0.01～1Hz水声声压标准装置的研究

The Research of Underwater Acoustics Pressure Standard in the Frequency Band of 0.01 to 1 Hz

为了精确测量和分析低于1Hz频率的甚低频水声信号,建立了0 01～1Hz水声声压标准装置。装置由声压生成系统、正弦振动系统和电子测量与控制系统所组成,采用静水压激励法产生0 01～1Hz频率范围内变化的声压。在低频段的声压值为195 86Pa。在高频段的声压值由于受振动惯性力的影响,随频率的增高而减小,但通过对等效高度的精确求定也可精确已知。装置可直接校准甚低频水听器的开路电压灵敏度值,校准值的扩展不确定度为0 3dB(P=95%)。

In order to measure and analyze the very low frequency underwater acoustic signals, an underwater acoustics pressure standard in the frequency band of 0.01 Hz to 1Hz is established. This standard consists of acoustics pressure production system, sinusoidal vibration system and electronic measurement and controlling system. And the hydrostatic excitation method is used to produce the acoustics pressure variation in the frequency band of 0.01 Hz to 1 Hz. At the low frequencies, the acoustics pressure values are 195.86 Pa. Owing to influence of the vibration inertia force, the acoustics pressure values decrease with the frequency increasing at the high frequencies. But they also can be accurately determined through measuring the equivalent height accurately. The standard can also be used to calibrate the open-circuit voltage sensitivity of the very low frequency hydrophone, and the expand uncertainty of the calibrated value is 0.3 dB (P=95%).