| 摘要 |
The invention relates to a pipetting device (10) for pipetting dosing liquids (32), comprising a pipetting channel (12) extending along a channel path (K), in which a piston (14) designed as a solid body is movably accommodated along the channel path (K) in order to alter, by way of movement along the channel path (K), the pressure of a working gas (34) that wets the piston (14) on a dosing side (14a) facing the dosing liquid. The pipetting device (10) further comprises a motion drive (20) for the piston (14), by means of which the piston (14) can be driven to a movement along the channel path (K). The pipetting device (10) also comprises a control unit (24) for controlling the motion drive (20). According to the invention, for pipetting a predetermined single dosing volume (36) of less than 5 µl, the control unit (24) is configured to operate the motion drive (20) such that the piston (14) is moved in a pipetting direction (P), and in doing so, the dosing-side end surface (14a) thereof sweeps across a pipetting volume, which is no less than 1.4 times larger than the single dosing volume (36), and subsequently, the piston (14) is moved in a counter pipetting direction (G) that is counter to the pipetting direction (P). In doing so, the dosing-side end surface (14a) thereof sweeps across a counter pipetting volume, wherein between the start of the control signal of the control unit (24) for driving the piston (14) in a pipetting direction (P), and the end of the control signal for driving the piston (14) in a counter pipetting direction (G), no more than 50 ms (milliseconds), preferably no more than 30 ms elapse. |
