| 摘要 |
PURPOSE:To obtain a ultrasonic wave of 10-200mHz with high performance by receiving and transmitting a ultrasonic wave on an electrode surface of a polariized piezoelectric body obtained by impressing a voltage between adjacent electrodes and by making the piezoelectric body under electrode into a body for absorbing a ultrasonic wave. CONSTITUTION:An electrode 6 is formed on a ceramic 5 in such a manner that corrosion-resistant metals such as Au and Ni are deposited or spattered, because the electrode 6 is immersed in a ultrasonic wave propagating medium 7 and exposed in steam in air. When a voltage is impressed on the electrode 6, the produced ultrasonic wave propagates the ceramic 5 and the medium 7, while a ultrasonic wave for propagating the medium 7 reaches a body 8 to be measured, and is reflected or transmitted after obtaining of information of the object to be measured. On the other hand, a ultrasonic wave for propagating the ceramic 5 is reflected at end face 9, whereby unwanted waves are produced. This can be prevented if a length L of the ceramic 5 is selected so that a ultrasonic wave will be attenuated in propagation and will turn out to be negligible. |
