• Title/Summary/Keyword: Manometer

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Study on Reillumination of Hi-soo type Electronic Manometer (희수식 전자 맥진기의 재조명)

  • Kim, Eun-Hye;Kim, Byung-Soo;Kang, Jung-Soo
    • Journal of Haehwa Medicine
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    • v.18 no.2
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    • pp.37-45
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    • 2009
  • In early 1970s, Electronic Manometers were researched and developed for modernization and objectification of pulse diagnosis. Method of finger pressing, also known as cuffs pressing, is essential for sensing a pulse wave. I think comprehension and deduction of problem from the existing Hi-soo type electronic manometer, will be important for making a better one. The Hi-soo type electronic manometer is constructed of cuff pressing type sensor, differential amplifier, transmitter and recorder. Pulse movement and pulse wave, gauging blood flow, is analyzed by pulse image of "Yixuerumen(醫學入門)". At standard of pulse wave, huanmai(緩脈) is distinguish from chishu(slow and fast, 遲數), fushen(float and sink, 浮沈), interference wave, modificated wave, and phase angel. The Hi-soo type electronic manometer had no explanation of formational mechanism, significantly different with pulse wave which is early known and reported. The strength of Hi-soo type electric manometer is use of cuff pressing type sensor. Above all, the importance of electric manometer is reading the pulse movement accurately then expressing it as pulse wave. From now on the improvement of precise sensor should make a progress.

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A study on medium-low pressure gauge for domestic production (중.저기압 압력계의 국산화에 관한 연구)

  • 백용현
    • 전기의세계
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    • v.29 no.8
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    • pp.519-523
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    • 1980
  • The traditional mechanical manometer is improved to develop more convenient and precise manometer in continuous measurement of the gas pressure in medium-low vacuum range (1x10$^{-1}$ -10 Torr.) Glass (solid) is used as a detector material of the improved manometer. Using the strain gauge adhered to thin glass board, mechanical strain corresponding to variation of pressure in measurement system is converted into quantity of electricity, and the quantity of electricity is amplified. Experiments have also shown that the improved manometer have more advantages in reproducibility, measured sensibility, and responsible velocity than taditional one.

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Development of Uncertainty Evaluation Model for Vacuum Measurement Standards (진공측정표준의 불확도 평가모델 개발)

  • Hong, S.S.;Lim, J.Y.;Shin, Y.H.
    • Journal of the Korean Vacuum Society
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    • v.20 no.5
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    • pp.313-321
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    • 2011
  • The Korea Research Institute of Standards and Science (KRISS) has three major vacuum systems: an ultrasonic interferometer manometer (UIM), a static volume expansion system (SVES), and an orifice-type dynamic expansion system (ODES). For each system explict measurement model equations with multiple variables are respectively given. According to ISO standards, all these system variables errors were used to calculate the expanded uncertainty (U).

Measurement Uncertainties for Vacuum Standards from a Low to an Ultra-high Vacuum

  • Hong, S.S.;Shin, Y.H.;Lim, J.Y.
    • Applied Science and Convergence Technology
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    • v.23 no.3
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    • pp.103-112
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    • 2014
  • The Korea Research Institute of Standards and Science (KRISS) has three major vacuum systems: an ultrasonic interferometer manometer (UIM; Section II, Figs. 1 and 2) for a low vacuum, a static expansion system (SES; Section III, Figs. 3 and 4) for a medium vacuum, and an orifice-type dynamic expansion system (DES, Section IV, Figs. 5 and 6) for high and ultra-high vacuum systems. For each system, explicit measurement model equations with multiple variables are given. According to ISO standards, all of these system variable errors were used to calculate the expanded uncertainty (U). For each system, the expanded uncertainties (k = 1, confidence level = 95%) and relative expanded uncertainty (expanded uncertainty/generated pressure) levels are summarized in Table 4. Within the uncertainty limits, our bilateral and key comparisons [CCM.P-K4 (10 Pa to 1 kPa)] are extensive and in good agreement with those of other nations (Fig. 8 and Table 5).

A Review on the Performance Criteria of Equipment Required for Asbestos Removal (석면 해체.제거 작업에서 사용되는 장비의 성능 기준에 관한 고찰)

