ANGSTROM
Unit of measure for x-ray wavelengths. Wavescan intensities and KLM markers may be displayed in spectrometer or angstrom units.
The conversion of spectrometer to angstrom units is by default based on the calculated spectrometer offset from the theoretical peak position compared to the actual or measured peak position using the following expression:
where: 
= the theoretical spectrometer peak
position
= the actual or measured spectrometer
peak position
This assumes that any inaccuracy in spectrometer position from the exact theoretical position is a constant offset regardless of the spectrometer position. Usually this is sufficient for most purposes, where the spectrometers are not too far out of alignment. Of course, you will determine the exact peak positions in practice; the accuracy discussed here affects the initial locating of spectrometers and labeling of peaks in the Plot! displays.
For ultimate accuracy in initial spectrometer locating and peak labels in Plot!, use of the multiple peak calibration option in the StartWin application will produce a calibration table that will be used by Probe for EPMA in calculating a variable spectrometer offset based on the spectrometer position for each spectrometer and crystal combination and for each Ka, Kb, La, Lb, Ma or Mb family. See the PROBEWIN.INI keyword "UseMultiplePeakCalibrationOffset" for more information on the use of this variable spectrometer offset feature.