Coaxial cavity for measuring level of liquid in a container

摘要

A method and means for measuring the level of a liquid in a container. A coaxial cavity having a perforated outer conductor is partially submerged in the liquid in the container wherein the liquid enters and terminates the annular region of the coaxial cavity. The fundamental resonant frequency of the portion of the coaxial cavity which does not contain liquid is determined experimentally and is used to calculate the length of the liquid-free portion of the coaxial cavity and thereby the level of liquid in the container.