• Title/Summary/Keyword: measurement of Pressure

Search Result 3,209, Processing Time 0.032 seconds

Measurement of Unsteady Total Pressure downstream of an 1-Stage Axial Turbine (1단 축류터빈 로터의 후류에서 비정상 전압력 측정에 관한 연구)

  • Kang, Jeong-Seek;Cha, Bong-Jun;Yang, Soo-Seok;Lee, Dae-Sung
    • 유체기계공업학회:학술대회논문집
    • /
    • 2005.12a
    • /
    • pp.318-323
    • /
    • 2005
  • To evaluate the accurate performance of turbomachinery, it is important to measure the unsteady flow phenomena downstream of the rotor blade. This paper presents the development of the fast-response total pressure probe for the measurement of the total pressure field at the exit of rotor and the result of measurement in a 1-stage axial turbine. The fast-response total pressure probe was fabricated by installing a fast-response pressure sensor near the head of a Kiel probe. And it measured the phase-lock averaged total pressure downstream of an 1-stage axial turbine. The developed probe successfully measured the accurate total pressure distribution at rotor exit and made possible to evaluate the loss distribution and the accurate performance of turbomachinery.

  • PDF

Verification of Reliable Blood Pressure Monitor in a Moving Ambulance during an Emergency (응급상황시 이송중인 구급차에서 신뢰할 수 있는 혈압계 검증)

  • Jeon, Jai-In
    • The Journal of the Convergence on Culture Technology
    • /
    • v.8 no.3
    • /
    • pp.91-97
    • /
    • 2022
  • The purpose of this study was to analyze the measurements of blood pressure and time using manual and automatic blood pressure monitors in various road conditions to verify reliable blood pressure monitor in a moving ambulance. First, the manual blood pressure monitor palpation on unpaved roads showed a systolic pressure deviation of 5 mmHg. However, the automatic blood pressure monitor showed two measurement failures, one reading failure, and the measured systolic pressure deviation was 35 mmHg. The measurement time was 102 seconds faster on average than the automatic blood pressure monitor. Second, the palpation of the manual blood pressure monitor while going over speed bumps remained constant at 130 mmHg. However, the automatic blood pressure monitor had a systolic pressure deviation of 52 mmHg. The measurement time was 61 seconds faster on average than the automatic blood pressure monitor. Finally, the manual blood pressure monitor palpation on the sharp curve road showed a systolic pressure deviation of 5 mmHg. The automatic blood pressure monitor had one reading failure and the measured systolic pressure deviation was 21 mmHg. The measurement time showed that the manual blood pressure monitor was 101 seconds faster than the automatic blood pressure monitor. As a result, in a moving ambulance during an emergency, the manual blood pressure monitor showed high reliability because the blood pressure measurement was constant and the measurement time was short.

A Comparative Study of Blood Pressure According to Cuff Size and Measurement Site (커프크기와 측정부위에 따른 혈압측정치 비교 연구)

  • Song, Mi-Ryeong;Kim, Eun-Kyung
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.16 no.1
    • /
    • pp.6-13
    • /
    • 2009
  • Purpose: The purpose of this study was to identify differences in blood pressure according to cuff size and measurement sites of the participants. Method: The participants consisted of 50 women and 50 men whose upper arm circumference was $26\sim30cm$. They had no chronic illness and gave consent to participate. Blood pressure of the wrist was measured in the sitting position, the upper arm with a standard cuff, large and small cuffs were used for measurement in supine position and the thigh in prone position. The data were analyzed with paired t-test using SPSS 12.0 program. Result: The data for the upper arm showed a difference in systolic and diastolic blood pressure depending on the site of measurement. There was a significant difference between measurements with a standard cuff and measurements with large and small cuffs. The systolic blood pressure of the wrist and the thigh were significantly lower than that of the upper arm. Conclusion: These results suggest that the selection of an appropriate cuff is an essential element in ensuring accuracy when measuring blood pressure and differences in systolic blood pressure for the upper arm, wrist and thigh indicate the need to record the measuring site when measuring blood pressure.

