Measurement of Atmospheric CO2 Column Concentrations Based on Open-Path TDLAS

Abstract

Monitoring of CO2 column concentrations is valuable for atmospheric research. A mobile open-path system was developed based on tunable diode laser absorption spectroscopy (TDLAS) to measure atmospheric CO2 column concentrations. A laser beam was emitted downward from a distributed feedback diode laser at 2 μm and then reflected by the retroreflector array on the ground. We measured the CO2 column concentrations over the 20 and 110 m long vertical path. Several single-point sensors were distributed at different heights to provide comparative measurements for the open-path TDLAS system. The results showed that the minimum detection limit of system was 0.52 ppm. Some similarities were observed in trends from the open-path TDLAS system and these sensors, but the average of these sensors was more consistent with the open-path TDLAS system values than the single-point measurement. These field measurements demonstrate the feasibility of open-path TDLAS for measuring the CO2 column concentration and monitoring carbon emission over large areas.

Integrated near-infrared QEPAS sensor based on a 28 kHz quartz tuning fork for online monitoring of CO2 in the greenhouse

“…Tunable diode laser absorption spectroscopy (TDLAS) and photoacoustic spectroscopy (PAS) have been used for CO 2 gas detection. These sensors usually reach the detection limit of ppm CO 2 concentration level [16] , [17] . Photoacoustic spectroscopy (PAS) technology converts the absorption of light energy into sound energy and performs measurement [18] .…”

Application and algorithm research of TDLAS

“…Ping Gong et al established a onefold humidness indicator for H2O gas and heavy-oxygen water vapor measurement based on TDLAS [18]. Fengxin Xin et al developed a mobile open optical path atmospheric CO2 column concentration measurement system based on TDLAS [19]. Zhong Li et al proposed a numerical simulation method independent of spectral line shape characteristics.…”

Research on the Seed Respiration CO2 Detection System Based on TDLAS Technology

“…TDLAS has the characteristics of high sensitivity and high resolution and has been widely used in trace gas detection [10][11][12][13][14]. Many scholars at home and abroad have conducted research on TDLAS technology in the CO 2 concentration detection method and detection sensitivity [15][16][17][18][19]. TDLAS detection methods mainly include WMS and direct absorption spectroscopy.…”