자기표준장치및교정 2006. 10. 13 한국표준과학연구권전자기그룹 박포규
목차 1. 필요성 2. 자기의단위 3. KRISS 의자기표준현황 4. 자기분야국제동향 ( 표준기관중심 ) 5. KRISS 자기표준소급도 6. 자기표준장치 7. 직류자기장국제비교 8. 교류자기장국제비교 9. 자기관련각종규격 2
1. 필요성 수요증가 ( 우주, 국방, 가전제품등 ) 자기장측정및관련규격에대한현장으로부터문의증가외란자기장으로부터노출 ( 정밀장비의자기장영향 ) 자기관련기술의저변확대및보급교정및시험물량의증가 3
2. 자기의단위 자속 (Magnetic Flux) - SI : Wb(weber), V.s(volt.second) - cgs-emu : Mx. (maxwell) * 1 Wb =1 V.s = 10 8 Mx. 자속밀도 (Magnetic Flux Density) - SI : T(tesla), A/m - cgs-emu : G(gauss), Oe * B=φ /S where B : magnetic flux density (T), φ : magnetic flux (Wb), S : area (m 2 ) 1 Wb = 10 8 Mx. 1 T = 10 4 G 1 Oe = 10 3 /4x(phi) A/m 1 G = 1 Oe (?) * 1 T = 1 Wb/m 2 = 10 4 G 4
3. KRISS 의자기표준현황 6 개의독립된장치로구성 -자속 - 직류 4 ( 측정범위별 4 개 ) -교류자기장표준체계적으로확립 : 자기장표준은세계적수준 -CCEM.M.K1 kc 결과참조 (dc, ac 20 khz 이하 ) : 측정값의국제적인증 -다수의논문게재및 CPEM 발표 -SIRIM, CENAM 에서표준기제작의뢰교정및시험 (2005, 683건, 137백만원 ) 장기적으로위성, 군사, 첨단산업용으로수요증대예상자기측정및관련규격에대한산업현장으로부터문의증가 (IEC, ISO) 기본물리상수측정경험바탕 : 국제적전문가로인정받는계기 5
4. 자기분야국제동향 ( 표준기관중심 ) - NIST( 자기그룹, 자성부품, 나노, 스핀, 바이오등을연구 ) -PTB( 자기분야연구활동활발 ) - NPL( 자기장표준, 자성재료측정 ) - VNIIM( 저자기장분야표준 ) - NMIJ( 자기분야없음, 자성재료, 응용발달 ( 산업체, 학교중심 )) - INRIM( 자기분야연구활발 ) - CENAM( 자기표준분야일부시설 ) - APMP(NIM, SIRIM, Tiwan) -EUROMET(CMI etc) * 국제규격 (ISO, IEC 등에자기장과관련된것이다수, 비행기, 선박등 ) 6
5. KRISS 자기표준소급도 KRISS/VNIIM γ p γ p, γ 4He determination γ 4He NMR standard magnetometer Frequency standard AMR standard magnetometer DC-current standard Electromagnet (high-field range) Helmholtz coil (medium-field range) Calibration of the magnetometer, MF-sources (20 μt ~ 2.5 T) Solenoid, EMF-com. (low-field range) ω ' p = γ P B 7
6. 자기표준장치 1. 자속 (Magnetic Flux) - Fluxmeter Calibrator(Volt-Second generator) - 측정범위 : 0.0001 Wb 10 Wb 2. 교류자기장 (ac Magnetic Flux Density) - 표준 pick-up coil 및헬름홀츠 ( 솔레노이드코일 ) -주파수범위 : 20 khz 이하 3. 저자기장 - 비자성동, 지구자기장상쇄, 정밀솔레노이드, 전류원등을사용 -1.2 mt이하 4. 헬름홀츠코일 ( 1 mt- 40 mt) 5. NMR 및전자석 I (40 mt 0.5 T) 6. NMR 및전자석 II (0.5 T 2.5 T) 8
6-1. 자기표준장치 ( 사진 ) Low-field std (below 1 mt) High-field std-1 (40 mt 0.5 T) Medium-field std (1mT 40 mt) High-field std-2 (0.5 T 2.5 T) 9
6-2. 비자성동및저자기장표준 비자성동구조 10
6-2. 비자성동및저자기장표준 Nonmagnetic building Observatory building Low-field std 11
6-2. 비자성동및저자기장표준 N - S Nonmagnetic Lab. DC EMF compensation 50 m Observatory Lab. Current sources E - W Ver Main 3-component coils He-Cs AMR magnetometer Auxiliary Oil bath He-Cs AMR main current source Current reproducing set Ω + 0 - - + U 0 Solenoid Cs Cs Frequency synthesizer Phase comparator GPS Freq. Std. Cs-AMR controller Time varying EMF compensation 저자기장표준장치 12
