Back Inlet pressure not Ready

Hi All

I am coming across a problem when i put a sequence of run, after the run starts when the syringe goes to wash vials it looks fine and after that sample wash looks fine, and when it comes to sample vial again to pick the sample, it stays there for long and i am getting the below message.  Some times it will pick after 5 min some time it will take longer.  Is there a leak

For 5 min or some times even longer it is staying there, after that it runs normal, but by displaying the same message again while it is in run. 

I have attached the pressure setting an it is in constant flow,

I.  I tried changing the inlet, gold seal, check the coloumn end both inlet and detector end

2. The engineer changed the EPC, still i am getting this message.  I tried it with gas saver mode off as well. Any sugesiton please

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  • What you describe with the washes happening, but a delay when pulling up the actual sample for injection sounds like something about the GC is not in a ready state and the GC is waiting for a part of the GC to become ready.  In this case you describe it is the back inlet pressure.

    However the picture is of the back inlet pressure not ready message, but the GC is already 0.39 minutes into a run.  Now eyeballing your oven ramp rate, it looks like at 0.39 minutes you are still isothermal at 50 C, but when the GC oven starts to ramp inlet pressure often go into not ready states because they are constantly changing the pressure setting in constant flow mode to match the oven ramp.

    Do you have any screenshots of the status screen when in the "preparing for injection" mode?  Is something else not ready when the inlet is not, such as the oven?  I ask, because the inlet pressure is influenced by the oven temperature when in constant flow mode.  So if the oven isn't stabilized the inlet won't be either.

    Flow rates of 6.5 mL/min is okay for FIDs.  That is the standard flow rate for the FID checkout method when GCs are installed.

  • Hi Woody   Sorry for the delayed response, My method is 21.13 min long, 

     

    Rate °C/min

    Value °C/min

    Hold Time min

    Run Time min

    Initial

     

    50

    0.5

    0.5

    Ramp 1

    20

    225

    0

    9.25

    Ramp 2

    40

    300

    10

    21.25

    Additional info, Gas saver mode on at about 2 min, pressure set point at Back inlet is 23 psi, with constant flow mode.

    What you describe with the washes happening, but a delay when pulling up the actual sample for injection sounds like something about the GC is not in a ready state and the GC is waiting for a part of the GC to become ready. " Yes you are right it happens in pre run stage.  I have sent you 3 screen shots, if that of any help,

    Prerun screen shot,

    Ready to Inject mode,

    Injecting mode

    What i noticed is when it goes to ready to injection mode (just before the injection) the pressure flow shoots up to 139.4 (which is what i set after the injection) , hence getting this message, in a fraction of second the display disappeared and injection is happening as usual.  This method was created by my senior who is not here anymore and i have been using this for past 3 years.  It never happened before.  My only worry is the fraction of second is increasing in due course to a min and more than 20 min this is what happened last time hence called the engineer, i feel still it persist.  I don't want to end up like before, hence investigating it.  Any help will be much appreciated.  Leaks checked with leak detector by the engineer, EPC changed, split vent trap changed.

    Kind Regards

    Revathy

  • Added note, Sometimes once the run starts also i am seeing Black inlet flow not ready message for a short period of time and it will disappear

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