Agilent 7820A GC: Back inlet shut down while front inlet bakeout

I'm trying to bake out the front column after inlet maintenance but the pressure of the back inlet cannot reach the set point and continues to shutdown, also resulting in a shutdown of the front inlet.  I've tried manually changing the back inlet pressure set point (i.e., set point was 23 but pressure wouldn't go above 22.3 psi; if I then change the set point to 20, the pressure cannot achieve that set point either).  Any suggestions?  My front column is a DB5-MS UI and the back column is DB-Select 624 UI, with attempting to bake out the front inlet at 250 degrees Celsius.

  • Hi

    First check there is carrier gas in cyliner or it's finished..Then after check for leak..may be septa need to replace..

  • Hello  ,

    Do you still need assistance with this? If you do, please take into consideration the notes below. However, if the issue was resolved, could you please share what the resolution was?

    Along with the suggestions from  , check whether the correct carrier gas type and the correct column lengths are configured on the GC.

    Do you have a bakeout method that you load from the Software? If you do, can you check whether the column dimensions in that method are correct for the back channel, and that the carrier gas type is also correct? Even if the GC itself has the correct configuration, if you send a method with different configurations to the GC, those will be loaded on the GC, and possibly leading to the shutdown.

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