Real-Time Monitoring of SO(2) Emissions Using a UV Camera with Built-in NO(2) and Aerosol Corrections

Nitrogen dioxide (NO(2)) absorption correction of the sulfur dioxide (SO(2)) camera was demonstrated for the first time. The key to improving the measurement accuracy is to combine a differential optical absorption spectroscopy (DOAS) instrument with the SO(2) camera for the real-time NO(2) absorption correction and aerosol scattering correction. This method performs NO(2) absorption correction by the correlation between the NO(2) column density measurement of the DOAS and the NO(2) optical depth of the corresponding channel from the SO(2) camera at a narrow wavelength window around 310 and 310 nm. The error of correction method is estimated through comparison with only using the second channel of the traditional SO(2) camera to correct for aerosol scattering and it can be reduced by 11.3% after NO(2) absorption corrections. We validate the correction method through experiments and demonstrate it to be of greatly improved accuracy. The result shows that the ultraviolet (UV) SO(2) camera system with NO(2) absorption corrections appears to have great application prospects as a technology for visualized real-time monitoring of SO(2) emissions.