Metrohm 840 PC Control 5.0 / Touch Control - Manual (Page 282)

4.10 Dosing and liquid handling
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PC Control / Touch Control
4.10 Dosing and liquid handling
With the dosing commands you can add a fixed volume in the method
sequence; exchange or dosing units can also be prepared and emptied
automatically. Complex dosing tasks can be carried out comfortably
with the liquid handling commands.
4.10.1 Dosing (ADD)
The ADD command is used to add a preset volume of a solution.
• Volume (d): Volume to be added.
• Dosing rate (d): Rate at which the volume is to be added. The
maximum dosing rate depends on the cylinder volume of the ex-
change or dosing unit used (see Section 3.8.6).
• Filling rate (d): Rate at which the dosing cylinder is refilled after
addition has been carried out. The maximum filling rate depends on
the cylinder volume of the exchange or dosing unit used (see Sec-
tion 3.8.6).
Under Control device you can select the control device (Titrando,
USB Sample Processor etc.) with which the dosing or liquid handling
command is to be carried out. This button will only be shown when
several control devices have been configured under System/Device
manager (see Section 3.10). The device names are always shown in the
selection list.
The parameters for dosing devices and stirrers are described in Sec-
tion 4.1.5. Selection of the direct parameters is described in Sec-
tion 4.1.6.
4.10.2 Liquid handling (LQH)
This command can be used to carry out liquid handling tasks with a
Dosino (type 700 or 800) dosing device. Together with a USB Sample
Processor the versatile possibilities of the Dosino can be used to the full
extent. The four ports of the dosing units for the Dosino can be used as
inlet or outlet ports as defined by the user. This means that not only
simple dosing and filling processes are possible, but complex liquid
handling tasks such as pipetting and sample transfer can be carried
out without any problems. This requires several LQH and automation
commands that are best grouped together in subsequences (see Sec-
tion 4.12.6).
The dosing functions are to be used in such a way that, in addition to
the function, the port at which the function is to be carried out is also
given. This means the dosing unit inlet or outlet to which the valve disk
first moves in order that the required function is carried out. The defini-
tions of the ports is described in Section 6.5.1.