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If your data does something odd at one end of the scan, the easiest solution might be to simply trim it away. The truncation dialog below allows you to chop data before or after a selected value.
The truncation dialog.
The menu is used to tell ATHENA whether points should be trimmed from before or after the selected point. The point can be chosen by typing in the box or by clicking the pluck button then clicking on the plot.
Tin oxide data with some spurious points near the end of the scan.
When you select a point, it is indicated with a vertical line, as shown in the plot above. To remove the data before or after that line, click the “Truncate data” button.
Sometimes the issue is not simply that the data are “icky” after a certain point. Sometimes your sample has elements with nearby edges, thus limiting the range over which you can actually measure the data. An example is shown in the next plot, the Ti K edge is at 4966 eV and the Ba LIII edge is at 5247 eV. A careless choice of spline and normalization range will lead to a data processing disaster.
The Ti K and Ba LIII edges of BaTiO3 .
Of course, truncation is not the only way of dealing with this issue. A careful choice of the spline, pre-edge, and normalization ranges is usually sufficient to treat any strange features at the beginning or end of the data set. So which is better? I think it's a matter of preference. As long as you understand what you are doing and process all your data in a consistent, defensible manner, you can use either approach.
This truncating algorithm is the same as the one used by the truncating feature of the column selection dialog.
