An on-line calibration hydrophone with electrostatic actuator

Abstract

On-line sensitivity calibration of hydrophones is of considerable significance for their practical application. An on-line method using an electrostatic actuator is proposed in this paper for a radially polarized cylindrical piezoelectric hydrophone. The theory of this calibration method is analyzed. A calibration structure with an electrostatic actuator is designed, and is integrated with the hydrophone sensing element. The sensitivity and frequency characteristics of the electrostatic actuator are measured experimentally. The sensitivity of the hydrophone is calibrated and compared with its free-field sensitivity. Uncertainty analysis shows that the expanded uncertainty of the proposed calibration method is about 1.1 dB at a confidence probability of 95%, which meets the uncertainty requirements for hydrophone sensitivity calibration.

创新点

针对径向极化的圆柱形压电水听器,提出了一种基于静电激励机制的灵敏度在线自校准方法,解决了水听器使用中灵敏度变化,而又不便拆卸进行校准的难题。文中建立了静电激励自校准模型,设计了圆柱形压电陶瓷水听器及其静电激励器,并制作相应的部件集成了自校准水听器样品。通过静电激励器校准实验,得到了静电激励器的灵敏度频率响应特性,并利用水听器的自由场校准实验,验证了基于静电激励机制的在线自校准方法的可行性。实验不确定性分析表明,95%置信概率下,该校准方法的扩展不确定度为1.1dB,满足测量水听器校准的不确定度要求。