated. A piston-like diaphragm with a hard core in the center is used to enhance the sensitivity. Both the theoretical analysis and the experimental result show that the radius of the hard core has significant effect on the pressure sensitivity. When the radius of the hard core is 1.5 mm, a pressure sensitivity of 7.23 nm/MPa has been achieved.

MEMBRANE-BASED FIBER BRAGG GRATING PRESSURE SENSOR WITH HIGH SENSITIVITY

A fiber Bragg grating (FBG) pressure sensor packaged by using a hard core in the membrane is presented. By utilizing the unique membrane-based FBG packagine method, its pressure sensitivity has been effectively enhanced. The pressure sensitivity of the FBG reaches 5.75 X 10(-3)/MPa within the pressure range of 0.0.16 Mpa. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51 1279-1281, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24335

Fiber Bragg grating pressure sensor with ultrahigh sensitivity and reduced temperature sensitivity

A fiber Bragg grating (FBG) pressure sensing scheme based on a flat diaphragm and an L-shaped lever is presented. An L-shaped lever transfers the pressure-induced defection of the flat diaphragm to the axial elongation of the FBG. The curve where the L-shaped lever contacts the diaphragm is a segment of an Archimedes spiral, which is used to enhance the responsivity. Because the thermal expansion coefficient of the quartz-glass L-shaped lever and the steel sensor shell is different, the temperature effect is compensated for by optimizing the dimension parameters. Theoretical analysis is presented, and the experimental results show that an ultrahigh pressure responsivity of 244 pm/kPa and a low temperature responsivity of 2.8 pm/degrees C are achieved. (c) 2009 Society of Photo-Optical Instrumentation Engineers. [DOI 10.1117/1.3081058]

FBG pressure sensor based on the double shell cylinder with temperature compensation

A novel fiber Bragg grating (FBG) pressure sensor based on the double shell cylinder with temperature compensation is presented. in the sensing scheme, a sensing FBG is affixed in the tangential direction on the outer surface of the inner cylinder, and another FBG is affixed in the axial direction to compensate the temperature fluctuation. Based on the theory of elasticity, the theoretical analysis of the strain distribution of the sensing shell is presented. Experiments are carried out to test the performance of the sensor. A pressure sensitivity of 0.0937 nm/MPa has been achieved. The experimental results also demonstrate that the two FBGs have the same temperature sensitivity, which can be utilized to compensate the temperature induced wavelength shift during the pressure measurement. (C) 2008 Elsevier Ltd. All rights reserved.

Ultrathin FBG pressure sensor with enhanced responsivity

An ultrathin fiber Bragg grating pressure sensor with enhanced sensitivity is demonstrated. A novel piston-like diaphragm with a hard core in the center is used as the sensing element to enhance the responsivity. Both the theoretical analysis and the experimental results show that the Young's modulus of the diaphragm and the radius of the hard core have significant effect on the pressure responsivity. By optimizing these two parameters, a pressure responsivity of 7 nm/MPa has been achieved.

Temperature-independent FBG pressure sensor with high sensitivity

This study develops a fiber Bragg grating (FBG) pressure sensor partly shielded with a metal tube. The thermal-strain cross effect is avoided and its pressure sensitivity is increased to -2.44 x 10(-3) MPa, about 1200 times as that of a bare fiber grating. Due to its good sensing linearity, this sensor can be applied in the measurement of hydraulic pressure and vibration. (c) 2006 Elsevier Inc. All rights reserved.