User guide

194 Advanced User Guide
8 Inlets
If a column in the flow path is not defined
1 Press [Front Inlet].
2 Set the inlet temperature (Initial temperature) and any desired
ramps.
3 Set other parameters as described for a defined column.
4 Set Total flow into the inlet. Measure flows out of the split
vent and septum purge vent using a flow meter.
5 Subtract the septum purge flow and split vent flow from Total
flow to get column flow.
6 Calculate the split ratio (split vent flow/column flow). Adjust
as needed
MMI splitless and pulsed splitless modes
In these modes—with or without a pressure pulse—the split vent
valve is closed during injection and vaporization of the sample
and stays so while the sample transfers to the column.
At a specified time after injection, the valve opens to sweep
vapors left in the liner out the split vent. This avoids solvent
tailing due to the large inlet volume and small column flow rate.
Stage 1. Sample injection
With the split vent valve closed, the sample and solvent transfer
to the column.