Novel Broadband Cavity-Enhanced Absorption Spectrometer for Simultaneous Measurements of NO2 and Particulate Matter

A novel instrument based on broadband cavity-enhanced absorption spectroscopy has been developed using a supercontinuum broadband light source, which showcases its ability in simultaneous measurements of the concentration of NO2 and the extinction of particulate matter. Side-by-side intercomparison was carried out with the reference NOx analyzer for NO2 and OPC-N2 particle counter for particulate matter, which shows a good linear correlation with r2 > 0.90. The measurement limits (1 sigma) of the developed instrument were experimentally determined to be 230 pptv in 40 s for NO2 and 1.24 Mm-1 for the extinction of particulate matter in 15 s. This work provides a promising method in simultaneously monitoring atmospheric gaseous compounds and particulate matter, which would further advance our understanding on gas-particle heterogeneous interactions in the context of climate change and air quality.

Automated summary

A novel instrument based on broadband cavity-enhanced absorption spectroscopy has been developed for simultaneous measurements of NO2 concentration and particulate matter extinction. It shows good linear correlation (r2 > 0.90) with reference analyzers. The instrument has measurement limits of 230 pptv for NO2 in 40s and 1.24 Mm-1 for particulate matter extinction in 15s. This work provides a promising method for monitoring atmospheric gaseous compounds and particulate matter simultaneously.