| 摘要 |
PURPOSE:To improve remarkably the distance resolution of the titled transducer by forming the 1st rear side member with nearly the same member as a piezoelectric element and decreasing the reflecting wave from the 1st rear member. CONSTITUTION:A piezoelectric element 1 is fixed to the 1st rear member 13 via a drive electrode 1A and a front plate 14 is fixed to the opposite side (that is, body 80 to be checked) via a ground side electrode 1B. As the piezoelectric element 10, a ceramic material (especially PZT group) having an acoustic impedance Z0(=25.7X10kg/m<2>.s) is used. Further, as the 1st rear member 13, the block of the same element as that of the piezoelectric element 10 is used while unpolarized and its acoustic impedance ZB is set to ZB=1.17Z0. Further, as the 2nd rear member 20, a composite material made of tungsten and epoxy resin whose acoustic impedance ZB is set as ZB=0.6Z0 is used.
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