An electronic device digitally combines a single voice input with each of a series of noise samples. The valve arrangement is suitable for use with a rotary peristaltic pump and is capable of allowing flow of fluid in a first direction and capable of preventing flow of fluid in a second direction, wherein the valve arrangement comprises a valve having a cracking pressure of about 0. By judging this flag by using an image handling apparatus of an image processing system, only valid order files are processed. Furthermore, each flash memory device includes an internal buffer for accelerating the block management operations. The sensor unit and its electronics lack galvanic connection with electrically conductive components in the main unit, transfer of measurement signals between both of the units taking place by optical energy transfer, capacitative or inductive transfer.