2F/1F wavelength modulation spectroscopy method for airborne tdlas oxygen sensor with emd-savitzky-golay filtering

Researchers in Southwest Research Institute and OXIGRAF Company have designed the airborne oxygen sensor for aircraft inerting system. At present, the research on related fields in China is still in the blank state. The real-time and accurate detection of oxygen concentration is the key problem to protect the explosion of aircraft fuel tank. Therefore, we designed 2f/1f wavelength modulation spectroscopy method for Airborne Tunable Diode Laser Absorption Spectroscopy (TDLAS) Oxygen Sensor with EMD-Savitzky-Golay Filtering. First, raw signals are demodulated into first harmonic(1f) and second harmonic(2f) signals. In order to eliminate interference, smooth the signal, 1f and 2f were filtered by EMD-Savitzky-Golay algorithms respectively. The signals were reconstructed effectively by using the the accuracyand stability of the system are both improved. Finally, the 1f normalization 2f method(WMS-2f/1f) was developed to reduce the influence of light intensity signal attenuation. The prototype is designed and the platform is built. The results show that EMD-savitzky-Golay filter can improve the signal-to-noise ratio, expand the measurement range and detection limit.