Acetylene Density Measurement System Based on Differential and Harmonic Detection

An easy-realizable gas sensing system using absorption type optical fiber is studied and discussed, in order to improve the detection sensitivity and anti-interference ability of popular acetylene gas sensor. Using ASE as light source, the detection sensitivity has been greatly improved. Wavelength modulation on ASE broadband light source using fiber Bragg grating and PZT to obtain narrowband reflected output light. At the same time, using a combined structure of differential detection and harmonic detection, eliminates the influence of light source power fluctuation, the absorption coefficient change with the environment and other factors on the measurement results, and effectively improves the sensitivity and the anti-interference ability of the system.