Beam Patterns Unaffected by Vessel 



100 KC/S 



OUT OF VESSEL 



IN VESSEL (OPSIG) 



330 



270° 



210 



150° 



180 



Close correspondence of directivity pat t e rns of 

 t ransduc e r within and w i thout the capsule ind i cat es 

 that transmission properties of the plastic are 

 linear. Beam patterns are unaffected by the pres- 

 sure of the vessel. 



11 



