Metrohm 840 PC Control 5.0 / Touch Control User Manual
Page 288
4.10 Dosing and liquid handling
276
PC Control / Touch Control
Example:
1 L reagent has to be dosed within 1 hour with a 50 mL exchange
unit. What is the dosing rate?
Total duration = 60 min
Volume
= 1000 mL
Filling time
= 24 s (at max. filling rate)
Cylinder volume = 50 mL
Number of refills =
20
50
1000
volume
Cylinder
Volume
=
=
If the division delivers an integer number, the last filling is no longer
a refilling and must be deducted. In our example, 19 refills are nec-
essary. There is no dosing during this time i.e. the net dosing time is
3600 s – 19 ⋅ 24 s = 3144 s = 52.4 min
The dosing rate is thus
1000 mL / 52.4 min = 19.1 mL/min
Summary in a formula:
Dosing rate in mL/min:
1
.
19
60
1
24
19
60
1000
60
1
time
Filling
refills
of
No.
duration
Total
Volume
=
⋅
⋅
−
=
⋅
⋅
−
=
Parameterization:
• Volume: Volume to be added.
• Dosing rate: Rate at which the volume is added. The maximum
dosing rate depends on the cylinder volume of the exchange or
dosing unit used (see Section 3.8.6).
• Dosing time: Time while the reagent is being dosed i.e. the filling
time is not taken into account.
• Temperature: Manually entered dosing temperature. If a tempera-
ture sensor is connected and temperature measurement is set to
automatic
or continuous under Sensor (see Section 4.1.5) then the