Analysis of Optical Fiber Methane Gas Detection System

With the advances in clean energy, natural gas (methane) takes a greater proportion in total energy consumption. Methane gas detection technology has become an important research direction for fire alarm area. Using near-infrared absorption spectroscopy method, this gas detection technology has many unique advantages, such as intrinsic safe, good stability, good selectivity, long working life, etc. In this paper, a gas detection system based on wavelength modulation and second harmonic (2f) signal detection technology is proposed; the process of the first and second harmonic demodulation is simulated; the feasibility of using first harmonic as light intensity reference and the linear relationship between the concentration and second harmonic is analyzed. Finally, a theoretical guidance for product developing with above technology is provided as well.