Method of controlling a pipetting arrangement or of producing liquid product doses
A pipetting arrangement includes at least two sets of pipettes ( 9 a; 9 b; 9 c; 9 d ). Each set of pipettes ( 9 a; 9 b; 9 c; 9 d ) is operationally connected, via a controllable ON/OFF valve ( 11 a; 11 b; 11 e; 11 d ) to a common aspiration port ( 7 ). Latter is connectable to a pumping arrangement. The valves ( 11 a; 11 b; 11 e; 11 d ) are controlled by a timing-control unit ( 15 ) conceived to establish, by control of the valves ( 11 a; 11 b; 11 e; 11 d ), the operational connections of the at least two sets of pipettes ( 9 a; 9 b; 9 c; 9 d ) to the aspiration port ( 7 ) in a time-multiplexed manner.
1. A method of controlling a pipetting arrangement or of producing at least two liquid doses of predetermined volumes, comprising:
applying a first of at least two sets of pipettes to a first reservoir for a first liquid, operationally connecting said first set of pipettes to a pressure port operationally connected to a pumping arrangement and establishing an ejecting or aspirating effect at said pressure port,
opening a first On/Off valve, and interconnected between said first set of pipettes and said pressure port, thereby aspirating or ejecting a first liquid into or from said first set of pipettes;
closing said first ON/OFF valve and interconnected between said first set of pipettes and said pressure port;
applying a second set of said at least two sets of pipettes to a second reservoir for a second liquid, operationally connecting said second set of pipettes to said pressure port operationally connected to said pumping arrangement and establishing an aspirating effect or an ejecting effect at said pressure port,
opening a second On/Off valve interconnected between said second set of pipettes and said pressure port, thereby aspirating or ejecting a second liquid into or from said second set of pipettes;
closing said second ON/OFF valve interconnected between said second set of pipettes and said pressure port;
thereby time-multiplexing said operational connections subsequently from said first set of pipettes to said second set of pipettes to said pressure port by respectively time-controlled opening of said first and second ON/OFF valves,
said pumping arrangement being controlled to be ongoingly operative during said multiplexing, and
establishing the volumes of said aspirated or ejected doses merely by selecting the time spans during which said valves are respectively open.
2. The method of claim 1 , wherein said pumping arrangement comprises a line network to a pressure station of a building installation.
3. The method of claim 1 comprising time-multiplexing said operational connections directly subsequently from said first set of pipettes to said second set of pipettes.
4. The method of claim 1 , comprising selecting at least one of said at least two sets of pipettes to comprise one single pipette.
5. The method of claim 1 , comprising at least one of:
said first and second liquids being different,
said first and second receptacles being two distinct receptacles,
said applyings being performed simultaneously.
6. The method of claim 1 , further comprising an additional, selectable mode of operation wherein said operational connections of said first and second sets of pipettes to said aspiration port are simultaneously established.