Method of selecting pipetting parameters for aspiration and dispense of a liquid sample using a pipetting device comprising: (i) a fluid chamber, in which a substantially continuous fluid column is disposed; (ii) a measuring chamber with a pressure transducer, whereby the measuring chamber is connected pneumatically to the fluid chamber; (iii) a pump connected to the fluid chamber, the pump comprising a piston for moving the fluid column disposed in the fluid chamber and for generating negative pressure or positive pressure in the fluid chamber for aspirating or dispensing liquid samples; (iv) a pipette tip connected to the fluid chamber for drawing in or dispensing liquid samples; and (v) a computer for processing measuring signals sensed by the pressure transducer; and whereby the method is characterized by comprising the following steps: (a) starting to measure the pressure in the fluid chamber as pressure in the measuring chamber, monitoring said pressure in the measuring chamber with the pressure transducer, and processing the measuring signals of the pressure transducer by the computer; (b) immersing the pipette tip into a liquid from which a liquid sample should be drawn in; (c) releasing an unidirectional impulse to the fluid column disposed in the fluid chamber by moving the piston of the pump of the pipetting device at the beginning of aspiration of the liquid sample, wherein the unidirectional impulse is setting the fluid column disposed in the fluid chamber into oscillations in relation to the liquid, the oscillations being characteristic for the drawn-in liquid sample; (d) monitoring the characteristic oscillation behavior of the fluid column as pressure oscillations in the measuring chamber using the pressure transducer, and processing by the computer the measuring signals produced by the pressure transducer and corresponding to the pressure oscillations in the measuring chamber; (e) monitoring by the computer the further progression of the pressure in the fluid chamber during aspiration as pressure progression in the measuring chamber and processing the measuring signals that are produced by the pressure transducer and that are corresponding to the pressure progression in the measuring chamber; (f) reproducing the measuring signals, monitored and processed in the steps (a), (d), and (e) by the computer, as typical pressure curve that reflects the pressure in the fluid chamber after immersion of the pipette tip, that reflects the characteristic oscillation behavior of the fluid column influenced by the aspirated liquid sample, and that reflects the further progression of the pressure in the fluid chamber during aspiration; and (g) comparing the typical pressure curve for aspired liquid samples reproduced in step (f) to known, correspondently gained and characteristic pressure curves (9',9") of known liquids. (i) a fluid chamber, in which a substantially continuous fluid column is disposed; (ii) a measuring chamber with a pressure transducer, whereby the measuring chamber is connected pneumatically to the fluid chamber; (iii) a pump connected to the fluid chamber, the pump comprising a piston for moving the fluid column disposed in the fluid chamber and for generating negative pressure or positive pressure in the fluid chamber for aspirating or dispensing liquid samples; (iv) a pipette tip connected to the fluid chamber for drawing in or dispensing liquid samples; and (v) a computer for processing measuring signals sensed by the pressure transducer; (a) starting to measure the pressure in the fluid chamber as pressure in the measuring chamber, monitoring said pressure in the measuring chamber with the pressure transducer, and processing the measuring signals of the pressure transducer by the computer; (b) immersing the pipette tip into a liquid from which a liquid sample should be drawn in; (c) releasing an unidirectional impulse to the fluid column disposed in the fluid chamber by moving the piston of the pump of the pipetting device at the beginning of aspiration of the liquid sample, wherein the unidirectional impulse is setting the fluid column disposed in the fluid chamber into oscillations in relation to the liquid, the oscillations being characteristic for the drawn-in liquid sample; (d) monitoring the characteristic oscillation behavior of the fluid column as pressure oscillations in the measuring chamber using the pressure transducer, and processing by the computer the measuring signals produced by the pressure transducer and corresponding to the pressure oscillations in the measuring chamber; (e) monitoring by the computer the further progression of the pressure in the fluid chamber during aspiration as pressure progression in the measuring chamber and processing the measuring signals that are produced by the pressure transducer and that are corresponding to the pressure progression in the measuring chamber; (f) reproducing the measuring signals, monitored and processed in the steps (a), (d), and (e) by the computer, as typical pressure curve that reflects the pressure in the fluid chamber after immersion of the pipette tip, that reflects the characteristic oscillation behavior of the fluid column influenced by the aspirated liquid sample, and that reflects the further progression of the pressure in the fluid chamber during aspiration; and (g) comparing the typical pressure curve for aspired liquid samples reproduced in step (f) to known, correspondently gained and characteristic pressure curves (9',9") of known liquids.