Ultra-Sensitive Multi-Gas Detection (CS₂/SO₂/H₂S/OCS) Using Spectral Reconstruction Combined with Differential...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Sulfur hexafluoride (SF₆) is a potent greenhouse gas used in electrical equipment.
• Decomposition of SF₆ produces various toxic byproducts, including CS₂, SO₂, H₂S, and OCS.
• Accurate monitoring of these decomposition products is crucial for equipment maintenance and environmental protection.

Purpose of the Study:

• To develop a sensitive and accurate detection system for simultaneous quantification of SF₆ decomposition products.
• To overcome the limitations of conventional methods in detecting weak or overlapping spectral signals.
• To enable high-sensitivity monitoring of SF₆ decomposition in power equipment.

Main Methods:

• Combines ultraviolet differential optical absorption spectroscopy (UV-DOAS) with thermal conversion.
• Employs spectral reconstruction at room temperature to resolve overlapping CS₂ and SO₂ spectra.
• Utilizes differential temperature conversion to transform CS₂, H₂S, and OCS into SO₂ for sensitive detection.

Main Results:

• Achieved simultaneous quantification of CS₂, SO₂, H₂S, and OCS at ppb/ppm levels.
• Demonstrated effective spectral reconstruction for resolving overlapping CS₂ and SO₂ absorption bands.
• Validated the system's performance in SF₆ backgrounds with a relative deviation below 5.78% across different temperatures (room temperature, 800 K, 1100 K).

Conclusions:

• The developed system offers a novel strategy for high-sensitivity monitoring of SF₆ decomposition products.
• This approach overcomes limitations of traditional spectroscopic techniques for analyzing weak or overlapping absorption bands.
• The system has significant potential for application in power equipment diagnostics and environmental sulfide monitoring.