A diffusion device for atomizing liquids includes a floating magnet disposed within a track inside at least one package with liquid for the atomizing diffusion device, wherein as a liquid level inside the package changes, the floating magnet moves substantially vertically along the track, a plurality of Hall effect sensors or Hall effect switches disposed outside the liquid at various positions, the Hall effect sensors or Hall effect switches each generating an output voltage in response to a magnetic field of the floating magnet, and a processor that receives the output voltages and fits them to a model that includes the floating magnet position with respect to various sets of output voltages to determine a position of the floating magnet with respect to the Hall effect sensors.
