The relative intensities of 478 nickel arc lines have been measured photoelectrically between 3359 and 5893A with an accuracy of better than one percent for the good lines. The dc arc was operated under steady conditions at a current of 2 amperes. Corrections for self-absorption have been determined. The influence of arc fluctuations has been minimized by recording always the ratio of the output of a scanning tube to that of a fixed tube placed on a control line.
ROLAND L. HEID and G. H. DIEKE, "Intensity Measurements in the Arc Spectrum of Nickel," J. Opt. Soc. Am. 44, 402-409 (1954)