电容式次声传感器频率特性研究

Study of frequency properties of infrasound condenser microphone

研究了次声传感器的频率特性的分布情况,定量分析了次声传感器组成部件参数对幅频特性的影响。通过求解次声传感器前后腔内的次声波动态方程得到频率响应模型和截止周期误差模型,选取一批进气口、均压管和膜片相对误差在5%之内的部件,与体积相对误差控制在0.1%之内的前后腔体部件组装成32个次声传感器并对其进行校准实验,校准结果表明该批传感器的截止周期分布在540 s至610 s区间,根据截止周期误差模型计算的理论变化区间范围为530.6 s至614.9 s区间,二者的一致性验证了模型的有效性,为控制次声传感器截止周期一致性和传感器批量精细设计提供了理论指导。

Distribution of frequency of sensor is studied and influence on amplitude-frequency response is analyzed quantitatively by parameters of different parts of the sensor.The models of the response and its error in cut-off period of the sensor are developed by solving dynamic equation for infrasonic wave field in front and rear chambers.A batch of components with relative error less than 5%of inlets,leaks and diaphragms,and front and rear chambers with relative volume error less than 0.1%are chosen to assemble 32 sensors that are tested by calibration experiment.The calibration results show that the cut-off period is in the range from 540 s to 610 s,while the theoretical period based on cut off period error model is in the range from 530.6 s to 614.9 s.The obtained consistency between calibration and theoretical results justifies the validity of the model developed.The models provide theoretical guidance for controlUng cut off period of sensors and fine batch design.