Particulate Measurement Program - Light-Duty Vehicle

This page last reviewed February 7, 2012


Background

Particulate matter (PM) from diesel engines has been shown to cause adverse health effects and has been designated a Toxic Air Contaminant (TAC) by the ARB. In California, the first DPM emission standard for heavy duty engines was implemented in 1988 at a limit of 0.6 g/bhp-hr. Since that time 1988, the standard has been tightened and as of 2007 the standard is 0.01 g/bhp-hr. In California, the LEV II standards for light duty vehicles also require passenger cars (gasoline or diesel) to emit less than 0.01 g/mile for the first 120,000 miles of operation. Similar steps have been taken in Europe where the EURO1 standard was introduced in 1992 and required diesel passenger cars to emit less than 0.14g/km of PM and EURO5 PM standard will take effect in 2008 at setting standard for both gasoline and diesel passenger cars to 0.005 g/km.

Those PM emission standards are mass based. PM emissions are measured by collecting them on filter media and weighing them. The detection limit of this procedure is severely challenged by emissions meeting the US07 and EURO5 standards. There is a need to explore new systems for the measurement of PM emissions. A promising methodology for measuring PM is counting particles, which may be significantly more accurate and precise at very low emission levels than the gravimetric method. Europe has launched an extensive, multi-nation research initiative under the auspices of the United Nation's Economic Commission for Europe - Group of Experts on Pollution and Energy (ECE-GRPE or UN-GRPE) to study this issue. The program is called the Particulate Measurement Programme (PMP) and is under the direction of Joint Research Center (JRC) of European Commission's Directorate General in Ispra, Italy. The result of this significant work has been the development of instrumentation and methodologies for counting of solid particles in vehicle exhaust emissions. The JRC concluded that "The particle number measurement procedure is suitable for regulatory use" (GRPE-PMP-17-1, Ispra, September 12, 2006).

Extensive testing of the newly proposed PMP sampling protocol has been underway in Europe and Asia to verify the applicability of the proposed methodology to light duty vehicles. Specifically, a single vehicle, called the Golden Vehicle, or GV has been shipped to laboratories in Italy, Sweden, United Kingdom, Germany, Greece, Japan, Korea and France in a round-robin testing exercise. The Golden Vehicle (GV) is a Peugeot 407 Saloon 2.0 HDi 136 SE equipped with an uncoated diesel particulate filter and cerium based fuel borne catalyst. A set of particle counting instruments, the Golden Particle Measurement System (GPMS), have been sent along with the vehicle as has in most cases the 'Golden Engineer' who has helped with initial setup of the instrumentation. Results so far indicate that the particle number measurement is 20 times more sensitive than the mass measurement (GRPE-PMP-15-2, Geneva, May 31 2005).

ARB Testing

The GV was sent to Los Angeles for testing at the ARB' Haagen Smit Laboratory--the first testing of this vehicle in a US laboratory. The testing will be beneficial to the JRC by providing another important data point for its inter-laboratory correlation exercise. ARB is gaining important practical experience with the PMP methodology and a unique opportunity to compare results with laboratories around the world.

ARB has conducted a number of emission tests to study various issues. The studies include: mean emission rates and variability of emission rates at ARB compared with European laboratories; emission rates over US driving cycles compared with emission rates over European driving cycles; the effect of differences in US and European soak times and preconditioning procedures on emission rates. In addition, a test of evaporative emissions was conducted on the GV, which as typical of diesel fueled vehicles, has no evaporative emission controls.

The testing has been completed and the results are currently being compiled into a report for ARB and JRC review. Conference presentations and a technical report will be available soon.


References

Results

  • Alberto Ayala et al., (October, 2008). California's Informal Participation in the Particle Measurement Programme (PMP) Light Duty Inter-laboratory Correlation Exercise (ILCE_LD). ARB Research Final Report (PDF - 2,652KB)

Conference Presentations

  • 18th CRC On-Road Emissions Workshop, March 31 - April 2, 2008, San Diego, CA
  • Sherry Zhang et al., Final Results from CARB's Evaluation Testing of the European Reference Vehicle from the Particulate Measurement Program. Presentation (PDF - 1,738KB)
  • 11th ETH International Conferences on Combustion Generated Nanoparticles, August 12-15, 2007, Zürich
  • Alberto Ayala et al., A California Preliminary Assessment of PMP for Determination of Diesel Particle Emissions. Presentation (PDF - 5,793KB)
  • 17th CRC On-Road Emissions Workshop, March 26-28, 2007, San Diego, CA
  • Alberto Ayala et al., Emissions Measurements from the Golden Vehicle - A Light Duty Diesel Vehicle Used during Validation of the European PMP Protocol. Presentation (PDF - 3,631KB)

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