User`s guide

4-27
Operation 4
• key in the value for the flow rate, 0, and press
Enter.
• press the Add soft key to add a second timed
event.
• key in the time for the second flow rate, 5, and
press Enter.
• key in the second flow rate, 3, and press Enter.
If you try to enter a flow rate value which is too
high for the pump head, the entry is refused by the
software. The maximum value accepted in a gradi-
ent system is the value of the smallest pump head
size in the system.
If you do not program a flow rate at 0.00 min., the
software will assume the current flow rate for the
time 0.00 min., i.e. for a stopped pump, a flow rate
of 0 mL/min. There will then be a gradient be-
tween 0 mL/min. and the first programmed flow
rate. With this example the flow rate will be as
shown in the opposite figure.
To stop the flow of solvent at the end of a run,
you must program a flow rate of 0 mL/min. Other-
wise, the pump will continue to run with the last
programmed flowrate, even after the last timed
event. If there is more than one pump in the system,
you must program a composition point containing
all of the pumps followed by a flow rate of
0 mL/min.
If the system is set up to do more than one
sample, the initial composition for the
method can be maintained between method
runs by programming this composition at
the end of the program, for example 5% B.
At the end of all the samples, link to an-
other file to completely stop the flow of
liquid. See the opposite figure.
Wait
In this menu you can make the program wait until
Input # 1 is activated. This is used to stop the
program until another piece of equipment is ready,
for example an auto-sampler or a fraction collector.
There are two pieces of data for this menu.
Programming a Method
There will be a linear gradient
between any two programmed
flow rates. With the above
example, the flow rate will
linearly increase from 0.00 mL/
min to 3.0 mL/min in 5.00
minutes.