Agilent Technologies 1220 Infinity II LC User Manual page 90

5
Solvent Delivery System Description
Principles of Operation
parameters. The inlet valve is opened and the down-moving plunger draws
solvent into the first chamber. At the same time, the second plunger moves
upwards, delivering into the system. After a controller-defined stroke length
(depending on the flow rate), the drive motor is stopped and the inlet valve is
closed. The motor direction is reversed and moves the first plunger up until it
reaches the stored upper limit and at the same time moves the second plunger
downwards. The sequence then starts again, moving the plungers up and down
between the two limits. During the up movement of the first plunger, the
solvent in the chamber is pushed through the outlet ball valve into the second
chamber. The second plunger draws in half of the volume displaced by the first
plunger and the remaining half volume is directly delivered into the system.
During the drawing stroke of the first plunger, the second plunger delivers the
drawn volume into the system.
For solvent compositions from the solvent bottles A and B, the controller
divides the length of the intake stroke into certain fractions in which the
gradient valve connects the specified solvent channel to the pump input.
90 1220 Infinity II LC System User Manual