Evaluation of the Proposed New European Methodology for Determination of Particle Number Emissions and ITS Potential in California for In-Use Screening

摘要

The European countries have developed new methodologies for the measurement of 'solid' particle number above a size cut threshold of 23 nanometers (nm) to compliment gravimetric measurements at low particle levels typically found with energies and vehicles equipped with diesel particle filters (DPFs). This methodology provides significant improvements in significant improvements in measurement sensitivity, but should be fully understood in terms of the representativeness of the particles, which are only solid and > 23 nm in size, their adverse health effects, and the repeatability of the measurement. The California Air Resources Board (CARB) sought to enhance the understanding of the PMP methodology and to develop well-informed opinions regarding its application. The specific objective of this study was to critically evaluate the proposed PMP method for determining 'solid' particle number emissions from heavy-duty vehicles in the laboratory and during over-the-road driving. For this program, testing was conducted on the chassis dynamometer at the CARB heavy-duty vehicle emissions laboratory in Los Angeles and over the road with the CE-CERT mobile emissions laboratory (MEL). One or two PMP dilutions systems for measuring solid particle number were tested and compared directly with filter-based PM measurements on two heavy-duty trucks equipped with a DPF.