Development of a Test Method to Measure “In-use ” Emissions from Stationary and

A cost-effective, accurate and an easy-to-use in-field test method was developed that would allow regulatory bodies, such as the California Air Resources Board (CARB) to determine in-use compliance with emission standards for newly manufactured portable and stationary engines. Engine-dynamometer/chassis dynamometer tests have been shown to be unrepresentative of actual in-field operation of the engine; hence, emissions measured during such conditions do not faithfully reflect real-world emissions. Engines may be compliant with certification standards during an engine-dynamometer test, but may still deviate from the standard by two times during an actual “in-use ” operation. Hence, a test method that functions like an Inspection and Maintenance (I/M) type test method (serves as a “screening tool”) and is capable of measuring in-use emissions from portable and stationary engines was developed. Only concentration measurements of pollutants such as oxides of nitrogen (NOx) and carbon dioxide (CO2) are required to determine compliance using this “Compliance Factor, F ” approach. Hence, errors introduced due to engine work output measurement and exhaust flow rate measuremen