Theory of Calibration
Using the Calibration Curve

If you know the calibration coefficients, you can calculate the amount value for any area value by inserting the coefficients in the formula of the respective calibration type.

Within the range of the curve covered by the calibration points, it is possible to convert any peak area into the corresponding amount (see the example below).

Standard Sample

Enters the amounts (x1 to x4) of the different standard samples and determine the Calibration Function by selecting the calibration type (here: linear with offset). Depending on the selected integration type, area values (F1 - F4) are established from the detected peaks. One area and one substance amount value form one calibration point. The positions of the calibration points determine the curve that Chromeleon calculates with an approximate method. The final course of the calibration curve is determined by the calibration coefficients (here: c0, c1).

Unknown Sample (Analysis Sample)

For an unknown sample, the previously calculated calibration coefficient and one or several area values are known. The area value is a known parameter and is on the x-axis. This means that the two axes are interchanged in the diagram. As a result, the calibration function must be converted in its inverse function. Chromeleon performs this, also. You can now calculate the amount by inserting the calibration coefficients and area values.

Alternative ways of calculating the calibration curve include the exclusion of outliers, the different weighting of calibration points, and the formation of "averaged" calibration points from one calibration level.