  • PDF

Study of Digital Air Meter Used Pressure Sensor for Air Content of Freshly Mixed Concretes (압력센서를 이용한 디지털 콘크리트 공기량 시험기 개발에 관한 연구)

  • Yoon, In-Jun;Lee, Kyoung-Moon;Seo, In-Ho
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2006.05a
    • /
    • pp.566-569
    • /
    • 2006
  • The purpose of this study is to develop digital air meter used pressure sensor for measurement of air content in freshly mixed concrete by pressure method. The digital air meter can enhanced measurement accuracy and uniformity of air content in freshly concretes, according to use of pressure sensor and measuring process automation. Finally, the digital air meter in this study is improved reproducibility and reliability of measurement compared with analog air meter.

  • PDF

Review on Floating Pulse and Sinking Pulse in the View Point of Tonometric Measurement (토노메트리 측정 관점에서의 부침맥 고찰)

  • Lee, Jeon;Lee, Yu-Jung;Ryu, Hyun-Hee;Lee, Hae-Jung;Kim, Jong-Yeol
    • Korean Journal of Oriental Medicine
    • /
    • v.14 no.2
    • /
    • pp.113-119
    • /
    • 2008
  • In pulse diagnosis, floating pulse and sinking pulse are frequently used for diagnosis about where disease is located and how much severe they are. However, in what mechanism floating pulse and sinking pulse arise is not known well. There are two point of views on substantial of floating pulse and sinking pulse. The first one is the floating and sinking degrees is the expression on the depth of pulsation. And, the second one is floating and sinking pulse is based on the response of pulsation to the indent pressure on radial artery. In this paper, we discussed these two opinions in the view point of tonometric measurement. The process for diagnosis on floating pulse and sinking pulse is similar to the tonometric measurement for non invasive blood pressure or intraocular pressure. We modelled the degrees of depth of pulsation with different indent pressures for initial pulsation feeling and different slopes of indent pressure lines. From this modelling, we can confirm the effect of pulsation depth on P-H curve, that is, in the model where lower pulsation is assumed, the shift of optimal indent pressure to the right was observed. The response of pulse pressure to the indent pressure was tried to be modelled with the degrees of mean blood pressure. Consequently, we tried to model the phenomenon of floating and sinking pulse for the first. And, from this modelling, we can get abundant understanding on how floating and sinking pulse can be caused. In the further study, we want to prove the suitability of this tonometric measurement based modelling with various studies including ultrasound measurement for the depth of pulsation in different EMI subjects.

  • PDF

Analysis and Measurement of the Nip Pressure of Roll Cleaner (롤 크리너 선압의 해석 및 측정기술)

  • Choi Hyeon-Cheol;Lee Eung-Ki;Choi Jong-Guen
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.30 no.10 s.253
    • /
    • pp.1328-1334
    • /
    • 2006
  • In the rolling mills for sheet metal rolling, paper rolling and etc., the impurities of roller surface have crucial effects on the surface quality of the products obtained by rolling. The Roll Cleaner is a device to remove impurities on roller surface during a rolling operation. Nip Pressure means the line pressure interacted between the roll cleaner blade and the roller surface. The nip pressure is the most important parameter which decides the performance of roll cleaner, and it depends upon several factors including the cleaner design and its blade stiffness. This study, first, analyzes the mechanism of the nip pressure generation for a roll cleaner designed commercially, which is an crucial process for effective design of roll cleaners. Second, the technique for the measurement of nip pressure is developed, which is useful to verify the performance of roll cleaners and to setup them properly at factory floor.

