Expression for calulating RSD in OpenLab 2.7

I'm looking for a couple expressions in the reporting module where it would take the peak area of a certain compound for all the selected injections included iin the report, and then calculate RSD.  In another field, it would compare that RSD against a set value and determine if it was a pass or fail.

  • Hello,

    All injections in the report or just certain types of injections? You could do this as a custom calculation but if you want to do it in the IR reporting that is also possible. Do you need to do it for just the one compound, as it would be just about as easy to do it for all named compounds.

    Marty Adams

  • Hey Martin,

    Just for the selected injections in the report, and only for one compound at the moment.  Once I get a hang for for formula we'll use it for other applications later on.

  • Hello,

    To calculate the RSD and Pass/Fail results, one can try the following:

    In the reporting go to the edtor and open "table properties"

    In my specific case, I want to calculate RSD for Area, so I choose the column  A, pA*s and press "Column Properties"

    In the "Summary Calculations" select "Average", Standard Deviation" and "RSD" checkboxes. For all of this values one can select how many digits after comma it will be rounded.

    In this screen I would also create a "variable" for the RSD with the name "arearsd" you can use your own just remember it.  We we will use it later for "Pass/Fail". After this press OK and OK.

    Press this button.

    And go to Report parameters, and create new propertie by pressing "Add" button and filling Parameter name, Prompt name and Value.

    Parameter name will be used for "Pass/Fail". Value: you can choose later, just put default value. Prompt name is how this propertie will be displayed. After Press OK

    Now from Report Items Drag and Drop Text box from left to your report

    In the First box Type Pass/Fail while in another press right button on the mouse and select "Properties".

    Choose "Value" and "fx" to open Expression Editor".

    Here type the following:

    =IIF(arearsd<RSDarea, "Pass","Fail")

    and press OK.

    Refresh your template. Now you should have this box in the top of your screen. You can change this value here.

    Below you can see the Pass/Fail result and Average, SD and RSD values.

    If I change RSD area to 0.8 I will get Fail result

    Important that report type must be Single sequence summary (data grouped per sequence)

    Below is my version of SW I used

    Hope this was helpful.

    Kind regards,

  • Hello,

    See the link below for a pdf version of a CC file that will do the calculations. In the example, the RSD is calculated for area and RT by sample type, calibration level, and compound. I also show an example for RT RSD for all injections. I also calculate a Pass/Fail from a limit and the previously outlined CCs. You can view the results in DA and also add to reports. 


  • Thanks, I'll play around with this and see how it works!

  • Thanks, I'll play around with these ideas and see how they work!

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