• State Verified Answer
  • Replies 9 replies
  • Subscribers 96 subscribers
  • Views 1330 views
  • Users 0 members are here
Related

Agilent Knowledge Portal

Find maintenance, best practice, and troubleshooting articles.

Agilent Knowledge Portal

GC ignition fault during sample analysis.

matt99

Hi,

 

Have this issue with an Agilent 6850 GC:

 

The system performs normally during the pre-run: the oven temperature, front inlet total flow/inlet pressure and signal 1 valve values are all normal/stable.  When we switch to the test method and start sample analysis, we have the following errors:

 

Detector H2 Flow

Detector Air Flow

 

It tries to ignite several times, dropping in and out of ready status before failing with fault 214.  When we switch back to the pre-run, it ignites and behaves normally.  We've checked for leaks although these seem unlikely given that it performs normally on the pre-run.

 

Does anyone have any ideas what might be causing this problem?

 

Thanks.

  • 0 in reply to mr.white

    Hi - yes, the test method blows out the flame.

     

    I had some additional advice from the Agilent service centre in the UK which is similar to yours in your last message.  They advised leaving the gas/air on and changing the make up setting to zero - if the actual reading was then greater than zero, this might indicate an issue with the jet.  I tried this and the actual make up reading was zero as expected.  They also advised that if my lit offset was 2.0, try adjusting to 1.5.  Am just trying this now and the method is working so far.  Am due to leave the lab soon but will add any updates tomorrow.  Thanks very much for your advice today.

  • 0 in reply to mr.white

    Have been running the system all day and the adjustment to the lit offset value has resolved the fault.

     

    I don't have a definitive cause for why the system should be happy with 2.0 for the past 11 years but not now.  We use a hydrogen generator and a zero grade air generator to supply the GC: each are serviced at 6 month intervals with the last service 2 weeks ago.  The only factor I can think of is that the generators are running well and the gas/air is unusually pure: I understand that an offset value of less that the default 2.0 might be required if you're using high purity gases.  However, if the value is too low, the detector may never try to re-ignite.

     

    Thanks for the feedback.

Was this helpful?
Privacy Statement
Terms of Use
Contact Us
Site Help