| 摘要 |
PURPOSE:To perform the analysis of AE waves, to provide an excellent fit to a curved surface, and to obtain excellent sensitivity with respect to a material to be measured having low impedance, by using macromolecular PVDF (polyvinylidene fluoride) as a piezoelectric body, and imparting flexibility to the entire body. CONSTITUTION:A piezoelectric element 11 is formed by using macromolecular PVDF as a piezoelectric body 12, performing polarization of the piezoelectric body 12 and providing electrodes 13 and 14 in the perpendicular direction with respect to the polarization on both surfaces. Since a shield case 15 is made of wire gauze, the case have flexibility and fits into a material to be measured even it has the curved surface. The outer electrode 13 of the piezoelectric element 11 is placed over the material to be measured. A measuring device of a voltage or a current is connected to terminals 16 and 17 of the shield case 15. The sound waves or elastic waves of the material to be measured are received by the outer electrode 13. The vibration generated in the piezoelectric element is electrically detected by the measuring device. |
