A needle assembly that includes a hub, a cannula and a retractable sheath. The driving circuit comprises a first thin film transistor structure. The reference value is determined based on length calculated by reading a legitimate paper sheet, a theoretical value of the length in the predetermined area, and a predetermined tolerant value for a legitimate paper sheet. A \u201clever\u201d mechanically links these components. In one embodiment, the floatation module comprises a tubular sleeve having a buoyant material applied thereto. Methods of evaluating and adjusting a liquid coffee concentrate’s furfuryl acetate to 4-ethyl guaiacol ratio value are also disclosed.