User guide

165
Agilent 7890A Gas Chromatograph
Advanced User Guide
Agilent Technologies
8
Inlets
Using Hydrogen 167
Inlet Overview 168
Carrier Gas Flow Rates 169
About Gas Saver 170
Pre Run and Prep Run 171
Auto Prep Run 172
About Heaters 173
About the Split/Splitless Inlet 175
Split/Splitless inlet split mode overview 176
Split/Splitless inlet splitless mode overview 177
The S/SL inlet pulsed split and splitless modes 178
Split/Splitless inlet split mode minimum operating pressures 179
Selecting the correct S/SL inlet liner 180
Vapor Volume Calculator 182
Selecting parameters for the S/SL splitless mode 183
About the Multimode Inlet 186
Septum tightening (MMI) 186
Heating the MMI 187
Cooling the MMI 187
MMI split mode minimum operating pressures 188
Selecting the correct MMI liner 189
Vapor Volume Calculator 191
MMI split and pulsed split modes 191
MMI splitless and pulsed splitless modes 194
MMI solvent vent mode 201
MMI Direct Mode 209
To develop a MMI method that uses large volume injection 210
Multiple injections with the MMI 213
About the Cool On-Column Inlet 222
Retention gaps 223
COC inlet temperature control 223
Setting COC inlet flows/pressures 224
About the PTV Inlet 226
PTV sampling heads 226
Heating the PTV inlet 227