고압의 측정

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

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 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.

초고압 측정 게이지 Manganin Wire : 84 % copper, 12 % Manganese, 4% Nickel Precision resistor 로 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 망가닌게이지 압저항게이지

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

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

Resonant Silicon Gauges (RSGs) 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) RSG sensor detail K. Harada, K. Ikeda, H. Kuwayama, H. Murayama, Sensors and Actuators, 73 (1999)

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

피라니게이지 Thermocouple Gauge 저진공 게이지

Mcleod Gauge 보일의 법칙

용기 Hz Spinning Rotor Gauge 중진공 게이지

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

CNT Ion Gauge (KRISS 개발 중, 특허보유 )

CNT Ion Gauge Collector

감사합니다.