한국표준과학연구원(KRISS) 물리표준부 질량힘그룹 압력연구실 우삼용 압력 계측 기술 한국표준과학연구원(KRISS) 물리표준부 질량힘그룹 압력연구실 우삼용

KRISS 소개

KRISS 연 혁 국가표준기관으로 한국표준연구소 설립 1975. 12. 24 국가교정업무 시행 1979. 5. 1 한국표준주파수국(HLA) 개국 1984. 11. 24 국제도량형위원회(CIPM) 자문위원회 회원기관 최초 피선 (1988년 이후 현재까지 10개 분야 자문위원회 중 9개 분야 피선) 1988. 10. 11 한국표준과학연구원으로 기관 명칭 변경 1991. 10. 17 국가표준기본법에 국가측정표준대표기관으로 명문화 1999. 2. 8 출연(연)법에 의하여 공공기술연구회 소관 연구기관으로 변경 1999. 3. 15

헌법 제127조 제2항 국가는 국가표준제도를 확립한다. 압력실 View of KRISS

국가표준의 정의 국가 표준 측정표준 : 국제단위(SI)를 바탕으로 측정기술 중심의 표준 산업표준 : 산업규격(KS)에 의한 표준화를 중심으로 하는 표준 측정표준이란 측정의 정밀정확도를 유지하고 호환성을 보장하여 원활한 산업활동과 과학기술 연구를 도모하기 위하여 국가적으로 준용되어야 하는 측정의 기준 1 2 국가표준 국제표준 측정 현장 산업체 연구소 교육기관

BIPM Definitions: kg / m / s “Primary” Reference Standards: ± 0.001% - 0.005% Rdg Transfer Standards: ± 0.01% - 0.05% FS or Rdg Field / Shop working standards: ± 0.1% - 1% FS Process level gauges: ± 1% FS and greater

표준 관련 국제기구 및 국가표준기관 CIPM, OIML, ISO/IEC, ILAC EU APEC NAFTA 국제협력 EUROMET EA APEC APMP APLAC NAFTA SIM IAAC NIST INMS CENAM PTB NPL IMGC NMi KRISS NMIJ NIM NML CMS VMI NIMT NPL-i

압력의 표준

압력의 종류 기압계, 진공계 절대압 게이지압 차압

압력표준기들                                                                                                                                                                                                                                                                            

1 기압: 1 kgf/ cm2 760 mmHg 10 mH2O 100,000 Pa 1013 mb 대기압: 지구 공기층의 무게 * 1644 Toricelli : 수은주 이용 대기압 측정 대기압: 지구 공기층의 무게 (지표면 공기밀도=0.0012 g/cm3) 가로,세로 1 m인 정사각형 면적 작용하는 대기압 : 펌프로 10 m 이상 깊이의 물을 퍼 올릴 수 없다. 물속 10 m 깊이 마다 1 기압씩 증가 - 잠수병1: 상승시 숨을 참아 부피팽창으로 혈액에 공기유입,동맥순환 방해 - 잠수병2: 수중에서 혈액 중에 용해된 질소가 급속한 상승시 기포로 방출 고도가 높아지면 기압이 감소 (6 km 상공은 ½로 감소) 10 톤

The Units Pascal (Pa) N Pa = m2 The SI unit for pressure is: Pressure is force per unit area, but how can we visualize this? Pa = N m2 1 N = a mass of 1 kg accelerated by 1 m/s^2. Therefore we can approx round up std grav. to be ~ 10 m/s^2, and visualizing 1 Pa as 100 g spread out over 1 m^2 N = kg x m/s² 1 m Pa = kg x m/s² m² 1 m

F P = ____ A 압력의 정의 Primary Pressure Standard F P = ____ =  gl h A Mercury manometer Pressure Balance (Piston/Cylinder Unit) Pressure Force = Mass x Acceleration Area Pr P F P = ____ =  gl h A

Mercury Manometer NIST 360 kPa UIM in Metrology 220 Building NPL mercury Barometer

PRESSURE BALANCE From 1.6mm to 35mm Deviation from Ideal Geometry less than 0.0001mm

