FTIR spectrometer with 30 m optical cell and its applications to the sensitive measurements of selective and nonselective absorption spectra

•A description of FTIR spectrometer coupled with 30 m base length cell is presented.•Achieved threshold sensitivity is in the level of 8.6x10−10 cm−1.•New weak H2O absorption lines were measured within 2400 and 2560 cm−1 region and assigned.

A description of the spectroscopic complex at V.E. Zuev Institute of Atmospheric Optics, SB RAS, operating in a wide spectral range with high threshold sensitivity to the absorption coefficient is presented. Measurements of weak lines and nonselective spectra of CO2 and H2O were performed based on the built setup. As new application of this setup, positions and intensities of 152 weak lines of H2O were measured between 2400 and 2560 cm−1 with threshold sensitivity of 8.6×10−10 cm−1, and compared with available calculated and experimental data. Essential deviations between the new intensity measurements and calculated data accepted in HITRAN 2012 and GEISA 2015 forthcoming release are found.