A liquid dispensing system including a renewable source of the liquid, such as a water bottle, in fluid communication with a reservoir contained by a dispensing apparatus such as a water cooler, from which the liquid may be dispensed. An electronic device transmits a transmission-frequency measurement signal for measuring a transmission frequency of data and transmits the data by using a light source which transmits an optical signal. The analogdigital converts an analog measurement signal of the load current into a digital measurement signal of the load current and is actuated or designed in such a way as to carry out a plurality of current measurements per PWM period. Files on the one or more storage devices are identified that meet a selection policy for files required for rapid restoration of the data processing system. The pore may be formed with the use of sidewall spacers. Removing the wetting agent and the stabilizing agent from the membrane.