How To Optimize The Compressibility Compensation Setting; Solvent Compressibility Calibration - Agilent Technologies 1260 Infinity II User Manual

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Optimizing Performance

How to Optimize the Compressibility Compensation Setting

How to Optimize the Compressibility Compensation Setting

When a solvent is metered at ambient pressure and compressed to a higher
pressure, the volume decreases depending on its compressibility. Solvent
compressibility is a non-linear function of pressure and temperature. It is
specific for each solvent.
In order to deliver the desired flow accurately at all pressures, Agilent pumps
use a compressibility compensation. For standard LC applications, e.g. using a
400 bar binary pump, an average compressibility value for the solvent is
sufficient.
For the 600 bar 1260 Infinity II Binary Pump , the pressure-dependency of a
solvent compressibility needs to be considered. It is determined at different
pressures between 0 – 600 bar. The pump uses the obtained non-linear
function to select the correct compressibility value for the actual pump
pressure. Compressibility data for the most common solvents is readily
available in the pump firmware.
The compensation algorithm is so powerful that the damper and mixer can be
removed from the pump flow path at low flow rate while the pressure ripple
and composition ripple remain at low levels.
For method compatibility reasons, the legacy compressibility compensation is
still available.

Solvent Compressibility Calibration

Unlisted or premixed solvents can be calibrated with the Solvent
Compressibility Calibration function. For a detailed description, see
Pump Solvent Compressibility Calibration"
66 InfinityLab LC Series 1260 Infinity II Binary Pump User Manual
on page 103.
"Binary