Research on high performance combustible gas concentration sensor based on pyramid beam splitter matrix

Area of Science:

• Sensor Technology
• Optical Engineering
• Gas Detection

Background:

• Combustible gas detection requires improved accuracy, sensitivity, and reliability, especially in harsh environments.
• Existing optical path structures present limitations in sensitive element design.
• Novel optical path designs offer potential for enhanced gas detection capabilities.

Purpose of the Study:

• To develop a new optical path structure for sensitive elements to improve combustible gas concentration detection.
• To enhance the accuracy, sensitivity, and reliability of combustible gas sensors.
• To validate the performance of the newly designed sensor under various conditions.

Main Methods:

• A novel optical path structure for the sensitive element was designed using a Pyramidal beam splitter matrix.
• Infrared light source modulation employed multi-frequency point signal superimposed modulation technology.
• A 4-channel combustible gas concentration detection algorithm based on spectral refinement was utilized for concentration and confidence level calculations.

Main Results:

• The sensor demonstrated full-range measurement of methane (CH4).
• Reliability reached 0.01 parts-per-million (PPM) at the lower explosive limit (LEL) of CH4 (5%).
• Sensor sensitivity was as high as 0.5 PPM, maintaining PPM-level detection even with a 2/3 obstructed optical window, 85% humidity, or 100 mg/m³ dust concentration.

Conclusions:

• The newly designed sensor significantly improves sensitivity, robustness, reliability, and accuracy in combustible gas detection.
• The Pyramidal beam splitter matrix-based optical path structure and spectral refinement algorithm are effective for high-performance gas sensing.
• The sensor exhibits exceptional resilience and accuracy under challenging environmental conditions, suitable for harsh industrial applications.