Fig. 1. Simulated absorption spectra. (a) Absorption spectrum of H₂O around 7181 cm^-1; (b) absorption spectra of CO₂ around 4990 cm^-1

Fig. 2. Structural schematics of analyzers. (a) Structural schematic of H₂O analyzer; (b) structural schematic of CO₂ analyzer

Fig. 3. Schematic and photo of measurement system. (a) Schematic of measurement system; (b) photo of measurement system

Fig. 4. Spectral signals of different concentrations of CO₂. (a) Direct absorption signal; (b) second derivative spectral signal

Fig. 5. Linear correlation between concentrations and peak values

Fig. 6. Instrument installation photos

Fig. 7. Comparisons for continuous 4 h data and 1 s data. (a) H₂O concentration data; (b) CO₂ concentration data

Fig. 8. Allan variance analysis of TDLAS-CO₂/H₂O analyzers. (a) TDLAS-CO₂ analyzer; (b) TDLAS-H₂O analyzer

Fig. 9. Monitoring data for a continuous week of TDLAS-H₂O/CO₂ analyzer. (a) TDLAS-CO₂ analyzer; (b) TDLAS-H₂O analyzer