Continuous monochrometer drift compensation of a spectral monochromator

Claim 1

A method of continuously compensating for drift of peak positions of spectral lines in a spectral monochromator including radiation means for generating elemental radiation for atomic elements, optical dispersion means receptive of the radiation for producing a series of spectral bands each having a peak spectral position associated with maximum radiation intensity, detector means selectively receptive of a spectral function of a spectral band for producing an intensity signal representative of the intensity of the spectral fraction being received, scanning means responsive of a scanning signal for varying relative orientation of the dispersion means and the detector means such that the series of spectral bands is scanned across the detector means in spectral positions corresponding to successive spectral fractions, and computer means receptive of the intensity signal for generating the scanning signal and calculating spectral position of each peak; the method comprising the steps of, in sequence: Establishing a series of spectral windows each encompassing a selected spectral band and having an initial window center, successively scanning through each of the windows so as to determine a maximum peak spectral position for a corresponding band, calculating a spectral position error of the peak position from the initial center for each corresponding window, calculating a drift offset equal to a functional average of the position errors, calculating a revised spectral center for each window equal to the initial center plus the corresponding drift offset, shifting each window to its revised center, and repeating the step of successively scanning through each of the windows so as to determine a new peak position for each corresponding band, whereby each new peak position is maintained near a spectral center of each corresponding window.

Claim 2

A method of continuously compensating for drift of peak positions of spectral lines in a spectral monochromator including radiation means for generating elemental radiation for atomic elements, optical dispersion means receptive of the radiation for producing a series of spectral bands each having a peak spectral position associated with maximum radiation intensity, detector means selectively receptive of a spectral function of a spectral band for producing an intensity signal representative of the intensity of the spectral fraction being received, scanning means responsive of a scanning signal for varying relative orientation of the dispersion means and the detector means such that the series of spectral bands is scanned across the detector means in spectral positions corresponding to successive spectral fractions, and computer means receptive of the intensity signal for generating the scanning signal and calculating spectral position of each peak; the method comprising the steps of, in sequence: Establishing a series of spectral windows each encompassing a selected spectral band and having an initial window center, successively scanning through each of the windows so as to determine a maximum peak spectral position for a corresponding band, calculating a spectral position error of the peak position from the initial center for each corresponding window, calculating a drift offset equal to a functional average of the position errors, calculating a revised spectral center for each window equal to the initial center plus the corresponding drift offset, shifting each window to its revised center, and repeating the step of successively scanning through each of the windows so as to determine a new peak position for each corresponding band, whereby each new peak position is maintained near a spectral center of each corresponding window.