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Contents
Chapter 1 About This Manual
Manual Overview ....................................................................................................... 2
Intended User ............................................................................................................ 3
Conventions ............................................................................................................... 3
Chapter 2 Introduction to Headspace and to the
7694 Headspace Sampler
Overview of Headspace Analysis ............................................................................ 6
The 7694 Headspace Sampler .................................................................................. 7
Oven (G1289/G1290) ......................................................................................... 7
Heated Zones (G1883) ...................................................................................... 8
Vial Tray (G1289/G1290) ................................................................................... 9
Vial Transport Arm (G1289/G1290) ................................................................. 9
Sampling System ............................................................................................. 10
Transfer Line .................................................................................................... 10
Keypad and Display ......................................................................................... 10
Pneumatics ....................................................................................................... 11
Principles of Operation ........................................................................................... 13
General Operation ........................................................................................... 13
Power on Diagnostics ..................................................................................... 14
Standby Condition ........................................................................................... 14
Vial Pressurization ........................................................................................... 15
Filling the Sample Loop .................................................................................. 16
Loop Equilibration ........................................................................................... 17
Injecting the Sample ........................................................................................ 17
End of Cycle and Vial Recovery .................................................................... 18
Modes of Operation ................................................................................................. 19
Standard Headspace Extraction .................................................................... 19
Multiple Headspace Extraction with Multiple Vial Puncture–
G1289/G1290 only ............................................................................................ 21
Multiple Vial Puncture with Constant Heating Time–G1289/G1290 only . 22
Multiple Headspace Extraction with Single Vial Puncture ........................ 23
Multiple Headspace Extraction for Analyte Concentration–
G1289/G1290 only ............................................................................................ 23