Offset Correction

The Offset Correction is a special normalization to a user defined position on the x-axis. All data objects in the current data view will be scaled to match a user defined position in the current active object.

Use the Offset Correction command from the Mathematics menu or select the Offset Correction operation directly from the Mathematics tab to perform this operation. The following options will be displayed in the Mathematics Tab:

Offset Correction algorithm options

The following algorithms are available for performing an offset correction:

• ShiftToOffset - All objects in the current data view will be shifted to the current intensity at the selected x-axis position of the active data object. Consequently, the intensities of all other objects will be increased/decreased by intensity difference at the selected position.

• ScaleToOffset - All objects in the current data view will be scaled to the current intensity at the selected x-axis position of the active data object. Consequently the active object will remain unchanged and the intensities of all other objects will be multiplied by the factor ActiveSpectrumIntensity[x] / OtherSpectrumIntensity[x].
   

Offset Correction example

Take the following set of spectra as an example:

Selecting the offset correction function shows a vertical line indicating the position on the x-axis, where correction takes place. After performing a ShiftToOffset calculation, all spectra will be shifted to match the intensity of the active spectrum at the given position. The user may also enter a destination intensity value to which the spectra will be matched. The result looks like this:

Offset Correction procedure

To perform a correction, please follow the steps below:

1. Open one or more data objects to be normalized.

2. Merge those data objects into one data view.

3. From the Mathematics menu, select the Offset Correction command.

Numeric offset correction

In the Mathematics tab, do the following parameter adjustments:

1. Select the desired offset correction algorithm.

2. Set the X-Value to the desired normalization position on the x-axis.

The data view will be updated automatically! The vertical line will be shifted to the new position automatically.

 

2. Set the Y-Value to the desired intensity or do not modify this parameter if you like to keep current intensity (Optional).

3. Click the Calculate button.

Graphical offset correction

In the data view, do the following:

1. Select the desired offset correction algorithm.

2. Move the mouse pointer close to the vertical line.

3. Hold down the Left Mouse button

4. Move the vertical line to a new destination.

5. Release the Left Mouse button.

Parameters will be updated automatically! Parameters in the Mathematics tab will be updated automatically according to the new x-axis position.

 

5. Set the Y-Value to the desired intensity or do not modify this parameter if you like to keep current intensity (Optional).

6. Click the Calculate button.