A system for monitoring the level or amount of a material within a container is provided. A distal end of the barrel defines a roof, and an elongate tip, in fluid communication with the barrel, extends from the roof. This method seeks all no-stationary points or intervals in the audio stream and creates a list of segments. Preloaded struts operate to extend the display rack to its tool accessible and tool visible condition when the retaining force on the display rack is released. The non-overlap time can be programmed in increments of the clock-to-Q delay of a standard memory element. The path may be replaced with a redundant path.