High-sensitivity detection of hazardous SO₂ using 266 nm UV laser

Abstract

Pulsed laser resonant photoacoustic spectroscopy was applied for detection of highly toxic SO₂ with 266 nm as the excitation source. An extra-cavity longitudinal resonant cell, was designed and fabricated to enhance the sensitivity of the system, which is capable of detecting the trace amount of SO₂. As a process of signal-to-noise ratio optimization, the parametric dependence of the PA signal was carried out and the sensitivity achieved with our system was as low as 4 ppb, which is considered to be a sufficient level for the detection of ambient SO₂ in the atmosphere. This study could be an antecedent for the design of a portable SO₂ sensor.

Keywords:

• SO₂ detection
• photoacoustic spectroscopy
• environmental hazards
• acid rains
• monitoring of atmospheric gases
• pollutants
• trace gases
• global warming

Acknowledgments

The support by the Physics Departments and King Fahd University of Petroleum and Minerals under project # SABIC 2005/11 is gratefully acknowledged.