Atmospheric CO2 monitoring with single-cell NDIR-based analyzers

作者：Stephens B B^*; Miles N L; Richardson S J; Watt A S; Davis K J

来源：Atmospheric Measurement Techniques, 2011, 4(12): 2737-2748.

DOI：10.5194/amt-4-2737-2011

We describe CO2 concentration measurement systems based on relatively inexpensive single-cell non-dispersive infrared CO2 sensors. The systems utilize signal averaging to obtain precision (1-sigma in 100 s) of 0.1 parts per million dry air mole fraction (ppm), frequent calibrations and sample drying in order to achieve state-of-the-art compatibility, and can run autonomously for months at a time. Laboratory tests indicate compatibility among four to six systems to be +/- 0.1 ppm (1-sigma), and field measurements of known reference-gases yield median errors of 0.01 to 0.17 ppm with 1-sigma variance of +/- 0.1 to 0.2 ppm. From May to August 2007, a system co-located with a NOAA-ESRL dual-cell NDIR system at the WLEF tall tower in Wisconsin measured daytime-only daily averages of CO2 that differ by 0.26 +/- 0.15 ppm (median +/- 1 sigma), and from August 2005 to April 2011 a system co-located with weekly NOAA-ESRL network flask collection at Niwot Ridge, Colorado measured coincident CO2 concentrations that differed by -0.06 +/- 0.30 ppm (n = 585). Data from these systems are now supporting a wide range of analyses and this approach may be applicable in future studies where accuracy and initial cost of the sensors are priorities.

• 出版日期2011