Frequency shifts of a methane standard

Frequency shifts are calculated for a methane standard the reproducing the frequency of the molecular transition generating λ = 3.39 μm radiation by the methods of absorption saturation and dispersion. Allowance is made for the simultaneous influence of the quadratic Doppler effect, of splitting because of the recoil effect, of collisional and transit broadening, and of a magnetic hyperfine structure of the spectral line.