Agilent Technologies 1200 Series Manual page 12

1
Introduction
Overview of the Hydraulic Path
Figure 3
When turned on, the quaternary pump runs through an initialization
procedure to determine the upper dead center of the first plunger. The first
plunger moves slowly upwards into the mechanical stop of chamber and from
there it moves back a predetermined path length. The controller stores this
plunger position in memory. After this initialization the quaternary pump
starts operation with the set parameters. The active inlet valve is opened and
the down-moving plunger draws solvent into the first chamber. At the same
time the second plunger is moving upwards delivering into the system. After a
controller-defined stroke length (depending on the flow rate) the drive motor
is stopped and the active inlet valve is closed. The motor direction is reversed
and moves the first plunger up until it reaches the stored upper limit and at
12
Principle of the Pump
1200 Series Quarternary Pump User Manual