User manual

74 1260 Nanoflow Pump User Manual
5 Optimizing Performance
How to Choose the Primary Flow
How to Choose the Primary Flow
The primary flow can be set in three ranges:
• The default range
The default range is the best compromise between performance and solvent
consumption.
• The low solvent consumption range
The low solvent consumption range, is recommended for long shallow
gradient runs (e.g. peptide maps) or isocratic operation. This mode is not
suitable for fast changes in solvent composition due to the longer gradient
delay. During step gradients at the end of the run the flow control may start
to oscillate for a short time.
• The fast gradient range
This range is recommended for running fast gradient (e.g. < 3 min). The
equilibration time is optimized.
Table 18 on page 74 gives approximate primary flow values in function of the
system pressure, and the set primary flow range.
NOTE
The primary flow is strongly dependant on the system pressure and internal volume of the
flow path of the pump which is defined by the type of inline filter, the presence or absence
of the static mixer, and the flow sensor configuration.
Tabl e 18 Primary flow overview for standard pump configuration
0bar
System
pressure
100 bar
System
pressure
200 bar
System
pressure
300 bar
System
pressure
400 bar
System
pressure
Low consumption range 200 225 250 275 300
Default range 500 570 640 710 780
Fast gradient range 800 995 1190 1385 1580
NOTE
In any case the standard configuration is changed, the primary flow could be higher
compared to the values in above table.