User`s guide

4-26
Operation 4
The percentage of solvent A is calculated as:
% solvent A = 100 - % B - %C.
The example opposite is for a binary gradient.
At 0 minutes, there is 95% solvent A and 5%
solvent B. At 5 minutes, there is 80% solvent A
and 20% solvent B.
Example: 0.00 min 5%B (%A = 95%)
5.00 min 20%B (%A = 80%)
To program the example:
• press the Mixt soft key.
• key in the time for the first composition point,
0.00, and press Enter.
• key in the value for the %B, 5, and press Enter.
• press the Add soft key to add a second timed
event to the program.
• key in the time for the second composition point,
5.00, and press Enter.
• key in the value for the %B, 20, and press Enter.
Composition parameters can be set down to 0.1%
increments. If you key in a value which is too high
(sum A+B+C>100%) the last entry will not be
accepted by the software and you must key in the
last value again, or correct your composition speci-
fication.
Flow
In this menu, you can set the flow rate, for example,
2 mL/min. There are two parameters to specify for
this menu.
- Time at which flow rate occurs.
- Flow rate in mL/min.
Example: 0.00 min 0.00 mL/min
5.00 min 3.0 mL/min
To program this example:
• press the Add soft key.
• press the Flow soft key.
• key in the time for the first flow rate, 0.00, and
press Enter.
Programming a Method
There will be a linear gradient
between two solvent composi-
tion points. With the example
given, the %B will increase
linearly from 5% to 20% in 5
minutes. If you change the
gradient point during a run, the
new gradient will be between
the next programmed gradient
value and the value which
existed at the instant the
gradient was modified.
If you do not program a
composition at 0.00 min., the
pump assumes the current
composition. For a stopped
pump, this will be 100% A.
There will then be a gradient
between 100% A and the first
programmed solvent composi-
tion point. Programming the
example above will give a
composition gradient as shown
in Figure.