6-2. 비자성동및저자기장표준 Field distribution of a simple solenoid (1), corrected with two auxiliary turns of 2-nd order theoretically (2) and practically (3), finally compensated field (4). 3 I 0 Solenoid [{B z (z)-b z (0)} / B z (0)] x 10-6 2 1 0-1 -2 3 1 4 2-3 -30-20 -10 0 10 20 30 Distance from the center along the axis (mm) 13
T)n(ntioaVarieldcFinetiMag10EMtonCompentedEMF1nTCabration-510.00.0.0.9MeasurementTimhour)6-2. 비자성동및저자기장표준 Measurement Building 50 m Nonmagnetic laboratory 50 m Observatory Current source N - S E - W Large 3-axis Helmholtz coil Small 3-axis Helmholtz coil 50Current source Current source Ver Main current source 0Freq. Synthesizer Cs-AMR Signal Electronics Phase comparator Cs-He Solenoid Cs Cs -li3fvariaie(6sa 14
7. 직류자기장국제비교 (CCEM.M.K1) PTB : Physikalisch - Technische Bundesanstalt, Braunschweig, Germany KRISS : Korea Research Institute of Standards and Science, Daejon, Republic of Korea VNIIM : D. I. Mendeleyev Institute for Metrology, St. Petersburg, Russian Federation NML CSIRO : National Measurement Laboratory, Lindfield, Australia UME : Tubutak Ulusal Metroloji Enstitüsü, Gebze-Kocaeli, Turkey NPL : National Physical Laboratory, Teddington, United Kingdom IEN : Istituto Elettrotecnico Nazionale "Galileo Ferraris", Torino, Italy NIM : National Institute of Metrology, Beijing, China CMI : Czech Metrological Institute, Praha, Czech Republic CENAM : Centro Nacional de Metrologia, Queretao, Mexico 15
7. 직류자기장국제비교 (CCEM.M.K1) Institute k dc,i,rv reported value for RT = 109.1 Ω mt/a Results of dc coil constant determination Series of measurements N I k dc,i corrected for current dependence mt/a reported rel. uncertainty u k,i k=1 10-6 weighting factor WF I = I 1 uk,i 1 u k,i k dc,i - k wm nt/a rdi (k dc,i / k wm ) - 1 10-6 KRISS 2.024 105 12 2.024 113 4 0.148-15.7-7.8 VNIIM 2.024 1165 6 2.024 1304 1.1 0.539 1.65 0.82 NML 2.024 73 18 2.024 87 430 ---- 739 365 CSIRO UME 2.055 0 1 2.055 1 278 ---- 31 000 15 000 NPL, NMR 2.024 19 27 n.c. 2.024 19 73 0.0083 61.3 30.3 NPL, ESR 2.024 49 15 2.024 56 64 ---- 430 212 IEN 2.023 53 4 2.023 56 222 ---- - 569-281 NIM 2.024 108 10 n.c. 2.024 108 8.6 0.069-20.7-10.2 CMI 2.024 195 3 2.024 206 35 0.017 77.3 38.2 CENAM 2.026 43* 3 2.026 48 62 ---- 2351 1162 PTB - 33 2,024 1336 2.7 0.22 4.85 2.4 CENAMPT 2.024 158 2 2.024 201 32 ---- 72 35.5 B 16
8. 교류자기장국제비교 (CCEM.M.K1) P(f) = ((k( f ) / k dc ) I ) fit and (k(f)/k dc ) I 1.012 1.010 1.008 1.006 1.004 1.002 1.000 0.998 0.996 0.994 0.992 2 σ 2 σ KRISS VNIIM NIM NPL IEN CMI UME PTB 10 100 1000 10000 f in Hz 17
9. 자기관련각종규격 자기차폐율측정 (ASTM A 698/A 698M-02 ) 선박용자기콤파스의안전거리측정 (ISO 694) 열량계자기장관련규격 (OIML R 75-2) 전화수화기자기장측정 (IEEE std 1027) 선박용나침의 (ISO449, ISO2269) 감사합니다 18