Review of Diesel Particulate Matter Sampling Methods Final Report

.........................................................................................................................3 INTRODUCTION ................................................................................................................5 DIESEL ENGINE TECHNOLOGY AND EMISSION REGULATIONS .............................7 PHYSICAL AND CHEMICAL NATURE OF DIESEL AEROSOL .....................................9 AEROSOL SIZE DISTRIBUTION.....................................................................................11 DIESEL AEROSOL DYNAMICS ......................................................................................13 Diesel Particle Dynamics and Behavior ............................................................................13 Particle-Wall Interactions Losses of Particles to Sampling Surfaces ...............................13 Particle Dynamics and Transformations............................................................................15 Effects Of Test Conditions on Diesel Aerosol ..................................................................16 Dilution and Saturation Ratios .........................................................................................17 Engine Emission Characteristics.......................................................................................21 Residence Time ...............................................................................................................22 On-Road Exhaust Dilution...........................................................................................23 Laboratory Exhaust Sampling Dilution.........................................................................23 INSTRUMENTS FOR MEASUREMENT OF DIESEL PARTICLE MATTER..................24 Critical Aerosol Parameters .............................................................................................24 Instruments Used to Measure Diesel Aerosol Size Distributions.......................................25 Summary of Particle Measurement Instruments................................................................27 EVALUATION OF ROADWAY, TUNNEL, AND OCCUPATIONAL TEST METHODS 29 EVALUATION OF DIESEL TEST LABORATORY METHODS......................................40 Exhaust Constituents .......................................................................................................41 Emission of Carbonaceous Agglomerates and Volatile Material ...................................41 Ash Constituents in Exhaust.........................................................................................46 Exhaust Sampling Conditions ..........................................................................................48 Relative Humidity and Temperature of Dilution Air .....................................................48 Dilution Ratio and Residence Time ..............................................................................49 Conclusions .....................................................................................................................50 RECOMMENDATIONS ....................................................................................................50 SPARK IGNITION (SI) MEASUREMENTS .....................................................................51 FUTURE RESEARCH........................................................................................................53 ACKNOWLEDGEMENTS.................................................................................................54 BIBLIOGRAPHY...............................................................................................................54