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FID Air Flow - HP6890

Posted: Thu May 10, 2012 3:45 pm
by GDstew4
I'm setting up the back detector on this unit for the first time. For the past year we've only used the front, now we're adding a second column. My problem is that I can't get any air flow to the back detector.

Air pressure coming into the lab is 80psi and is sufficient for the front detector to run at 400mL/min. When I try to set the back FID to 360mL/min, nothing happens.

The air lines are split from the same source and I've loosened the fittings in back to confirm that air flow is being provided to the GC. H2 and makeup gas flow works fine to both detectors, it's just the air flow that doesn't turn on.

I can provide a couple pictures if necessary, otherwise I'm at a loss and Agilent only sent me a troubleshooting guide on FID ignition. Thanks in advance for any tips!

Re: FID Air Flow - HP6890

Posted: Thu May 10, 2012 4:08 pm
by chromatographer1
Your needle valve may have failed after being tightened too far, breaking the needle off inside it.

Time to trouble shoot. Trace the flow of air until you find the blockage.

best wishes,

Rod

Re: FID Air Flow - HP6890

Posted: Thu May 10, 2012 6:25 pm
by dblux_
Does your instrument have EPC for FID ?