Maintaining The Inlet; Changing Septa - Agilent Technologies 7673 Operating Manual

Preparing for Operation

Maintaining the inlet

Caution
Do not operate the injector without a syringe in place because the syringe latch
may interfere with the motor if it is allowed to swing freely.
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Maintaining the inlet
This section contains inlet information to help you maintain good chemical
performance from your GC.

Changing septa

The average life of an inlet septum should be 200 injections. This is influenced
by the alignment of the injector bracket, the syringe, and the type of septum.
When you replace the septum:
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Caution
Do not tighten the septum retainer nut too much. The syringe needle will core
the septum and push out pieces of the septum material into inlet. Septum life is
often reduced to as few as five injections.
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To check the alignment of the syringe needle to ensure an average septum
life of 200 injections, follow these instructions:
Pull down the syringe carriage until the needle tip is near the top of the
inlet septum nut. The needle should be centered exactly over the hole in
the septum retainer nut. Use a small light to see that the needle will hit the
septum without rubbing on the nut.
If it is not centered, check that the syringe is installed correctly in the
syringe carriage, the syringe needle is straight, and the mounting bracket is
aligned with the inlet.
Clean off the metal surfaces that create the seal.
Replace with the correct septum.
Make sure the bottom of the septum is flat against the base.
For packed and split/splitless inlets, tighten the septum retainer nut only
until the split ring begins to turn on the top of the nut.