Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
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Development and Calibration of a Plate Type Eddy Current Standard

평판형 와전류 표준 시험편의 개발 및 교정

  • Kim, Young-Joo (Safety Metrology Group, Korea Research Institute of Standards and Science) ;
  • Kim, Young-Gil (Safety Metrology Group, Korea Research Institute of Standards and Science) ;
  • Ahn, Bong-Young (Safety Metrology Group, Korea Research Institute of Standards and Science) ;
  • Yoon, Dong-Jin (Safety Metrology Group, Korea Research Institute of Standards and Science)
  • 김영주 (한국표준과학연구원 안전그룹) ;
  • 김영길 (한국표준과학연구원 안전그룹) ;
  • 안봉영 (한국표준과학연구원 안전그룹) ;
  • 윤동진 (한국표준과학연구원 안전그룹)
  • Published : 2007.10.30
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Abstract

Eddy current standard including an artificial slot for the calibration of absolute type surface probe was fabricated. Developed eddy current standard has the electric conductivity and dimensions, and contains artificial slot as established in ASTM E 1629. The width and depth of artificial slot are 0.1 mm and 0.5 mm respectively. This slot was only possible to measure the depth on the two side edges, and impossible for the middle part with general measurement tools. The ultrasonic test method was applied for measuring depth of the middle part of the artificial slot in the standard. Using this method the dimension could be measured successfully with uncertainty about $15\;{\mu}m$. Calibration of eddy current standard for the absolute probe can be performed by this technique.

절대형 와전류 탐촉자 인증 시험에 사용되는 인공 결함이 포함된 와전류 표준 시편을 개발하였다. 개발된 표준 시편은 ASTM E 1629에서 규정한 전기 전도도를 지니고 인공 결함을 포함하며 전체 형상과 규격, 인공 결함의 규격을 만족한다. 인공 결함의 규격은 너비 0.1 mm, 깊이 0.5 mm이다. 이 인공 결함은 기존에는 양 측 끝단만 측정이 가능하고 중간 부위의 측정이 불가능하여 가운데 부위의 인증이 불가능하였으나 초음파 기술을 적용하는 새로운 방법을 도입하여 $15\;{\mu}m$ 정도의 불확도로 측정을 하여 교정이 가능하도록 하였다.

Keywords

References

  1. Draft International Standard ISO/DIS 15548-1, 'Non-destructive Testing-Equipment for Eddy Current Examination-Part 1: Instrument Characteristics and Verification' (2006)
  2. Draft International Standard ISO/DIS 15548-2, 'Non-destructive Testing-Equipment for Eddy Current Examination-Part 2: Probe Characteristics and Verification' (2006)
  3. Draft International Standard ISO/DIS 15548-3, 'Non-destructive Testing-Equipment for Eddy Current Examination-Part 3: System Characteristics and Verification' (2006)
  4. ASTM E1629 'Standard Practice for Determining the Impedance of Absolute Eddy-Current Probes' R(200l)
  5. ASTM E1004 'Standard Practice for Determining Electrical Conductivity Using the Electromagnetic (Eddy-Current) Method,' (1999)
  6. Young-Joo Kim et al. 'Measurement of the depyh of narrow slotted sections in eddy current reference standards,' Metrologia 44 pp. 53-56 (2007) https://doi.org/10.1088/0026-1394/44/1/007
  7. 한국표준과학연구원, 측정 불확도 표현 지침 (KRI5S-99-070-SP) (1999)