Vehicle‐mounted mobile mid‐infrared high‐precision atmospheric ethane sensor system

Abstract

Ethane (C 2 H 6 ) is an important gas in environmental monitoring, especially in urban areas, and the development of vehicle-mounted mobile C 2 H 6 sensors is meaningful for high-efficiency and wide-range detection of C 2 H 6 concentration levels. Based on tunable diode laser absorption spectroscopy, a sensor system for the detection of trace C 2 H 6 concentration in the atmosphere was developed using wavelength modulation spectroscopy. An interband cascade laser with a central wavelength of 3337 nm and a multipass gas cell (MPGC) with an optical path length of 26.4 m was used as core optical components. The pressure in the MPGC was optimized at 200 Torr, and such pressure was stabilized by a selfdeveloped pressure control system. The sensor system was compactly integrated into a standalone instrument with a dimension size of 52 × 33 × 28.8 cm 3 . The detection limit (1σ) was measured to be 3.45 parts per billion at an averaging time of 0.5 s. Forty-eight-hour field experiment and vehicle-mounted mobile measurement of atmospheric C 2 H 6 levels with concentration mapping were carried out on the Jilin University campus to validate the practical application ability of the system.