Metrological problems of gas analyzers based on wavelength-scanned cavity ring-down spectroscopy

Wavelength-scanned cavity ring-down spectroscopy (WS CRDS) is used in gas analysis. Calibration gas mixtures containing carbon monoxide, carbon-12 dioxide, carbon-13 dioxide, methane, and formaldehyde are used to determine the metrological characteristics of WS CRDS gas analyzers. Most experimental results are in agreement with the declared data. For gas mixtures in which the gas matrix differs from air, the broadening of spectral lines related to the interaction of particles causes significant errors in the concentration measurements. Such effects that neutralize the advantages of the WS CRDS method are studied in this work. The coefficients that can be used to correct the results of the WS CRDS gas analyzers and compensate for errors related to different gas matrices are presented.