• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.4
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• pp.491-499
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• 2009

The determination of response characteristics for pressure sensors is routinely limited to static calibration against a deadweight pressure standard. The strength of this method is that the deadweight device is a primary standard used to generate precise pressure. Its weakness lies in the assumption that the static and dynamic responses of the sensor in question are equivalent. Differences in sensor response to static and dynamic events, however, can lead to serious measurement errors. Dynamic techniques are required to calibrate pressure sensors measuring dynamic events in milliseconds. In this paper, a dynamic calibration using negative going dynamic pressure is proposed to determine dynamic pressure response for piezoelectric sensors. Sensitivity and linearity of sensor by the dynamic calibration were compared with those by the static calibration. The uncertainty of calibration results and the goodness of fit test of linear regression analysis were presented. The results show that the dynamic calibration is applicable to determine dynamic pressure response for piezoelectric sensors.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.17-21
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• 2012

This study developed a high-temperature, high-pressure dynamic pressure sensor using LGT(lanthanum gallium tantalate). The sensitivity of the fabricated dynamic pressure sensor was 2.1 mV/kPa and its nonlinearity was 2.5%FS. We confirmed that the high-temperature dynamic pressure sensor operated stably in high-temperature environment at $500^{\circ}C$. The developed dynamic pressure sensor using LGT is expected to be applicable not only to gas turbines but also in various industrial areas in duding airplanes and power stations.

• Physical Therapy Korea
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• v.8 no.3
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• pp.1-10
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• 2001

The purpose of this study was to compare the static pressure, dynamic pressure, dynamic pressure-time integral, relative impulse, and contact time between the sound lower limb and amputated lower limb in trans-tibial amputee subjects using Parotec system. Seventeen trans-tibial amputee subjects wearing endoskeletal trans-tibial prosthesis voluntarily participated in this study. The results were as follows: 1) In static standing condition, there were significantly higher static pressure in sound lower limb insole sensor of 10, 14, 15, 18, 19, 23, and 24 and in amputated lower limb insole sensor of 9, 12, and 16 (p<.05). 2) In dynamic gait condition, there were significantly higher dynamic pressure in sound lower limb insole sensor of 2, 18, 22, 23, and 24 and in amputated lower limb insole sensor of 5, 9, 10, 11, 12, 14, 15, and 16 (p<.05). 3) In dynamic gait condition, there were significantly higher pressure-time integral in sound lower limb insole sensor of 2, 4, 18, 19, 20, 21, 23, and 24 and in amputated lower limb insole sensor of 5, 11, 12, and 15 (p<.05). 4) In dynamic gait condition, there were significantly higher relative impulse in sound lower limb insole sensor of 18, 19, 20, 22, 23, and 24 and in amputated lower limb insole sensor of 5, 9, 10, 11, 12, and 15 (p<.05). 5) In dynamic gait condition, there was significantly higher percentage of contact time in push off phase of sound lower limb and in support phase of amputated lower limb (p<.05). These results suggest that trans-tibial amputee subjects had characteristics of shortened push off phase due to unutilized forefoot and of lengthened support phase with higher pressure in the midfoot.

• Explosives and Blasting
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• v.38 no.1
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• pp.23-29
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• 2020

The measurement technique with dynamic shock sensor was widely used in academic experiment for blasting and impact. However, most of dynamic sensors are expensive so that it needs to be protected by external housing structures or damping devices. In this study, the calibration method for dynamic shock sensor under the distortion by external structures. Hopkinson pressure bar system was adopted to measure the input acceleration to the sensor, and it was compared to the acceleration measured by accelerometer with customized damping device. Consequently, it is conclued that this method can be useful to calibrate the dynamic shock sensor under the linear distortion.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.2
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• pp.83-93
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• 2020

Dynamic pressure transducer needs to be flush-mounted on hardware due to frequency response characteristics of pressure transmission system. However, it is sometimes necessary to be mounted in recessed configuration due to insufficient space for sensor installation and for protection of sensor from thermal damage. Dynamic response characteristics should be considered due to distortion of original dynamic pressure signal in the pressure transmission system. In this study, small perturbation model and 2nd order reduced model were compared with experiments and a guideline for selecting a frequency response model was suggested.

