Low-cost Sensor Applications for Improved Control of Fugitive Industrial Emissions

Researchers, regulators, and industry all seek better ways to characterize and manage air pollutant emissions from spatially and temporally complex sources. Traditional manual leak detection methods and fence line monitoring approaches can identify nonconforming emissions, such as fugitive leaks or malfunctioning industrial processes, but are expensive to implement and carry high temporal latency, limiting detection efficacy. Low-cost leak detection sensor approaches present a cost-effective alternative to conventional methods, but systems must be able to provide accurate and actionable data. To date, sensors such as miniature photoionization detectors (PIDs), show promise in detecting hazardous pollutant emissions at low levels. However, these low-cost sensors are known to have baseline drift and other artifacts that significantly complicate use.

Here we present recent advancements in PID sensor performance for leak detection and fence line applications. The U.S. EPA's open-source, solar powered SPod sensor, which combines stabilized 10.6 eV PID with high-fidelity wind measurements, will be described. The SPod's high sensitivity (~ 10 ppbv) paired with collocated wind and atmospheric measurements allows for continuous signal identification above sensor noise levels and coupled source trajectory attribution for higher impact events. Improvements in emissions detection were accomplished through a combination of sensor thermal stabilization and automated data processing algorithms which separate drift from target signal. Recent field studies, including examples of industrial source detection and triangulation using inverse modeling, will be discussed.