DOI QR코드

DOI QR Code

비접촉식 광 점퍼 코드 개발 및 광 전송 성능 평가

Development of Non-Contact Fiber Jumper Cord and Evaluation of Light Transmission Performance

  • 김헌영 (한국철도기술연구원 첨단소재연구팀) ;
  • 강동훈 (한국철도기술연구원 첨단소재연구팀)
  • 투고 : 2016.09.24
  • 심사 : 2016.10.13
  • 발행 : 2016.10.30

초록

최근 많은 장점으로 기존 전기식 센서를 대체하여 그 적용 영역을 빠르게 넓혀가고 있는 광섬유 센서는 센서부에서 계측기 사이의 신호 전달을 위해 광 어댑터와 광 점퍼 코드와 같은 광소자를 사용하게 된다. 광 어댑터를 이용하여 신호 전달을 하는 경우 단면이 서로 맞닿게 되어 이물질에 의해 코어 부분에 손상이 발생할 수 있으며, 이는 광 손실 및 광 접속 불능을 유발할 수 있다. 따라서, 본 연구에서는 지속적인 유지보수를 필요로 하는 문제들을 근원적으로 해결할 수 있는 대안으로 비접촉식 광섬유 점퍼 코드를 개발하였으며 그 전송 성능을 평가하였다. 시험 결과, 기존의 접촉식 광 점퍼 코드는 2 mm의 간극에서 광 신호 전송이 불가능한데 반해 비접촉식 광 점퍼 코드의 경우 초기 광 손실은 상대적으로 크지만 간극이 증가하더라도 약 7 mm 정도까지 안정적으로 신호 전송이 가능하였다. 따라서, 패치 코드가 광센서 간 신호 전송을 위한 케이블임을 고려할 때 외부의 환경적 요인에 대해 더 우수한 신호 안정성을 가진 비접촉식 패치 코드가 접촉식 패치 코드에 비해 현장 적용성이 더 뛰어남을 확인하였다.

Recently, fiber optic sensors, which have many advantages are being applied in various fields by replacing conventional electric sensors. To transmit the light signals between an interrogator and a sensor head, optical components such as an optical adaptor and optical jumper cords are generally used. When signals are transmitted using an adaptor, the end surface of each jumper cord is faced together. If alien substances exist on the core surface of an optical fiber, those can cause light transmission loss and signal disappearance. For this reason, non-contact fiber jumper cords are developed to overcome the problems that require continual attention. The light transmission performance of non-contact fiber jumper cords are also evaluated. From the test results, conventional fiber jumper cords are unable to transmit the signals over 2 mm cavity between the ends of both cords. Otherwise, non-contact fiber jumper cords can transmit the signals with stability up to the cavity of 7 mm though they have more transmission loss than the conventional ones. Consequently, non-contact fiber jumper cords that have better signal stability than conventional ones in environments are highly recommended in field applications, especially if they play a role as a cable for signal transmission between fiber optic sensors.

키워드

참고문헌

  1. W. A. Gambling, H. Matsumura, C. M. Ragdale and R. A. Sammut, "Measurement of radiation loss in curved single-mode fibres," Microwaves, Optics and Acoustics, IEE Journal, Vol. 2, No. 4, pp. 134-140 (1978) https://doi.org/10.1049/ij-moa.1978.0030
  2. W. A. Gambling and H. Matsumura, "Propagation characteristics of curved optical fibers," IEICE Transactions (1976-1990), Vol. 61, No. 3, pp. 196-201 (1978)
  3. J. C. Baggett, T. M. Monro, K. Furusawa, V. Finazzi and D. J. Richardson, "Understanding bending losses in holey optical fibers," Optics Communications, Vol. 227, No. 4, pp. 317-335 (2003) https://doi.org/10.1016/j.optcom.2003.09.070
  4. K. H. Lee, B. J. Ahn and D. H. Kim. "Fiber optic displacement sensor system for structural health monitoring," Journal of the Korean Society for Nondestructive Testing, Vol. 31, No. 4, pp. 374-381 (2011)
  5. H. Y. Kim and D. H. Kim, "Sensor system for multi-point monitoring using bending loss of single mode optical fiber," Journal of the Korean Society for Nondestructive Testing, Vol. 35, No. 1, pp. 39-45 (2015) https://doi.org/10.7779/JKSNT.2015.35.1.39
  6. J. H. Lee, D. H. Kim and I. K. Park, "Application of a fiber Fabry-Perot interferometer sensor for receiving SH-EMAT signals," Journal of the Korean Society for Nondestructive Testing, Vol. 34, No. 2, pp. 165-170 (2014) https://doi.org/10.7779/JKSNT.2014.34.2.165
  7. H. Y. Kim, J. H. Lee and D. H. Kim, "Muscular condition monitoring system using fiber Bragg grating sensors," Journal of the Korean Society for Nondestructive Testing, Vol. 34, No. 5, pp. 362-368 (2014) https://doi.org/10.7779/JKSNT.2014.34.5.362
  8. J. B. Ihn and F. K. Chang, "Pitch-catch active sensing methods in structural health monitoring for aircraft structures," Structural Health Monitoring, Vol. 7, No. 1, pp. 5-19 (2008) https://doi.org/10.1177/1475921707081979
  9. Y. J. Rao, D. J. Webb, D. A. Jackson, L. Zhang and I. Bennion, "In-fiber Bragg-grating temperature sensor system for medical applications," Journal of Lightwave Technology, Vol. 15, No. 5, pp. 779-785 (1997) https://doi.org/10.1109/50.580812
  10. D. H. Kang, C. U. Kim and C. G. Kim, "The embedment of fiber Bragg grating sensors into filament wound pressure tanks considering multiplexing," NDT&E International, Vol. 39, pp. 109-116 (2006) https://doi.org/10.1016/j.ndteint.2005.07.013
  11. A. Grillet, D. Kinet, J. Witt, M. Schukar, K. Krebber, F. Pirotte and A. Depre, "Optical fiber sensors embedded into medical textiles for healthcare monitoring," IEEE Sensors Journal, Vol. 8, No. 7, pp. 1215-1222 (2008) https://doi.org/10.1109/JSEN.2008.926518
  12. W. Chung and D. Kang, "Full-scale test of a concrete box girder using FBG sensing system," Engineering Structures, Vol. 30, No. 3, pp. 643-652 (2008) https://doi.org/10.1016/j.engstruct.2007.05.003
  13. D. Kang, D. H. Kim and S. Jang, "Design and development of structural health monitoring system for smart railroad-gauge-facility using FBG sensors," Experimental Techniques, Vol. 38, No. 5, pp. 39-47 (2014) https://doi.org/10.1111/j.1747-1567.2012.00844.x