Mobile Source Emissions Testing

This Chapter provides broad review on emission testing of new and in-use vehicles, particularly in the United States. Under a mandate from the U.S. Congress, the U.S. Environmental Protection Agency (US EPA or EPA) sets emissions standards for vehicles. All of EPA's emission regulations specify test procedures to measure engine or vehicle emission levels. EPA uses the test results to determine compliance with the applicable emission standards and also develop emission models such as the MOBILE model and its successor MOVES model. The Clean Air Act (CAA) requires every engine and motor vehicle within the chain of commerce in the United States to meet a set of emission standards and conformity requirements. Various testing for regulatory compliance have been summarized, for example, federal test procedure, testing for inspection and maintenance, emission testing with onboard portable emissions monitoring systems and, testing for special purpose emissions study. Keywords: dynamometer; global positioning system; onboard diagnostics; portable emission measurement systems; remote sensing devices