Calibration %Deviation Custom Field

dbenach
dbenach
in Software Products
Hello,
I need help creating a CF  that calculates the %Deviation for my standard injections. Unfortunately, the System Policy is set up to calculate %Dev based on the Calc. Value in the denominator and I don't have permissions to change the policy. I need to calculate (|Calc. Value - X Value|)*100/(X Value). Thank you.

Answers

  • Jovvor
    Jovvor
    You will need few custom fields to perform this.
    First you need to calculate your "Calc. Value" as you cannot use this field in custom field calculations.
    For this to work you need to create a custom field to calculate your mean Area (or response, height, where you quantify on).

    Create a custom field for that for example: S%.%..AVE(Area) and label your standards starting with S. (e.g. S01,S02 etc.)
    Now you have the average for the standards as a custom field: AVE_Standard_response

    Create a custom field for your standards to calculate your Calc. Value
    Amount*Area/AVE_Standard_response where area can be changed to your response or height or...
    Name Stnd_Calc_Value

    From that you can create your custom field.
    (Stnd_Calc_Value - Amount)*100/Amount
    Name Stnd_Perc_Deviation

    From that you can create a custom field for the standard deviation
    S%.%..STDEV(Stnd_Perc_Deviation)

    I haven't tested it but i think it should work.
    If you need more ellaboration on the custom fields just ask, or if it does not work.
    Set all the custom fields to standards only to not have mismatch with other injections.
  • dbenach
    dbenach
    Hello Jovvor. Thank you for your reply. If I understand your calculation, it would apply if I am making replicate injections of the same standard concentration. I should have mentioned that I am making 7 standard injections at different concentration levels. I may have to create a CF that calculates Calc. Value from the calibration curve equation. Unfortunately, it's a quadratic fit. 
  • Jovvor
    Jovvor
    Hey dbenach,
    that indeed makes it harder. I do not have experience with quadratic fit.
    If you find a way of making it work let me know, I am curious about it.
    Or maybe someone else might help you on the way.

    Maybe in the review field of your calibration curve, the solution you are searching for is listed somewhere in the table. (show all fields in the table)
    Good luck :)

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