Agilent Technologies 6850 Series II User Information page 172

6.
7.
Cool on-column inlet hardware problems
The inlet cools very slowly
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The inlet is unable to reach a temperature setpoint
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The syringe needle bends during injections
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If you are using the GC Automatic Liquid Sampler (GC ALS):
See the GC ALS manual for additional information.
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Released: March 2004
Once the needle has entered the column, release the cooling tower and
continue to insert the needle. Allow 1 to 2 seconds for back pressure on
the duckbill to seal it around the inserted needle.
Start the GC, depress the syringe plunger as quickly as possible, and
withdraw the needle from the inlet.
The inlet fan is not running or is blowing upwards, out of the GC lid. Check
the fan to make sure it is operating. If it is not, contact your Agilent service
representative.
Check the temperature equilibration time. If the equilibration time is too
short, the inlet may oscillate. Increase the equilibration time.
Check that cryogenic cooling is turned off. If you do not turn it off when
not in use, both the inlet and the oven may be unable to reach their
setpoints, particularly temperatures near room temperature. If you turn
the cryogenic cooling off and the inlet still fails to reach the setpoint tem-
perature, contact your Agilent service representative.
The needle may have been defective before the injection was made. Check
each syringe before injection to make sure the needle is straight.
Check that the needle support assembly is installed correctly.
Check that the correct insert is installed and that it is installed correctly.
Check the alignment of the inlet septum and the septum nut.
The inlet septum hole may have closed. Replace the septum.
The sampler vials may be over-crimped.
Check the needle guide for signs of wear or damage. Replace the needle
guide if necessary.
Check the alignment of the inlet and the automatic sampler.
6850 Series II GC User Information
Routine Maintenance: Inlets
Maintaining a cool on-column inlet
page 172 of 256