Abstract: During a method of evaluating a dosing operation, carried out by means of a dosing pump, for dosing a liquid medium in a vessel, filled at least partially with a gas, a pressure profile of the gas, present in the vessel, is detected at least periodically during the dosing operation. This pressure profile is compared with a desired value profile, prescribed for a control unit of the dosing pump, of the pump rate or pump output defining the dosing operation, and an evaluation result is issued in dependence on the comparison. In such case, the dosing operation is evaluated to be faulty or in need of correction when it is determined that the detected pressure profile over time with the prescribed pump rate or prescribed pump output lies outside a desired value range. A plurality of error conditions for the evaluation of the dosing operation are used, which consider the pressure development in a time window after a prescribed change in the defining pump rate or pump output.

Abstract: “A positioning device is provided for positioning pipettes in medical-technical applications including at least one pipetting apparatus with at least one pipette as well as several drive units for positioning a pipette tip and for moving it over a working area and transversely to a working area, a sliding carriage that is moveable transversely to the working area supports the pipette, at least one pump drive with at least one pump and at least one pump chamber is provided for aspirating or dispensing a medium, such that by providing the at least one pump drive with pump and at least one pump chamber integrated in the sliding carriage that is moveable transversely to the working area, the design of the positioning device becomes compact and precise pipetting is achieved.