The present invention relates to a method for classifying a liquid ( 1 ) in a known pipetting system for this liquid ( 1 ), the method being characterized in that the changes of a selected, measurable, and physically founded virtual parameter are detected as a data set typical for this liquid ( 1 ); this typical data set of the selected virtual parameter is compared to corresponding data sets of known liquids, and the liquid ( 1 ) is classified on the basis of this comparison. An especially preferred method and a device for classifying a liquid ( 1 ) relate to a device which comprises a fluidchamber ( 2 ), to which a measuring chamber ( 3 ) is connected, whose internal pressure is monitored using a pressure transducer ( 4 ). At least a first part ( 5 ) of this fluid chamber ( 2 ) may be brought into fluid connection with a sample ( 6 ) of this liquid ( 1 ). A preferred device according to the present invention is characterized in that it comprises a pulse unit ( 17 ), using which pressure changes may be generated in an essentially coherent fluid column ( 7 ) situated in the fluid chamber ( 2 ). These pressure changes cause corresponding pressure changes in the measuring chamber (3 ), which is pneumatically connected to the fluid column ( 7 ), which are recorded by the pressure transducer ( 4 ) and converted into measuring signals. The device additionally comprises a computeror microprocessor ( 8 ), using which these measuring signals of the pressure transducer ( 4 ) may be processed and reproduced as a pressure curve ( 9 ), so that the course of this pressure curve ( 9 ) may be compared to the course of known pressure curves ( 9',9 '') and the liquid ( 1 ) may be classified on the basis of this comparison.