ACOUSTIC TRANSDUCER Russian patent published in 1999 - IPC

FIELD: instrumentation engineering. SUBSTANCE: invention refers specifically to devices determining level of boundary of separation of media in closed vessels by acoustic method. Proposed transducer is intended for operation in closed vessels with gaseous atmospheres. Transducer includes piezoelement with matching layer and screen placed in all-metal case and cylindrical metal branch pipe composed of two tightly interconnected parts. One end of first part of branch pipe is joined tight to side surface of case, butt of the other end has starting chamfer on internal surface and collar for outline welding is located on external surface. External surface of this part of branch pipe has thread. Outer diameter of collar for outline welding is smaller than inner diameter of thread by two heights of weld of outline welding. Second part of branch pipe has average diameter less than 1/1/6λ, where λ is length of sound wave in material of branch pipe on working frequency of transducer. One end of it carries stepped bushing with central hole for signal wires. Step of smaller diameter of this bushing is installed inside first part of branch pipe and its external surface has grooves for accommodate polymer sealing rings. Step of larger diameter has collar for outline welding resting against proper collar of first part of branch pipe. Both parts of branch pipe are joined with the aid of coupling nut put on thread of first part of branch pipe to positive stop against step of larger diameter of stepped bushing. Design of transducer makes it possible to use during assembly both releasable and weld connections, transducer is capable of operation in corrosive gaseous atmospheres, is adaptable to manufacture, is easy in handling as it allows length of branch pipe to be changed and provides for high operational reliability. EFFECT: transducer can operate in corrosive gaseous atmosphere, is adaptable to manufacture, easy in handling and provides for high operational reliability. 1 cl, 1 dwg