MONOCHROMATOR DRIFT COMPENSATION

摘要

ID-3809 Iterative compensation of drift of peak positions of spectral lines in a spectral monochromator including a grating, a detector of spectral fractions of a spectral band, a stepper motor for varying relative orientation of the grating and the detector, and a computer. A series of computer-defined spectral windows each encompasses one spectral band and has a nominal spectral position and an initial spectral center. Each window is scanned such as to determine a peak spectral position. Calculations are made for a spectral offset of the peak position from the initial center for each corresponding window, an average of the offsets for the peaks as a linear function of window position, and a revised spectral center for each window equal to the initial center plus the average offset for the window position determined from the linear function. Each window is shifted correspondingly. The step of successively scanning through each window is repeated such as to determine a new peak position for each corresponding band, whereby each new peak position is maintained near the spectral center of each corresponding window.