【摘要】 在利用超声脉冲回波法测量液位、料位、厚度和河床地形时,通常会遇到杂散反射干扰、邻近物体干扰、电源和电磁干扰等。本文分析了这几种类型干扰的特征及它们与正常界面回波信号的区别,在此基础上提出了程控增益抑制、自动时间衰减抑制、数字滤波和异值剔除几种抑制干扰的方法。更多还原

【Abstract】 In measuring liquid level, powder position, thickness and riverbed topography by ultrasonic pulse echo method, there often exists interference that comes from floating grains, nearby objects, electric power resources and electromagnetic fields. The characteristics of such interference and the differences between that and the normal echo signals are analysed. Then on this basis, several interference control methods, such as. programed gain-restraining, automatic time-attenuation-restraining, digital filtering and false data deleting, are proposed.更多还原