Absorption cross sections of CHF3 (HFC-23) in synthetic air at 296 K

Abstract

We report high accuracy absorption cross sections of fluoroform (CHF₃) in synthetic air at 296 K. The measured FTIR spectra underwent extensive processing, yielding accurate integrated intensity values for seven ro-vibrational bands in the mid-infrared region. Integrated cross sections in the regions of the major fundamental bands ${\nu }_3$, ${\nu }_4$ and ${\nu }_2/{\nu }_5$ dyad have expanded uncertainties below 1.3 % (k = 2). Integrated cross sections in the region of combination bands ${\nu }_2+{\nu }_6$ and ${\nu }_2+{\nu }_3$ were determined with uncertainties less than 2 % (k = 2). Comparison of the integrals with values from the PNNL database showed consistency between both datasets. The influence of self-broadening effects of the spectral profiles, and the impact on the averaging procedures employed in the PNNL database and the current work are addressed. Experimental spectra and the corresponding composite spectra are available online in two archives: doi:10.7795/720.20250709 (experimental cross sections) and doi:10.7795/720.20250708 (composite spectra).