H_2~(16)O absorption spectrum between 22250 and 22800 cm~(-1): Fourier transform spectroscopy with bright light source

摘要

Measurements of water vapor absorption spectra in the visible spectral region near 0.44 mkm are performed using FT-spectrometer IFS-125M and Light-emitting diode (LED) as source of radiation. Water vapor spectrum has been obtained by averaging over 17136 scans recorded at 34,8 m optical path length, temperature 24 ± 1 C and pressure of sample 24,8 mBar. Due to strong emission of LED source it was possible to achieve signal-to-noise ratio about 10~4 and to record weak lines with intensities of 6 10~(-27) cm/molecule. Comparisons with results of early works are made.