고압 표준기 Oil : 0 to 1.0 GPa [gauge] Accuracy 0.1% reading to 0.0010 % reading

피스톤/실린더 장치 국가 압력 표준기의 구성 직경 35 mm 부터 1.6 mm 까지 구성 -압력측정범위 : 500 MPa (5000 기압) -유압용 압력표준기의 핵심 장치 텅스텐카바이드 재질 간격 0.001 mm 이하 우수한 원통도(진원도,진직도)

측정식 P2 DUT h P1 STD. P2 = P1 - (f - a)  h  gl

미압(차압)에서 사용하려면? Ooiwa(Japan): Conical Piston/Cylinder

Measurement Principles 1) Force balanced Force resulting from the difference in pressure across the piston is measured by a force balanced load cell Piston is mechanically held at its center and connected to the load cell by a double universal joint system Called force balanced piston gauge because load cell operates on electromagnetic force balance principle. When you push on it, it tells you how hard it is pushing back. Cylinder shape is odd but we’ll worry about that in a moment. The mechanical connection of the piston to the balance is by a double universal joint coupling system. This coupling provides two rotational and two translational degrees of freedom for the piston which is mounted about its center of gravity. This allows the piston to center itself in the cylinder while preventing rotation about its axis.

Lubricating gas is 40 kPa higher than PRef and humidified to 50% RH. Measurement Principles 2) Non-rotating piston Piston is centered in the cylinder by lubricating gas flow through conical gap Lubricating gas is 40 kPa higher than PRef and humidified to 50% RH. Lubricating gas flows to center of cylinder through same passages as piston force coupling system For a piston-cylinder to operate properly, measures must be taken to assure that the piston is centered in the cylinder. Otherwise, their will be friction between the piston and the cylinder with unpredictable effects on the relationship between force on the area and pressure. This causes insensitivity. Many limitations would come from rotating it. So used Dr. Ooiwa’s conical gap system. Conical gap is grossly exaggerated in the illustration. Actual gap is 6 micron in the center and 1 micron at ends. Maximum total gas flow (sum of both chambers) from lubricating has is about 1 ml/min (1 sccm).

Change Bell-jar Pressure 저압(진공)에서 사용하려면? 저압에서 문제점: 피스톤의 무게에 의해 어떤 압력 이하는 측정이 불가 Woo: Residual bell-jar pressure method Change mass Constant Change Bell-jar Pressure  CDG

Calibration Set-up Gauges under calibration Weight loading mechanism filter Precise Pressure Monitor (Barometer) Gauges under calibration Pressure Controller Vac. Pump Motor Controller Stepping Motor N2-Gas RP Piston/Cylinder Monitor Ion Gauge V3 Gas out Gas in V1 V2 V4 V7 V5 V6 Weight loading mechanism Piston

(1) (3) (5) (6) (7) (10) (11) (12) (8) (9) (2) (4)

1 1, 9, 90 2 2, 18, 180 4 4, 36, 360 8 8, 72, 720 3.3 3.3, 30, 300

(for monitor pressure) Pressure controller (for bell-jar pressure) G F E D C B Weight selector & Motor Controller Pressure controller (for monitor pressure) Pressure controller (for bell-jar pressure)

Correction factor : 10 Torr CDG (Absolute type)

고압의 측정

Bridgman: Re-entrant 형 실린더 개발 고압에서 사용하려면? 고압에서 문제점: 피스톤/실린더 사이의 누출이 커져 낙하속도가 빠름 Bridgman: Re-entrant 형 실린더 개발 Newhall : Controlled clearance 형 실린더 개발

1986.Jan Space Shuttle Challenger Disaster O-ring Seal ? The o-ring was invented in 1936 by a 72 year old Danish-born man, Niels Christensen. During the second world war, the US government "bought" critical war-related patents after finding out the big businesses were in violation of Christensen's patent right. Christensen got a lump sum payment of $75,000 for it. 1986.Jan Space Shuttle Challenger Disaster Viton O-ring failure because of cold weather Richard Feynman When an O-ring is frozen there is a TG point (transition to glass) point where it will not bounce back. The tiny leak when the flame reach it acted as a torch against external tank and booster.

