4
•
Operation
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Solvent Monitor
Installation Guide
4.2
Operating Principle
The solvent monitor accurately measures the real-time consumption of
each solvent and accumulation of HPLC waste using hydrostatic
pressure.
Initially, the solvent monitor measures the ambient pressure and then
forces a small volume of air out of each activated channel port to
determine the hydrostatic pressure at the bottom of the solvent
reservoir/waste container. These measurements are performed
throughout solvent consumption improving the volume estimation
accuracy. The solvent monitor continuously self-calibrates with respect
to the used solvent and solvent reservoir/waste container size.
4.3
Notes on the Solvent Monitor Operation
TIP
Although this section states solvent reservoirs, it also applies to
waste containers, if not stated otherwise.
System safety
If the error limit is reached, Chromeleon will perform the following:
•
Complete the current injection
•
Abort the queue
•
Perform an emergency program (if defined)
However, the solvent monitor will not prevent the system from running
dry. Therefore, you need to define an emergency method in the
Chromeleon software to stop the pump flow and/or additional
emergency steps.
Calibration and accuracy
Very first power up
After the solvent monitor has powered up, the channel status indicator
flashes green while the solvent monitor performs the first pressure
measurement. Upon this measurement, a first volume estimation based
on the entered solvent reservoir size is shown. This first estimation is
inaccurate, typically ± 15%.
The solvent monitor continues to acquire calibration data. After the
system has consumed 5% of the solvent reservoir volume, an accuracy
of about 10% is obtained and improved further during the process.
