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The example shown below is a constant pressure method.
ACTIVE
METHOD
EDIT
METHOD
CTRL
RUN
TIME
END
TIME
Method 1
Method 1
0.00
20.00
Col Press (psi):10.0 Col Flow (mL/min):2.0
Linear Vel(cm/sec):35 Total Flow (mL/min):25
Split Ratio: OFF
FRONT EFC, TYPE 1 Page 1 of 2
Step
Pressure (psi) Rate (psi/min) Hold (min)
Total (min)
Initial
10.0
-
2.00
2.00
Constant
Column Flow
Type 1 EFC with the CP-1177 will automatically building a pressure program
to keep the column flow rate constant during temperature programming of
the column oven when Constant Flow is selected. Constant Flow is enabled
on page two of the EFC method section. The same general guidelines
should be followed for all injection modes. If the column is operated
isothermally then the pressure should be kept constant. If the column is
temperature programmed then the pressure can either be held constant or
programmed. Programming the injector pressure generally has no significant
impact on chromatography, other than a slight reduction in analysis time. In
some instances resolution may either improve or degrade depending on the
settings. For larger volume hot splitless injections, a technique called
Pressure Pulse is also available for use with Constant Flow programs with
Type 1 EFC. Use the following guide for setting injector pressure and/or
building a pressure program.
Temperature programming the column oven results in an increase in carrier
gas viscosity which results in a decrease in column flow rate. This effect can
be offset by applying the appropriate column pressure program. The second
page of the TYPE 1 EFC allows constant flow mode to be selected. If
Constant Flow Programming is enabled, a pressure program based on the
column parameters and the column oven temperature program will be
automatically built whenever the method is activated. If the desired column
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