The presented invention is a system, which may be attached to a face of a container, such as a barrel or a tank, that includes at least one antenna and an electronic system that causes the transmission of one or more signals in at least one frequency range, where the transmitted signals that are reflected off the fluid or liquid contained within the container are collected and evaluated by a method that determines a level of the fluid or liquid within the container based on the received reflections. The system and method further achieves technical advantages over the prior art as the invention disclosed remains external to the enclosed system (barrel, etc.) and does not affect the internal ecosystem or contents of the barrel.