The study on the measurement for the pressure drop and friction factor of corrugated metal pipes (주름관에서의 압력강하와 마찰손실 계측에 관한 연구)

  • Yun, Young-Sun;Kang, Jun-One;Yoo, Jai-Suk;Kim, Hyung-Jung
    • Journal of the Korean Society of Visualization
    • /
    • v.4 no.2
    • /
    • pp.76-80
    • /
    • 2006
  • The data for friction factor of the pipe correlated by Reynolds number and relative roughness have been reported well as a Moody chart. However, the results for corrugated shapes have been not investigated sufficiently. In this research, therefore, the pressure drop and friction factor are obtained. Flexible metal tubes with corrugations for the measurement are made of stainless steel plates. The kinds of tubes for the measurement are 5 annular types and helical types. The pressure drop & the velocity of the flow are obtained by micromanometer & digital pressure sensor, supplying dry air at several steps. Then the pressure drop is calculated for each tube, using the obtained data. The result shows that the pressure drop is strongly influenced by the viscous dissipation of kinetic energy due to the circulation of flows, rather than a viscous friction loss. The pressure drop increased consistently as the Reynolds number increases.

  • PDF

A Study on the Measurement of Oil-Film Pressure in Engine Connecting Rod Bearing and Piston Pin-Boss by Thin-Film Sensor

  • Mihara, Yuji;Someya, Tsuneo
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2002.10b
    • /
    • pp.409-410
    • /
    • 2002
  • In order to measure the oil-film pressure in sliding surface of machinery, we have developed a piezo-resistive type thin-film pressure sensor. To reduce the measurement error due to temperature and strain, the constituent of the pressure sensitive alloy was optimized and a new sensor shape was devised. In this study, we present the measurement results of the oil-film pressure distribution in engine connecting rod big-end bearing and piston pin- bosses with 3 different pin-boss shapes using the newly developed thin-film pressure sensor.

  • PDF

Data processing of sensor output for correction of pressure measurement value of an anesthesia ventilator (마취기용 인공호흡기의 압력 측정값의 보정을 위한 센서 출력의 데이터 처리)

  • 박영준;이종수;김영길
    • Proceedings of the IEEK Conference
    • /
    • 1999.11a
    • /
    • pp.1067-1070
    • /
    • 1999
  • Anesthesia gas to pour to patients affects the flow and volume as the pressure difference of an oxygen and an anesthesia gas. An anesthesia gas, being injurious and polluting an environment, must control the pressure of an oxygen gas because of being used by closing up tight. But a pressure sensor to use for measuring an oxygen gas appears other pressure as the characteristic and the error difference of elements to use for implementing an system. A medical machine such as an anesthesia ventilator must be accurate because of using for the person's body. So we intend to implement an system for a sensor pressure measurement not to be change regardless of an environment. This papers is the target that a sensor pressrue measurement to be changed in environment is equal to actual sensor pressure measurement. So an implemented system is using analog filter and digital filter to reduce a noise. And we are using auto-zeroing and calibration to correct a sensor pressure which is changed in environment. Through such a process we increase the accuracy and the confidence of an anesthesia ventilator by controlling the flow of an anesthesia gas.

  • PDF

Field measurement and CFD simulation of wind pressures on rectangular attic

  • Peng, Yongbo;Zhao, Weijie;Ai, Xiaoqiu
    • Wind and Structures
    • /
    • v.29 no.6
    • /
    • pp.471-488
    • /
    • 2019
  • Wind pressure is a critical argument for the wind-resistant design of structures. The attempt, however, to explore the wind pressure field on buildings still encounters challenges though a large body of researches utilizing wind tunnel tests and wind field simulations were carried out, due to the difficulty in logical treatments on the scale effect and the modeling error. The full-scale measurement has not yet received sufficient attention. By performing a field measurement, the present paper systematically addresses wind pressures on the rectangular attic of a double-tower building. The spatial and temporal correlations among wind speed and wind pressures at measured points are discussed. In order to better understand the wind pressure distribution on the attic facades and its relationship against the approaching flow, a full-scale CFD simulation on the similar rectangular attic is conducted as well. Comparative studies between wind pressure coefficients and those provided in wind-load codes are carried out. It is revealed that in the case of wind attack angle being zero, the wind pressure coefficient of the cross-wind facades exposes remarkable variations along both horizontal and vertical directions; while the wind pressure coefficient of the windward facade remains stable along horizontal direction but exposes remarkable variations along vertical direction. The pattern of wind pressure coefficients, however, is not properly described in the existing wind-load codes.