Challenges of Measuring Low PM10 and PM2.5 Emissions From Stationary Sources

Abstract Description: The measurement of particular matter emissions from stationary sources traces to the promulgation of EPA Reference Method 5 in August 1977. Today, depending on how you count them, there are approximately 20 particulate measurement methods that vary to reflect the type and size of particulate matter being measured. Although all particulate measurement methods offer challenges, the proper measurement of PM2.5 from stationary sources is technically challenging and critically important given the recent promulgation of a 9 ug/m3 National Ambient Air Quality Standard (NAAQS) for PM2.5. This presentation will review the technical challenges associated with measuring PM2.5 emissions by examining the different methods for measuring PM2.5. The examination will include advantages, disadvantages, and known and potential limitations of the various measurement options. Concepts of primary and secondary Particulate Matter emissions will also be discussed to demonstrate the principal challenge of PM measurement from stationary sources. When measuring particulate matter in the ambient air, the particulate has already formed and can be measured at "actual" conditions. When it comes to source testing, some assumptions must be made about how much particulate matter will be converted to a liquid or a solid upon cooling in the atmosphere near the emission point. Most current test methods attempt to simulate the conditions upon cooling, but the methodology is far from perfect.