Real-time measurement of the NO2concentration in ambient air using a multi-mode diode laser and cavity enhanced multiple line integrated absorption spectroscopy
التفاصيل البيبلوغرافية
العنوان:
Real-time measurement of the NO2concentration in ambient air using a multi-mode diode laser and cavity enhanced multiple line integrated absorption spectroscopy
We report on the measurement of the NO 2 concentration in ambient air using a highly sensitive trace gas detector based on a simplified design that uses a multi-mode diode laser and cavity enhanced multiple line integrated absorption spectroscopy. The broad frequency range of the laser covers a large number of absorption lines of NO 2 and excites a large number of cavity modes. The off-axis cavity arrangement reduces the detector’s susceptibility to vibration. The detector was calibrated using known concentrations of NO 2 in zero air and used to measure the concentration of NO 2 in ambient air in our laboratory. A sensitivity of 75 ppt was achieved.