Incoherent broad-band cavity-enhanced absorption spectroscopy for simultaneous trace measurements of NO2 and NO3 with a LED source

摘要: In the past decade, due to a growing awareness of importance air quality and pollution control, many diagnostic tools techniques have been developed detect quantify concentration pollutants such as NOx, SOx, CO, CO2. We present here an Incoherent Broad-Band Cavity-Enhanced Spectroscopy (IBB-CEAS) set-up which uses LED emitting around 625 nm for simultaneous detection NO2 NO3. The light transmitted through high-finesse optical cavity filled with gas sample is detected by low resolution spectrometer. After calibration spectrometer reference sample, linear multicomponent fit analysis absorption spectra allows measurements NO3 concentrations in flow ambient air. optimal averaging time found be on order 400 s appears limited drift At this smallest detectable 2×10−10 cm−1, corresponds limits 600 pptv 2 This compact cost instrument promising tool control urban environments.