Automatisierung Von Pulverdiffraktometern und Auswertung der Diffraktogramme Auf Einem PC

Literatur

By commercial stepper motors, stepper controllers and 8052AH-Basic boards older X-ray diffractometers can easily be updated to automated step scan machines. Mostly the old AC synchronous motor may be left in place (e.g. for PHILIPS or SIEMENS diffractometers). The complete step scan file (*.RAW file) is transfered to a PC after finishing the measurement of one powder pattern. The evaluation program, written in Turbo-Pascal, perforins the following tasks: recognition of run-aways (and the possibility to remove them), background subtraction, data smoothing after Savitzky & Golay (1964), α₂-stripping, and peak detection using 2nd and 1st derivatives. A zoom routine to manually cancel false peaks and to set undetected ones will be added soon, a profile fitting routine is planned. The final list of found d-values and intensities (*.DIF file) can be used for a lattice constant refinement including site or zero point correction by the program LATCO.