• Existing methods cannot simultaneously measure concentrations of multiple gases with high precision across a wide range, hindering applications in industries and environmental monitoring.
• A method and apparatus are required to accurately measure multiple gases across various concentrations, addressing challenges in biogas monitoring, industrial processes, medicine, and environmental tracking.

The present invention relates generally to gas sensing and in particular to measurement of gases in gas mixtures.

Excitation Source:

• Utilizes a pulsed or continuous wave broadband infrared (IR) light source to generate excitation in the gaseous sample.

Modulation:

• Modulates the output of the light source using an optical chopper to create a precise modulation frequency.

Selective Detection:

• The method which has gaseous sample comprises a gas selected from CH4, CO, water vapor, H2S,C2H2, NH3, H2CO, C2H4, C2H6, C3H8, C4H8, N2O, NO or CO2, or mixtures thereof. Passes the modulated spectral output through a specific bandpass filter tailored to the target gas species being detected.

Photoacoustic Effect:

• Illuminates the gaseous sample in a resonant photoacoustic cell with the modulated and filtered light, causing the target gases to absorb energy and emit acoustic signals.

Acoustic Measurement and Computation:

• Utilizes a microphone to measure acoustic signals, enabling concentration computation of target gases via photoacoustic spectroscopy in the infrared range, ensuring precise detection from trace levels to 100% concentration.