Calibration points tab
This tab contains the numerical data necessary to overview the calibration.
These comprise the current status (modified or unmodified), and the calibration point list as well. The point list contains two or more editable calibration points, to which a linear fit is performed, thus determining a channel – channel FWHM calibration line. If only two points are used, the line will necessarily go through the points. If more than two points are specified, a least–square fit is performed, in order to determine the optimum calibration line between scattering points.
To delete a specific FWHM calibration point, select it by clicking on it with the mouse, or make it active by pressing the up or down cursor arrow keys, and click Delete button.
Entering new points manually
If you do not want to use HyperLab's visual calibration point adding facility, just want to enter predefined calibration points, press the (cursor down) key repeatedly, while you leave the last point's row, and a new, empty row automatically created. Type in the proper values, then press (cursor up) key to leave the edited calibration point row. If you want to enter a completely new calibration, first remove all calibration points, then the add them one by one.
Modifying channel positions
To modify the channel position of a specific calibration point, you have two options: manual editing or borrowing.
To edit the value by hand, just click on the channel number value, and type the new number. To borrow, you should use the borrow button of the FWHM field.
Modifying FWHM values
FWHM values may also be modified by either manual editing, or by getting the exact fitted FWHM values from the active HyperLab spectrum. Manual editing may be initiated by simply clicking on an FWHM value and typing its new value in channels.
If you want to borrow a fitted peak width value from the current spectrum, click on the FWHM value, then on the ellipsis [...] button beside the number. The spectrum fitting window appears now. Click with the position getting tool on a peak.
The FWHM calibration editor will appear again, and the clicked peak's exact fitted peak width will be used as the FWHM value of the calibration point. Should you want to cancel the borrowing process, press Esc key.
Note: after borrowing, the channel position of the FWHM point is also updated to the position of the fitted peak. This behavior is different from what you can experience in the energy calibration editor.
Adding new points by visual selection
HyperLab also makes it possible to add a new calibration point via a convenient method. If you click New button under the list of calibration points, HyperLab displays the spectrum evaluation window, where you can click a fitted peak for FWHM. After clicking, the fitted peak position and peak width values are used as a new calibration point. This way addition of a new calibration point may be accomplished rather quickly.