Traceable $\hbox{CO}_{2}\hbox{-}{\rm R}(12)$ Line Intensity for Laser-Spectroscopy-Based Gas Analysis Near 2 $\mu \hbox{m}$

The authors determined the CO 2 -R(12) line intensity (region) employing direct absorption spectroscopy improved by several high-accuracy-oriented new developments, with a relative uncertainty of 0.5%, k = 1. All the input quantities are traceable and the uncertainty was evaluated Guide to the Expression of Uncertainty in Measurement compliant. The result for the line intensity is in agreement with the high-resolution transmission molecular absorption database value but 1.4% smaller. It was applied to partial pressure measurements of CO 2 in N 2 for samples of gravimetric-traceable known amount of CO 2 fractions. The differences of the results obtained from direct absorption spectroscopy and the gravimetric values were 0.4% or less