Knowledge Bank

Absolute intensities in the $\nu 4$- fundamental of $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CH4$ have been deduced from spectral transmittance measurements at 153 and 296 K,using a $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C$ enriched (99.6%) sample of $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CH4$ and a Fourier transform spectrometer with spectral resolution of $0.06cm-1$. The line strengths are 96-98 percent of the corresponding values for $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CH4$. The absolute intensity of the band is $123cm-2atm-1$ at 296 K.