The wavelengths of 19 spectral lines in the region 253-579 nm emitted
by Hg pencil-type lamps were measured by Fourier-transform spectroscop
y. Precise calibration of the spectra was obtained with wavelengths of
Hg-198 as external standards. Our recommended values should be useful
as wavelength-calibration standards for moderate-resolution spectrome
ters at an uncertainty level of 0.0001 nm.