| 摘要 |
<p>An ultrasonic transducer (2) is provided with an acoustic impedance matching layer (6). The matching layer (6) comprises a porous material (7) impregnated from one side (10) with a layer of resin (9), subsequently set. The resin (9) overlaps the edges of the porous material (7) so that the porous material is surrounded by resin on all but the second side (8). The porous material (7) comprises a cellulose nitrate membrane and the resin comprises silicone rubber.</p> |
