Methane measurement method based on F-P angle-dependent correlation spectroscopy

Area of Science:

• Spectroscopy
• Gas Sensing
• Optical Physics

Background:

• Accurate and selective gas detection is crucial for environmental monitoring and industrial safety.
• Traditional methods often face challenges with sensitivity, selectivity, and interference.

Purpose of the Study:

• To develop and validate a novel gas measurement method using Fabry-Perot (F-P) angle-dependent correlated spectroscopy.
• To achieve highly sensitive and selective detection of methane (CH4) gas.

Main Methods:

• Designed an F-P etalon tuned to the CH4 absorption peak.
• Established an angle-scanning measurement system for correlated spectroscopic detection.
• Developed a conical incidence model to analyze beam divergence effects.

Main Results:

• Achieved distinct absorption signals by aligning F-P interference peaks with CH4 absorption.
• Demonstrated a linear relationship between apparent absorbance and CH4 concentration.
• Reached a 3σ detection limit of 720 ppm for CH4 and showed robust resistance to cross-interference.

Conclusions:

• The F-P angle-dependent correlated spectroscopy method offers a non-dispersive approach for sensitive and selective gas sensing.
• This technique shows significant potential for developing advanced gas sensors and imaging applications.