개회로 CO₂/H₂O 적외선 기체 분석기 보정 인자의 변동성과 장기 플럭스 관측에 미치는 영향 = Variability of Calibration Factors for Open-Path CO₂/H₂O Infrared Gas Analyzer and Its Effect on Long-Term Flux Measurement

다국어 초록 (Multilingual Abstract)

Calibration experiments were executed to document pertinent calibration methods for open-path infrared gas analyzer (OP-2) in field operations and to quantify their performance characteristics in continuous long-term flux measurements. Based on our results, we concluded: (1) flow rate of 2.0 L min$^{-1}$ can be used for calibration instead of the recommended 0.5 L min$^{-1}$ . Such faster flow rate brings the sampled air in the calibration hood at equilibrium within 5 min for $CO_2$ and 10 min for $H_2O$; (2) after reaching equilibrium, two-minute average sampling for related variables per each concentration may be sufficient; (3) use of four concentration is needed to derive the nonlinear calibration equation for water vapor with 1% uncertainty of flux measurement; and (4) the resultant calibration interval for OP-2 for both $CO_2$ and $H_2O$ is approximately one month.