| 摘要 |
<p>The invention relates to control instrumentation and can be used for defectoscopy, structurescopy and thicknessmetry, in particular for inspecting coarse-structure and heterogeneous materials such as concrete, plastics and formations. The inventive low frequency composition converter provided with a mode switch comprises a body, damping fluid, a pressure lid, first and second elements of a piezoelectric cell, a protector embodied in the form of a cone or a pyramid, and a commutator for the elements of the piezoelectric cell. The elements of a piezoelectric cell are electrically isolated from each other, the outlets thereof being connected to the ports of the commutator which enables said outlets to be connected to the outlets of the converter by connecting them inphasely and antiphasely in order to produce the emission of longitudinal and transversal ultrasound waves, respectively, and also for the reception thereof. The top of the protector embodied in the form of a cone or a pyramid is provided with a bit made of a material harder than the material of the remaining part of said protector or of an elastic material. Said invention makes it possible to extend the functionality and the scope of the converter by simplifying the structure design and improving the electroacoustic characteristics thereof.</p> |
