User guide

Inlets 8
Advanced User Guide 171
Pre Run and Prep Run
With some inlets and operating modes, certain instrument
setpoints are different between runs than during an analysis. To
restore the setpoints for injection, you must place the GC into
the Pre Run state.
You must use the Pre Run state when:
• Using gas saver with any inlet.
• Using splitless mode with any inlet.
• Using a pressure pulse mode with any inlet.
• Using the solvent vent mode of the PTV inlet.
• Using the direct or splitless mode of the Volatiles Interface.
There are three ways to begin Pre Run—manually (press [Prep
Run] before each run), automatically (for Agilent samplers), or
using Auto Prep Run (for non- Agilent samplers). The three
methods are discussed below.
During the Pre Run state:
• The Pre Run light blinks and Not Ready is on.
• Setpoints change to the correct values for injection.
• Inlet, detector, and oven equilibration times begin.
When all equilibration times expire, the Pre Run light is on
steadily. When all criteria for a run are met, the Not Ready light
turns off. The GC is now ready for sample injection.
The [Prep Run] key
Press [Prep Run] before you inject a sample manually. The GC
enters the Pre Run state. When the Pre Run light is steady and
the Not Ready light goes off, begin the analysis.
Agilent samplers
If you are using an Agilent automatic sampling system, the
[Prep Run] function is automatic.
Start the sampler. It generates the [Prep Run] function, When all
the setpoints are reached and the GC becomes Ready, sample
injection begins.