This Small Business Innovation Research (SBIR) Phase I project will investigate the feasibility of using radio-frequencies to provide a real-time measurement of black carbon emissions. There is a growing demand for black carbon measurement systems in response to increasingly stringent emissions regulations. Accurate measurement and characterization of ambient and source black carbon emissions are hampered by the lack of low-cost and portable measurement systems suitable for use in the field. This information is critical to assess black carbon levels, identify sources, and ultimately reduce emissions. Filter Sensing Technologies plans to utilize radio frequencies to provide a direct, real-time measurement of black carbon. The research will investigate using inexpensive components, similar to those used in cellular phones, ideally suited for use in a portable measurement system. <br/>The broader/commercial impacts of this research are that currently the market for particulate matter and black carbon measurement systems is rapidly outpacing the markets for other types of emissions analyzers. There is a significant unmet need to provide portable, real-time, low-cost measurement systems to monitor these emissions. Recent studies indicate a significant warming potential for black carbon, and have also linked the pollutant to a range of adverse health effects. Regulators and source operators alike require tools to monitor black carbon emissions, ensure in-use compliance, and improve process efficiencies. Currently, few technologies can distinguish black carbon from other types of particulate matter. The proposed technology is well-positioned to capitalize on this growth, providing a robust, portable, and much lower-cost alternative to currently available instruments.