Chromatogram settings at different scales


We need that in the intelligent report the chromatograms appear in scales according to the type of injection.

For example, in the limit solution we need to see the peak of the entire standard (see image) and in the samples we need to expand the scale to see the smallest peaks to quantify impurities (see image).
How can we configure it in the same intelligent report?

We are using Openlab CDS Chemstation C.01.07 SR2 [255].

Thanks a lot! Òscar
  • So in IR, you can edit the chromatogram's signal and can specify formulas for it using the 'All signals in given scale'.  So for example you could set your 'From' to 0 and then have your 'To' set based on a condition.  For example, if you wanted the maximum scale to be 10 when the sample type is 'Sample' and 100 when it's anything else (you could also use multiple conditions, use another field than sample type that identifies the sample differently such as Sample Description, etc.) you could set the expression for the 'To' to =Iif(First(Sample_Type) = 3, 10, 100).  Was that what you were looking for?

  • Hello rclement,

    Thanks for your answer, Yes, that was what I was looking for.


    I will take the opportunity to ask another questions related to this topic:

    - When you write “… (Sample_Type) = 3,…” does 3 refer to “sample”? Does that mean that the blank, calibration and control sample have other numbers?


    - In the conditional you propose, could I change one of the parameters to another conditional to make the scale of the chromatogram depend on the main peak? For example, Iif (First (Sample_Type) = 3, Peak_Height / 4, 100)


    ¡¡A lot of thanks again!!



  • Hi Òscar

    I think that you can do something like that, although I would probably set the "false" value to 0.  I think that would revert to full scale.

    Kind regards


  • According to the default expression for 'Sample Type';

    =Choose(First(Sample_Type )+1 , "Unspecified", "Calibration", "Checkout", "Sample", "Control", "Blank", "Ladder", "SystemSuitability", "CalibrationCheck", "DoubleBlank", "Matrix", "MatrixDup", "MatrixBlank", "TuneCheck", "ResponseCheck", "Spike")

    So Blank would be 5, Calibration 1, and Control 4.

    As for your second question, I'm not sure how to specify the maximum peak in the chromatogram within an expression.  It doesn't seem to be an available built-in field.  I would be interested if someone has a way to do this though.

  • To all,

    You should have the RTEConceptsGuide as part of your Chemstation install. It has all the enumerations for Chemstation fields listed in the appendix. Also in this document on page 73-75 you will find some useful information on scaling chromatograms to specific peaks.


  • Ah yes, I see that here, you could use the Compound_Name;

    but what about if the largest peak changed from chromatogram to chromatogram; are you able to use the "highest peak" within an expression?

  • I cannot say this will work for all versions of IR but for the latest CDS 2.5 and C.01.10 it will work. In the example, the signal max would 1.2 times the biggest peak. In the example, I also filtered out unknown peaks so you can see in the B channel it scales on the largest named peak not the largest peak overall. 

Was this helpful?