In-motion monitoring of atmospheric methane and ethane using a mid-infrared dual-gas simultaneous detection sensor

For realize the atmospheric alkane gases detection in wide area and long distance, a dual-gas simultaneous methane and ethane detection sensor was demonstrated and conducted in Greater Houston area (GHA). A continuous-wave (CW) interband cascade laser (ICL) was used as the light source, a high-speed data acquisition card (DAQ) was used to sampling the detection signal, a LabVIEW based laptop platform incorporated signal generation, signal acquisition, harmonic extraction, concentration calculation and display. Response time considering sampling period, local wind and vehicle speeds are calculated, noise levels for mobile and laboratory operation on the CH₄ and C₂H₆ sensor system are all evaluated. Concentration measurement of methane and ethane in one road was shown, as well as a 2-D concentration mapping result in one block, the varied relationship between these two kinds of gases was analyzed. This work provide the technology for detecting the leakage of alkane gases and monitoring the atmospheric gases.