Systems and methods for reading RFID tags using joint beamforming and preamble detection in accordance with embodiments of the invention are disclosed. A double-layered non-magnetic ground layer consists of a pure chromium layer, positioned closer to a substrate, and a chromium-molybdenum-tungsten ternary alloy layer, positioned closer to a magnetic recording layer. Still further, the system includes a circuit for selecting a best fit implant size and position from all of the fit calculations. The first blade wheel with first fan blades and the second blade wheel with second fan blades are disposed in the flow passage next to the support for being driven by the driving device. The functional region part preferably comprises a plurality of conductive path-forming parts each extending in the thickness-wise direction of the sheet and arranged in a state insulated from one another by insulating parts. The controller converts the measured difference into a value corresponding to a volume of the liquid in the keg.