New vacuum wavelengths for nine lines of He I in the near ultraviolet and visible regions are given. They were obtained by measurement relative to 5462.2707 A and 4359.5625 A of Hg198 I with an evacuated Fabry-Perot interferometer. Liquid-nitrogen cooled helium lamps were used. Interference fringes were obtained for the helium line 5017 A with spacers up to 50 mm in length. The wavelength of this line, which was used as a reference wavelength in some previous work on the Rydberg constant, is found to be 5017.0772±0.0003 A (vac.) relative to the stated values for the two standards.
WILLIAM C. MARTIN, "New Wavelengths for Some Helium (He I) Lines," J. Opt. Soc. Am. 50, 174-176 (1960)