Sonar transducer

Abstract

A sonar transducer mounted on a probe inserted in a vessel or container emits a sonar wave for measuring the level of fluid interfaces within the vessel or container. The sonar transducer includes a housing closed by a diaphragm at one end. A piezoelectric crystal located within the housing is biased against the diaphragm and is electrically connected to an energizing source. The travel time of the sonar wave emitted by the piezoelectric crystal and reflected by the fluid interfaces is measured. The sonic wave measurements are communicated to a microprocessor and the levels of the liquid interfaces within the vessel or container are calculated.

1 . A sonar transducer for detecting the level of liquid to liquid and liquid to solid interfaces in a container, comprising: 
 a) a housing;    b) a diaphragm for emitting a sonar wave through a fluid, said diaphragm being welded across an end of said housing;    c) an annular ring surrounding said diaphragm;    d) a piezoelectric crystal located within said housing adjacent to said diaphragm;    e) means for biasing said piezoelectric crystal against said diaphragm; and    f) means for electrically connecting said piezoelectric crystal to an energizing source.    
   
   
       2 . The sonar transducer of  claim 1  wherein said biasing means comprises a spring mounted within said housing.  
   
   
       3 . The sonar transducer of  claim 2  including an isolation disk located adjacent said piezoelectric crystal.  
   
   
       4 . The sonar transducer of  claim 1  including a single electrical connector connecting said piezoelectric crystal to said energizing source.  
   
   
       5 . The sonar transducer of  claim 3  including a retaining washer located adjacent said isolation disk.  
   
   
       6 . The sonar transducer of  claim 1  wherein said biasing means comprises primary and secondary springs mounted within said housing.