화학공학소재연구정보센터
Korean Journal of Materials Research, Vol.13, No.10, 651-657, October, 2003
공간주파수대역에서 기저대역 확장을 통한 원전 대비시험편과 대비 보정 시험편의 초음파 영상 개선
Ultrasonic Images Enhancement of the SS Reference Specimen and the Reference Calibration Block for NPPs by the Combining Bases of Support for Spatial Frequency
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Ultrasonic microscope has been used to detect the defects on surface or inner solid. Conventionally, it has used at a single operating frequency. The resolution and quality of the measured images are determined by a characteristic of the transducer of the ultrasonic microscope. The conventional ultrasonic microscope has been used envelope detector to detect the amplitude of reflected signal, but the changes in amplitude is not sensitive enough for specimen with microstructure that in phase. In this paper, we have studied multi-frequency depth resolution enhancement with ultrasonic reflection microscope for the reflectors of a stainless steel reference specimen and a reference calibration block to be used as the material in nuclear power plants for ISI, PSI. Increased depth resolution can be obtained by taking two, three-dimensional images at more that one frequency and numerically combining the results. As results of the experiment, we could get enhanced images with the rate of contrast in proportion and high quality signal distribution for the image to the changing rate of depth for the reflectors of the two kinds of specimens.
  1. Kino GS, Acoustic waves, Prentice-Hall (1987) (1987)
  2. Rugar DJ, Appl. Phys., 56, 1338 (1984)
  3. Carlin B, Ultrasonics, McGraw-Hill, New York 1949 (1949)
  4. McMaster RC, Nondestructive Testing Handbook vol. II, New York: Ronald (1959) (1959)
  5. Abdullah A, Acoustic Reflection Microscope, Ph. D. dissertation, Stanford Univ. (1978) (1978)
  6. Thompson DO, Chimenti DE, Eds., Review of Progress in Quantitative Nondestructive Evaluation 6A, New York: Plenum Press (1987) (1987)
  7. Fraser JD, The Design of Efficient Broadband Ultrasonic Transducers, Report GL No. 2973, Stanford University, May (1979) (1979)
  8. Weglein RD, Wilson RG, Electron. Lett., 14, 352 (1978)
  9. Spencer M, Fundamentals of Light Microscopy, Cambridge: Cambridge University Press (1982) (1982)
  10. Oppenheim AV, Signal and system, Prentice-Hall (1983) (1983)
  11. Briggs A, Acoustic Microscopy, Oxford (1992) (1992)
  12. Kessler LW, Yuhas DE, Proc. IEEE, 64, 487 (1979)