  • Lee, Naroo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.3
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    • pp.212-221
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    • 2013
  • Objectives: Asbestos fibers are accumulated in negative pressure unit (NPU) or vacuum cleaner in asbestos removal. Failure of operation or poor use performance of the NPU or vacuum cleaner causes asbestos fibers to spread in the air. Asbestos contractors should have an NPU fitted with a HEPA , vacuum cleaner, decontamination area, respirators, wetting equipment, and differential pressure manometer to register with the Ministry of Employment and Labor. There should be performance criteria of equipment used in asbestos removal. But there are none such criteria used in asbestos removal. This study was performed to investigate international or national performance criteria of equipment used in asbestos removal. Methods: Regulations, approved code of practice, guidance and national standards of the UK, USA and Korea were reviewed. A survey was done to investigate the requirements for equipment used in asbestos removal in Korea. Results: Air flow of NPUs used in Korea usually covers from$500m^3/h$ to over $3000m^3/h$. Some requirements for NPUs used in Korea were missing compared to the requirements of British standards for NPUs. All NPUs have different missing requirements. The UK also has separate British standard for leak tests for NPUs. Highly hazardous class vacuum cleaners should be used in asbestos removal in the UK. It has national standards on the operation of vacuum cleaners used in asbestos removal. There is only a certification system for less than 2.5kw rated voltage vacuum cleaners for home use in Korea. Powered (-assisted) respirators with mask are recommended in asbestos removal. Type 5 coveralls should be used in asbestos removal in the UK. There are international standards for requirements and leak tests of type 5 coveralls. A manometer for measuring differential pressure is needed in asbestos removal. The manometer's measuring range should cover less than ${\pm}125$ Pa and the gradation of manometer should be less than 2.5 Pa. The definition of decontamination area should be corrected. Installation of airlock and minimum area should be considered in decontamination area. Conclusions: Equipment should be used in asbestos removal proper performance and no leaks. There should be a certification system for equipment used in asbestos removal. This study can help to a certification system for equipment used in asbestos removal in Korea.

An Experimental Study of the Flow Characteristics around 2D Multi-Cylinders ( I ) (2차원 다원주 주위의 유동 특성에 관한 실험적 연구 ( I ))

  • 김두홍;조철희;정우철;박찬원;나인삼
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.10a
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    • pp.190-195
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    • 2001
  • Flow patterns are very complex and interactive between cylinders. The patterns are turbulent and non-linear caused by various factors. In this paper, flow patterns and pressure gradient around vertical cylinders were investigated by experiment. Changing gaps between cylinders the flow patterns are measured at a fixed coming velocity. Flow patterns showed very complex and closely related to the coming velocity and cylinder space. The pressure gradient around the flow field is observed by twelve hole pitot tubes and manometer. The experiment has been conducted in circulating water channel with PIV system. That can visualize flow patterns. The laser beam was used to reflect the image from particles and recorded by CCD camera. The cylinders were spaced from ID to 5D with 0.5m/sec of incoming flow velocity. The experimental results using pitot tube showed in good agreement with results of precious by others study. The results can be applied in the understanding and design of multiple pile array structures.

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National Vacuum Standards from Low to Ultra-high Vacuum (저진공에서 초고진공까지의 국가 진공표준)

  • Hong S. S.;Lim I. T.;Shin Y. H.;Chung K. H.
    • Journal of the Korean Vacuum Society
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    • v.15 no.1
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    • pp.1-13
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    • 2006
  • Vacuum laboratory in Korea Research Institute of Standards and Science (KRISS) was opened in 1983 for establishing and disseminating vacuum standard in Korea. The major three systems such as the ultrasonic interferometer manometer (UIM), the static expansion system (SES) and the dynamic expansion system (DES) with orifice and porous plug conductance are developed. In this study, the standard systems from low to ultra-high vacuum, uncertainty analysis by ISO regulation, and key and bilateral comparison results will be described.

Calibration uncertainty of a capacitance diaphragm gauge (용량형진공계 교정 불확도)

  • 홍승수;신용현;정광화;임인태;우삼용;김정형;최상철
    • Journal of the Korean Vacuum Society
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    • v.10 no.2
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    • pp.173-181
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    • 2001
  • We calibrated a capacitance diaphragm gauge(CDG) of 1,333 Pa range by using ultrasonic interferometer manometer (UIM) that was a national low vacuum standards system. And its uncertainties were evaluated according to International Organization for Standardization(ISO), they were named to A type uncertainty, B type uncertainty, combined standard uncertainty, and expanded uncertainty, We obtained that the combined standard uncertainties were $1.38 \times10^{-2}\; Pa\sim3.03 \times10^{-1} $Pa and the relative uncertainties(combined standard uncertainty/standard pressure) were $2.3 \times 10^{-4}\;Pa\sim7.9 X\times10^{-3} $Pa for this 1,333 Pa CDG.

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Inter-comparison between ultrasonic interferometer manometer and medium vacuum standards by static expansion method (초음파간섭 수은주압력계와 정적법 중진공 국가표준기 상호비교)

  • Hong S. S.;Lim I. T.;Shin Y. H.;Chung K. H.
    • Journal of the Korean Vacuum Society
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    • v.14 no.3
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    • pp.103-109
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    • 2005
  • A new medium vacuum primary standard using the static expansion method was developed in KRISS. In order to evaluate the performance of the equipment, we compared the medium vacuum standard with an ultrasonic interferometer manometer using two capacitance diaphragm gauges, the measuring ranges of which were 133 Pa and 1,333 Pa respectively. The result, Error normalized values, showed that the two standards are coincident each other within the range of combined uncertainty at calibrated pressure of $3pa\;\sim\;100pa$.