Compact remote optical system for real time measurement of aerosol emissions

Demonstrating particle matter (PM) emissions compliance with environmental regulations is required for operation of any industrial, commercial or military facility. Emission sources are initially screened based on their visible opacity via US EPA Method 9 standard. Nowadays, it is rather surprising that opacity is still visually determined by human eyes with smoke school training and semi-annual certification. Nonetheless, opacity alone doesn't reveal particle concentration and size distribution which is crucial to determine PM values. It would be desirable to have an automated, calibratable device to make such a measurement with higher accuracy and reliability and is not available to date. We present our preliminary work on developing a compact, hand portable system capable of quantitatively determining plume optical opacity in combination with possible particle concentration and size distribution (and hence PM) measurement for standoff distances up to 150 meters. Our benchtop lidar-based system was built with a frequency-doubled Q-switched Nd:YAG laser and an optical receiver. We have demonstrated the feasibility of a remote-capable optical sensor system for real-time continuous monitoring of visible emission plumes and its effectiveness for quantitative opacity measurement. The hand-portable Remote Plume Particulate Matter (RPPM) meter being developed will be capable of determining opacity and PM load from remote PM sources will provide a regulatory compliance solution for visible emissions from sources for environmental studies, industrial and military applications.