Agilent 7890 GC: PGM-File - Entering Pressure or Flow Input?

Commands and Tips for Third-Party Devices
Agilent 7890 GC: PGM File - Entering Pressure or Flow?

Depending on the inlet (or auxiliary device), you have to define pressure or flow in the PGM file. In addition, this depends on the column dimensions. The GC can calculate the flow from the pressure (or vice versa) only if the column diameter and the column length are known. In all other cases, you have to enter the values required by the inlet or auxiliary device.

Whether the pressure or the flow must be entered also depends on the control mode to be used by the GC for the separation. The following control modes are available:

Constant flow
Constant pressure
Flow ramp
Pressure ramp

Known column dimensions

Inlet/AUX	Con. Pressure	Con. Flow	Press. Ramp	Flow Ramp
Cool On - Column	Pressure	Flow	Pressure	Flow
Split/Splitless	Pressure	Flow	Pressure	Flow

Unknown column dimensions

Inlet/AUX	Con. Pressure	Con. Flow	Press. Ramp	Flow Ramp
Cool On Column (with EPC)	Pressure	-	Pressure	-
Split/Splitless (with EPC)	Pressure	-	Pressure	-

Tips:

If you want to work with a constant flow but if you do not know the column dimensions, you have to enter pressure instead of the flow nevertheless, e.g., for Cool-On-Column-Inlet. In this case, you have to determine the pressure by trial and error to achieve the desired flow.

For installation instructions for the GC, refer to Hardware Installation: Agilent 7890 GC: Installation.