Abstract: To point charge, the expression of the induced charge on the electrostatic sensor was calculated. When the point charge moved in the measurement zone, the spatial filtering velocity measuring method was obtained with the amplitude-frequency response of the probe and gate function seemed, and then, in the entire frequency range of speed measurement principle was all effective. The measurement speed expression of spatial filtering method was established with the characteristic frequency of signal spectrum analysis and this method can be used for measuring the flow velocity of the gas-solid two phase flow. The spectral characteristics were obtained with using the transition matrix of the spectral density and analyzing their spectrum segment features of the electrostatic sensor output voltage signal, and then the velocity measurement was completed by finding the characteristic frequency. The flow velocity measurement method was verified by experiment, and the scale factor and the correction factor was calibrated through experiment.

Key words: Spatial filtering , Speed , Gas / solid two-phase flow , Electrostatic sensor , Since the spectral density

摘要： 　    以点电荷为例，计算静电感应电极上感应电荷的表达式，点电荷在测量区内运动，根据电极的幅频响应，并将感应电荷表达式看作门函数，得到空间滤波法测速原理，并且在整个频率范围内对测速原理进行推广。利用信号频谱分析中的特征频率建立空间滤波测量速度，其可以用于静电传感器测量气／固两相流的流动速度表达式。采用自谱密度的转换矩阵，对静电传感器输出电压信号作自谱密度分析，得到其频谱特性，找到特征频率（峰幅频率）完成速度测量。通过实验验证其方法是可行的，并通过实验来校正比例因数和校正因子。

关键词: 空间滤波 , 　速度 , 　气／固两相流 , 　静电传感器 , 　自谱密度