• Advances in aircraft and spacecraft science
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• v.6 no.6
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• pp.497-513
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• 2019

A wind tunnel test was conducted that measured surface fluctuating pressures aft of a ramp at transonic speeds. Dynamic pressure test data was used to perform a study to determine best locations for streamwise sensor pairs for shocked and unshocked runs based on minimizing the error in root-mean-square acceleration response of the panel. For unshocked conditions, the upstream sensor is best placed at least 6.5 ramp heights downstream of the ramp, and the downstream sensor should be within 2 ramp heights from the upstream sensor. For shocked conditions, the upstream sensor should be between 1 and 7 ramp heights downstream of the shock, with the downstream sensor 2 to 3 ramp heights of the upstream sensor. The shock was found to prevent the passage coherent flow structures; therefore, it may be desired to use the shock to define the boundary of subzones for the purpose of loads definition. These recommendations should be generally applicable to a range of expansion corner geometries in transonic flow provided similar flow structures exist. The recommendations for shocked runs is more limited, relying on data from a single dataset with the shock located near the forward end of the region of interest.

• Journal of Sensor Science and Technology
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• v.22 no.3
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• pp.227-232
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• 2013

In this research, fiber-optic pressure sensors were fabricated with rugate-structured porous silicon (RPS) diaphragms coated with PMMA (Polymethyl-Methacrylate). The reflectance spectrum of the PMMA/RPS diaphragm was almost the same as that of uncoated RPS diaphragm. However the mechanical strength of the PMMA/RPS diaphragm increased more than that of the uncoated diaphragm. As a result, the fiber-optic sensor fabricated with PMMA/RPS diaphragm could successfully detect more high pressure difference without diaphragm damage than the highest detectable pressure difference of the sensor with normal RPS diaphragm. The response data of the fiber-optic sensor recorded as a function of pressure difference were fitted by theoretical curves. During this process, elastic moduli of the used PMMA/RPS diaphragms were obtained numerically. The dynamic response properties of the fiber-optic sensor were also investigated under continuous variation of the pressure difference conditions.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.9
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• pp.2381-2389
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• 1993

In this paper the design and test results of a dynamic flow rate sensor was reported. This sensor comprises an 2-way cartridge valve as standard hydraulic component and a displacement sensor. Its working principle bases on the linear relationship between the flow rate and the piston displacement of 2-way cartridge valves under constant pressure drop. This principle is well known, however it is not easy to develop a flow rate sensor with the measurement range of 300 1/min, pressure loss of less than 8 bar at 300 1/min, maximum linearity error of less than $\pm$1% and the maximum rising time of 10 ms. This paper describes the design procedure of the flow rate sensor, the improvement procedure of static performance and test method and results of dynamic performance.

• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.251-261
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• 2006

The objective of this work is to apply artificial neural networks for solving inverse problems in the structural optimization of a fiber optic pressure sensor. For the sensor under investigation to achieve a desired accuracy, the change in the distance between the tips of the two fibers due to the applied pressure should not interfere with the phase change due to the change in the density of the air between the two fibers. Therefore, accurate dynamic analysis and structural optimization of the sensor is essential to ensure the accuracy of the measurements provided by the sensor. To this end, a normal mode analysis and a transient response analysis of the sensor were performed by combining commercial finite element analysis package, MSC/NASTRAN, and MATLAB. Furthermore, a parametric study on the design of the sensor was performed to minimize the size of the sensor while fulfilling a number of constraints. In performing the parametric study, the need for a relationship between the design parameters and the response of the sensor was fulfilled by using a neural network. The whole process of the dynamic analysis using commercial finite element analysis package and the parameter optimization of the sensor were automated within the MATLAB environment.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.328-331
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• 1998

Because of the powerful tolerance of overload, dynamic response and anti-erosion, Reluctive Pressure Transducer(RPT), as a measuring element of oil pressure equipment is applied to the measuring system of vessels, air craft. The Electrical reluctance appeared in the pressed diaphragm. To process the reluctance as a electric signal, bridge circuit is used. The design using the reluctance of pressure sensor is described in this paper. For the high efficiency of the sensitive RPT, pressure sensor structure is presented and electrical signal processing is simulated.