A Basic Study on the Water Level Limit Sensor Utilizing Acoustic Impedance Matching

음향임피던스 정합을 이용한 액면레벨 리미트 센서의 기초연구

  • Kim, Cheol-Han (Department of Electronic Engineering, Busan National University) ;
  • Lee, Su-Ho (Department of Electrical Engineering, Dong-A University) ;
  • SaGong, Geon (Department of Electrical Engineering, Dong-A University) ;
  • Lee, Jun-Hee (Div. of Metallurgical Materials & Chemical Engr., Dong-A University)
  • 김철한 (부산대학교 전자공학과) ;
  • 이수호 (동아대학교 전기공학과) ;
  • 사공건 (동아대학교 전기공학과) ;
  • 이준희 (동아대학교 신소재화학공학부)
  • Published : 2005.07.07

Abstract

In this paper, an ultrasonic level limit sensor with a new structure utilizing the acoustic impedance matching is proposed to be able to check it out a change of water-level. 2 PZT resonators with the same property are bonded directly on the polyethylene plate. One is for transmitter as an ultrasonic transducer, the other one is for receiver. In this case, a polyethylene plate will operate as an acoustic guider to transmit a transverse wave between 2 PZT resonators in air. While in the water, a polyethylene plate having a similar acoustic impedance with the water will be emitted an acoustic energy into the water as a longitudinal wave. According to this mechanism, there was a wide difference of acoustic signal output between underwater and in air. As a summary, it is believed that this proposed level limit sensor could be used as a new one with strong toughness from the external electrical and mechanical noise.

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