• 제목/요약/키워드: Force Standards

검색결과 334건 처리시간 0.035초

100 kN Deadweight Force Standard Machine and Evaluation

  • Park Yon-Kyu;Kim Min-Seok;Kim Jong-Ho;Kang Dae-Im;Song Hou-Keun
    • Journal of Mechanical Science and Technology
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    • 제20권7호
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    • pp.961-971
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    • 2006
  • A deadweight force standard machine is a mechanical structure that generates force by subjecting deadweights to the local gravitational field. The Korea Research Institute of Standards and Science (KRISS) developed and installed a 100 kN deadweight force standard machine for national force standards. It can generate forces from 2 kN to 110 kN in increments of 1 kN. The uncertainty of the force machine was estimated and declared as $2\times10^{-5}$. This 100 kN deadweight force machine was compared with the 500 kN deadweight force standard machine at KRISS and the 20 kN and 50 kN deadweight force standard machines at the National Metrology Institute of Japan (NMIJ). The measurement results showed good agreement between the deadweight force machines, and the accuracy level of the 100 kN deadweight force machine was verified.

내장형 힘 변환기를 이용한 대용량 힘 표준기 개발 (Development of a Large Force Standard Machine with Built-in Force Transducers)

  • 강대임;이정태;송후근;김엄기
    • 대한기계학회논문집A
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    • 제24권3호
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    • pp.667-675
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    • 2000
  • Force measuring devices should be calibrated to guarantee their test results. In order to establish the force standards in Korea, deadweight machines of 5 kN, 20 kN, 100 kN and 500 kN capacity and a hydraulic force standard machine of 2 MN capacity were installed at the Korea Research Institute of Standards and Science(KRISS). As heavy industries in Korea have been developed, we should measure large forces over 2 MN capacity precisely in industries. We developed a 10 MN force standard machine with built-in force transducers which is more compact and cheaper than hydraulic force standard machines which have been widely used as large force standards in most national metrology laboratories. Test results reveal that the relative expanded uncertainty of the force machine is less than 4.1 $\times$ 10-4 in the range of 1 MN-4.5 MN.

나노 힘 측정 및 표준 (Nano Force Metrology and Standards)

  • 김민석;박연규;최재혁;김종호;강대임
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.59-62
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    • 2005
  • Small force measurements ranging from 1 pN to $100{\mu}N$, we call it Nano Force, become the questions of common interests of biomechanics, nanomechanics, material researches, and so on. However, unfortunately, quantitative and accurate force measurements have not been taken so far. This is because there ,are no traceable force standards and a calibration scheme. This paper introduces a quantitative force metrology, which provides traceable link to SI (International Systems of Units). We realize SI traceable force ranging from 1 nN to $100{\mu}N$ using an electrostatic balance and disseminate it through transfer standards, which are self-sensing cantilevers that have integrated piezoresistive strain gages. We have been built a prototype electrostatic balance and Nano Force Calibrator (NFC), which is an AFM cantilever calibration system. As a first experiment, we calibrated normal spring constants of commercial AFM cantilevers using NFC. Calibration results show that the spring constants of them are quite differ from each other and nominal values provided by a manufacturer (up to 240% deviation).

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Build-up 기법을 이용한 대용량 힘 측정 시스템 개발 (Large Force Measuring System Using Build-up Technique;)

  • 강대임;송후근
    • 대한기계학회논문집A
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    • 제21권3호
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    • pp.477-484
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    • 1997
  • This paper describes the build-up force measuring system of 9.9 MN capacity which consists of nine force transducers of each having 1.1 MN capacity. We have specially designed a force transducer for a build-up force measuring system to reduce the uncertainty of a build-up system and to accomodate the new test procedure for a build-up system. It reveals that the relative uncertainty of the force measuring system is less than 1.5*10$^{-4}$ in the ran9e of 1-4.5 MN irrespective of loading direction. The force measuring system may be used to calibrate a 10 MN force standard machine to be used as a large force standard in Korea.

미국학교도서관기준에 나타난 SLMP의 교육적 이념 (The Educational Idea Presenting In the SLMP's Standards)

  • 김효정
    • 한국문헌정보학회지
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    • 제12권
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    • pp.121-147
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    • 1985
  • In the modern communicative age, the standards of the school libraries are the qualitative guarantee on the services of school libraries or school library media programs, as the guidline, the active guide, the policy documentation and criteria for the professional excellence. The standards of SLMP were revised the sixth time by the school library profession(ALA) with the members or agency of NEA in the U.S. There are the first standard was a quantitative; 'the Certain Report'(by A.L.A., 1920) appearing that the school library is the heart of the school, 2nd 1925; turning up the teaching material source and personel, 'School Libraries for today and tomorrow' (by AASL, 1945) incluseing the instructional materials and the 7th educational ideas in the quantitative feature, 'Standards for School Library Programs' (by AASL, 1960) expressing the instructional material center, communicative environment, learning and teaching laboratory, 'Standards for school media programs' (by DAVI & AASL, 1969) implicating the instructional resource, learning and teaching laboratory, the condition precedent of qualitative education for excellence, 'Standards for media programs; District/school (by AASL & AECT, 1975) containing the improving user's educational experience and personal freedom on the use of SLMP's services. Through changing the standards of SLMP in the US, We have known that the main educational idea in the standards are; (1) SLMP is the instructional force and resource for qualitative, excellence education by learning and teaching laboratory, instructional resource, communicative environment (2) SLMP is the actualizing force and resource for user's self-realization by intellectual and personal excellence, individualizing, humanizing and personalizing education.

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Experimental Demonstration of Enhanced Transmission Due to Impedance-matching Si3N4 Layer in Perforated Gold Film

  • Park, Myung-Soo;Yoon, Su-Jin;Hwang, Je-Hwan;Kang, Sang-Woo;Kim, Deok-kee;Ku, Zahyun;Urbas, Augustine;Lee, Sang Jun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.359-359
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    • 2014
  • In this study, surface plasmon resonance structures for the selective and the enhanced transmission of infrared light were designed. In order to relieve the large discontinuity of refractive index between air and metal hole array, $Si_3N_4$ was used as the impedance matching layer. Experimental parameter were calculated and determined in advance by the rigorous coupled wave analysis (RCWA) simulation, and then the experiment was carried out. A 2-dimensional metal hole array structures were patterned on the size of $1{\times}1cm^2$ GaAs substrate using photolithography process, and 5 nm thick Ti, 50 nm thick Au were deposited by E-beam evaporator, respectively. Subsequently, $Si_3N_4$ films with various thicknesses (150, 350, 550, and 750 nm) were deposited by plasma enhanced chemical vapor deposition (PECVD). For the comparison, transmittance of specimens with and without $Si_3N_4$ was measured using Fourier transform infrared spectroscopy (FTIR) in the range of $2.5-15{\mu}m$. Furthermore, the surface and the cross-sectional images were collected from the specimens by scanning electron microscopy (SEM). From the results, it was demonstrated that the transmittance was enhanced up to 80% by the deposition of 750 nm $Si_3N_4$ at $6.23{\mu}m$. It has advantage of enhanced transmission despite the simple fabrication process.

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