Gas chromatograph 700XA

Dear all,

After replacing the old calibration cylinder with new one,we need to enter the new calibration gas composition into the GC

as the old calibration gas composition still at GC. (RF deviation alarm pop up continuously)  ​

what are the needed steps to add the new values? and how to know the new analysis values are correct?

  • Hashim Ali,
    I understand your question and have also seen the reply from Statik.
    This is a very basic question and as I have no idea of you experience with the GC I can offer the following reply. I assume you have access to the GC via Mon2020.
    As suggested by Statik you need to access the " component data "table .
    In Mon2020 Go : Application >>>component data >>>>in that table update Calibration Concentration.
    Enter the "Calibration concentration' of all the gases as stated in the calibration certificate supplied with the new cylinder.

    However before you even attempt to recalibrate you need to confirm that the original chromatography is sound and have the original factory calibration data to hand
    in order to understand the expected result. DO NOT ATTEMPT TO CALIBRATE unless you are sure the chromatogram from the original calibration is still sound .
    1. You need to validate the current calibration status, confirming that the chromatography is acceptable for a re-calibration
    2. Take note of the Response factors from the original calibration reports . Any new calibration should generate factors close to the original.
    Certainly look to the order .Methane with the smallest factor , followed by N2,CO2, Ethane ,Propane , C4's, C5,s , C6+ with the largest.
    Any major deviation suggests that the analyzer set up is questionable i.e partially measured peaks etc. . In the extreme case where you can see no obvious
    gas chromatograph set up issue , the calibration standard could be in error.

    Please contact your local Rosemount Analytical support team for more detailed information .
  • In reply to hashem ali:

    Hashem Ali,

    You are mostly correct.  However, in step 2 there is not normally a need to do a forced calibration, as the new response factors should be within 10% of the old response factors unless there was something wrong with the old calibration gas, something wrong with the new calibration gas, or something wrong with the measurement.

    If you do need to do a forced calibration, you should only need to do this once and it will pass Normal Calibrations from then on.

    As you are running 700XA and MON2020, I highly recommend that you download the latest version of the MON2020 software ().  Under the Tools menu you will find "Save Diagnostic Data".  Run this and it will save a file that has your configuration, chromatograms, calibration reports, and other information that will help us diagnose any issues.  After the file is created, it will ask you if you want to email it.  Select Yes, and then email it to myself ( and the customer service center ( and we will have someone check it and provide advice if necessary.



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