This paper describes the development of a piezoelectric level switch, which aims to effectively monitor the level status in high ambient temperatures. In order to adjust the impedance near the resonant frequency and temperature characteristics, the effect of the case and backing layer materials on its performance was analyzed using the finite element method (FEM). The suggested prototype new level switch has three heat-sink plates attached to SUS bar of 230 mm long, and case of PEEK which contains PZT sensing part. To illustrate the validity of this level switch, 10 samples are prepared and investigated the sensing performance through the high and low temperature ambient.
