Simultaneous measurements of SO2 and SO3 in the heterogeneous conversions of SO2 using QCL absorption spectroscopy

Temperature measurement of SO2 based on mid‐infrared laser absorption spectroscopy

“…Here, the two absorption lines of the SO 2 are selected to 1396.844 and 1396.921 cm −1 based on the selection rules. 12,13 The red laser (Changchun New Industries, Model MRL-III-635L) combined with rotating mirror is used for optical beam adjustment and optimization. Laser passes through a temperature-adjustable MPC (Homemade) and is received by a cooled MCT (HgCdTe) mid-infrared detector.…”

“…The laser is modulated with a sawtooth wave superimposed by a sine wave, and the absorption signal is demodulated by Lock in Amplifier (Standford Research System, Model SR830) at 1f and 2f harmonics. Here, the two absorption lines of the SO 2 are selected to 1396.844 and 1396.921 cm −1 based on the selection rules 12,13 . The red laser (Changchun New Industries, Model MRL‐III‐635L) combined with rotating mirror is used for optical beam adjustment and optimization.…”

Quartz-Enhanced Photoacoustic Sensor Based on a Multi-Laser Source for In-Sequence Detection of NO2, SO2, and NH3

“…Several optical-based sensors have been developed to detect air pollutants, with the final aim of on-field, real-time detection. Trace concentrations of NH 3 , NO 2 , and SO 2 were measured by employing detection techniques based on direct detection of absorbed light, such as tunable diode laser absorption spectroscopy [14][15][16] and cavity ringdown spectroscopy [17][18][19]. Among the optical techniques for gas sensing, Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) exploits the photoacoustic effect occurring in a gas sample when a modulated, resonant light is absorbed by the target analytes.…”

Ni-doped Al2O3 sensor for effective SO3 gas adsorption and sensing

“…[19][20][21] Only a few studies have discussed SO 3 gas sensing up to this point, but sensing at room temperature and low concentrations was not addressed. [22][23][24] The objective of this study is to study the solid-state device sensing of SO 3 gas. The study primarily focuses on low-high concentration detection and reducing the sensing temperature.…”