Investigation of the Flow Dependence of a FET-Type Dissolved Oxygen Sensor and Its Reducing Method

FET형 용존 산소 센서의 유속에 의한 영향 조사와 감쇄 기법

  • Jeong, H. (Dept. of Sensor Eng., Kyungpook Nat'l University) ;
  • Kim, Y.J. (School of Electronic & Electrical Eng., Kyungpook Nat'l University) ;
  • Lee, Y.C. (School of Electronic & Electrical Eng., Kyungpook Nat'l University) ;
  • Sohn, B.K. (School of Electronic & Electrical Eng., Kyungpook Nat'l University)
  • 정훈 (경북대학교 센서공학과) ;
  • 김영진 (경북대학교 전자전기공학부) ;
  • 이영철 (경북대학교 전자전기공학부) ;
  • 손병기 (경북대학교 전자전기공학부)
  • Published : 2001.05.31

Abstract

Recently, FET type dissolved oxygen sensor was proposed to overcome the disadvantages of the amperometric Clark-type sensor. The inherent problem of the proposed sensor, however, is the flow dependence of the sensor performances since the proposed sensor detects the pH change in close proximity to the working electrode. In this study, we decided the direction which minimize the flow effect in FIA(flow injection analysis) system. And a hydrodynamic buffer layer which can reduce the flow dependence were proposed. The suggested buffer-layers were formed onto sensing area and working electrode with mixed polymer matrix of TEOS(tetraethylorthosilicate) and DEDMS(diethoxydimethylsilane).

최근 전류 법적인 Clark형 센서의 단점을 극복하기 위해 FET형 용존 산소 센서가 제안되었다. 그러나 제안된 센서의 출력은 작업전극에서 발생하는 pH의 변화를 감지하기 때문에 유속에 대한 영향을 받는다. 본 논문에서는 FIA(flow injection analysis)를 이용하여 유속의 영향을 최소화 할 수 있는 방향을 결정하였다. 그리고 완충막을 작업전극과 감지막 위에 형성시켜 작업전극과 감지부가 측정용액에 직접 노출되어 용액의 유동에 의해 센서의 출력이 불안정한 문제를 개선하였다. TEOS(tetraethylorthosilicate)와 DEDMS(diethoxydimethylsilane)를 혼합하여 졸-겔법으로 완충막을 형성하였다.

Keywords

References

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