고압에서의 밀봉 ?

Bridgman Seal ! The Bridgman seal seals a high pressure volume by the use of an unsupported area to create a higher pressure between two pistons. A viscous material such as copper or soap-stone is used in the generated higher pressure area to seal the intended pressure area.

망가닌게이지 초고압 측정 게이지 압저항게이지 Manganin Wire : 84 % copper, 12 % Manganese, 4% Nickel Precision resistor로 사용 Press. Coef.=2.3 x 10–5 /MPa Cubic face-centered solid solution of Mn and Ni in Copper  isotropic compressibility of the cubic lattice  no permanent change

게이지의 제작 망가닌 선 : 조성 : 86 Cu-12Mn-2 Ni 직경 : 0.12 mm 절연 : 이중 silk 열처리 방법 : 질소 기체, 140도, 48 시간 압력 처리 : 1.4 GPa 2회 초기저항 : 96

망가닌게이지의 압저항 특성

망가닌게이지(fitting eq.)와 표준압력과의 편차

상용 게이지를 이용한 정밀압력의 측정

Strain Gauge type or Silicon Sensor type

Silicon Piezoresistive Pressure Sensor

Silicon Pressure Sensors Media-Isolated Silicon Pressure Sensors Media-isolated silicon piezoresistive sensor Silicone oil fill 316 stainless steel isolation diaphragm

Resonant Silicon Gauges (RSGs) RSG sensor detail Performance Considerations: Zero Instabilities—Short term (hours to days). Random “Noise”—Limits pressure resolution. Tilt Sensitivity— Causes “zero” shifts. Calibration Instabilities—Long term shifts (months to years). High accuracy: ±0.01%, with a maximum allowable input of 500 kPa (130 kPa-range model) K. Harada, K. Ikeda, H. Kuwayama, H. Murayama, Sensors and Actuators, 73 (1999) 261-266.

Quartz Pressure Gauge (1)

Quartz Pressure Gauge (2)

Quartz Pressure Gauge (3)

혈압의 측정

혈압의 측정(Auscultatory Method)

혈압의 측정(Oscillometric Method)

진공의 측정

CDG (Capacitance Diaphragm Gauge) Detect a deflection of thin diaphragm Measure capacitance between diaphragm and electrode Very accurate low pressure gauge Manufacture: MKS, Pfeiffer Vac., Horiba, etc 0.1 torr, 1 torr, 10 torr, 100 torr, 1000 torr MKS Horiba Capacitance diaphragm gauges The capacitance diaphragm gauge (CDG) measures the pressure directly, according to the definition of pressure. The CDG can measure gas type independent from total pressure. The CDG consists of a very thin diaphragm mounted over a reference vacuum cavity. Under pressure load, the diaphragm is elastically bent. Therefore, at atmospheric pressure, the diaphragm is more deflected than in vacuum. The reference vacuum side of the diaphragm and the vacuum side of the base of the vacuum cavity are metallized to form a capacitance. The changing width between the diaphragm and base is a measure of the applied pressure, which is read out as a change in capacitance. With the CDG pressure-sensing principle, total pressure can be measured from above the atmospheric pressure to approximately 10-5mbar. An individual sensor has a dynamic range of only 4 decades, however, which means that at least two sensors are needed to cover the pressure range from 10-5 to 103mbar.

저진공 게이지 피라니게이지 Thermocouple Gauge

Mcleod Gauge 보일의 법칙

중진공 게이지 Spinning Rotor Gauge 용기 405-415 Hz

Bayard-Alpert ionization gauge 고진공 게이지 Ion Gauge Ion Collector Electron Collector (Grid) Source (Filament) Bayard-Alpert ionization gauge

CNT Ion Gauge (KRISS 개발 중, 특허보유) Glass Collector Grid : Cr Triode structure Gas molecule Ionization + e- Ionized molecule CNT

CNT Ion Gauge Collector

감사합니다.