| 摘要 |
PURPOSE:To prevent a vibration noise due to the current of water and waves with a simple constitution, by supporting a hydrophone through a supporting part which is provided in the symmetric axis of inside and outside cylinder parts having a symmertric structure and by forming an airtight room between both cylinder parts. CONSTITUTION:An inside cylinder part 21 made of duralumin is arranged concentrically in the inside of an outside cylinder part 20 having a cylindrical piezoelectric conversion element, and both ends of indide and outside cylinder parts 20 and 21 are fixed to a ring-form end wall part 22 made of duralumin by adhesion to form an airtight chamber 23 between both cylinder parts, and a ring-form supporting part 24 is protruded in the center of the inside of the inside cylinder part 21. In a hydrophone H constituted in this manner, deformation due to acoustic pressure of the outside cylinder part 20 is not impeded because the airtight chamber 23 is formed, and the sum of electric charge becomes zero and does not appear as an electric output on an electric output lead wire 32 because vibration propagated from the supporting part 24 to the outside cylinder part 20 is dispersed symmetrically. |
