A limitation of photodiode array detectors for spectroscopic intensity measurements relates to the spacing of the diodes and the errors generated when a spectral line is not in exact registry with the diode or diodes from which its intensity is being measured. These misregistry intensity errors, which may be as high as 25 to 30%, are documented for a range of spectral bandwidths and for single diode (pixel) intensities and multiple diode summations of intensities.
R. K. Winge, V. A. Fassel, and D. E. Eckels, "Spectral Line-Diode Registry Effects with Photodiode Array Detectors," Appl. Spectrosc. 40, 461-464 (1986)