Programming Column Pressure Or Flow; Advantages Of The Optional Backflush Wizard - Agilent Technologies 7820A Advanced User's Manual

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Columns and Oven

Programming column pressure or flow

Advantages of the optional Backflush Wizard

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When a flow or pressure program is running, the Pressure, Flow,
and Velocity lines that you used to set constant conditions show
the progress of the program.
The oven program determines the length of the run. If a flow or
pressure program ends before the analytical run does, the flow
(or pressure) remains at the last final value.
Press [Col #] then enter the column number.
1
Scroll to Initial pressure (or Initial flow). Type the desired value
2
and press [Enter].
Similarly, enter a value for Initial time. This completes the
3
initial part of the program.
To begin a ramp, enter a positive value for Rate 1. It does not
4
matter whether you are programming up or down—the rate
is always positive.
If Rate 1 is zero, the program ends here. If you enter any
5
other value, the Final value lines for the first ramp appear
and the cursor moves to the line.
Enter values for Final pressure 1 (or Final flow 1) and Final
6
time 1. This completes the first ramp.
To enter a second ramp, scroll to the appropriate Rate line
7
and repeat steps 5
entered.
The procedures below provide simple ways to create the
backflush program. However, for best results, use the optional
Backflush Wizard. The wizard provides the following
advantages:
• Helps you select the best technique for your setup.
• Helps you validate the hardware's capabilities for
backflushing.
• Helps you create relevant baseline data (pre-backflush).
• Helps you validate that the backflushing worked (unwanted
peaks are completely removed from the columns, while
wanted peaks elute normally) by performing runs at various
stages and analyzing the data.
• Helps you adjust the method, if needed, until the
backflushing succeeds.
and 6. A maximum of 3 ramps can be
Advanced User Guide