User guide

214 Advanced User Guide

8 Inlets

Setting parameters for the inlet in solvent vent mode

Set or configure the following parameters in the data system's

7890A GC method editor.

Syringe size — Verify the syringe size is configured correctly.

The configured syringe size changes the available choices for

injection volume.

Injection volume — Select the injection volume, then enter a

number of injections. The total injection volume will be

displayed.

Multiple Injection Delay — A pause time, in seconds, between

injections. This is added to the minimum hardware cycle time.

Preinjection washes and pumps are performed only before the

first injection of a multiple injection set.

Postinjection washes are performed only after the last injection

in a multiple injection set.

An example

These values were used for a sample with a broad range of

boiling points.

Table 38 General parameters

Name Value

Sample C

to C

hydrocarbons in hexane

Mode Solvent vent

MMI liner Glass wool packed

Injection volume One 10.0 μL injection (25 μL syringe)

Injection speed Fast

Column 30 m x 320 μm x 0.25 μm -5, part

number 19091J-413

Column flow 4 mL/min constant flow

Table 39 Inlet parameters

Name Value Name Value

Initial temp 40 °C Rate 2 (off)

Initial time 0.3 min Pressure 15.6 psig

Rate 1 720 °C/min Vent pressure 0.0 psig