@inproceedings{ZahoranskySaierLaileetal.2001, author = {Richard A. Zahoransky and T. Saier and Edgar Laile and Michail S. Nikitidis and Athanasios G. Konstandopoulos}, title = {Optical Multiwavelength Technique Applied to the Online Measurement of Particle Emissions from Engines}, series = {SAE: Technical Papers}, volume = {2001}, number = {September}, publisher = {SAE}, issn = {2688-3627}, doi = {10.4271/2001-24-0074}, year = {2001}, abstract = {The importance of obtaining simultaneous particle size and concentration values has grown up with continuing discussion of the health effects, of internal combustion engine generated particulate emissions and in particular of Diesel soot emissions. In the present work an aerosol measurement system is described that delivers information about particle size and concentration directly from the undiluted exhaust gas. Using three laser diodes of different wavelengths which form one parallel light beam, each spectral attenuation is analysed by a single detector and the particle diameter and concentration is evaluated by the use of the Mie theory and shown on-line at a frequency of 1 Hz. The system includes an optical long-path-cell (White principle) with an adjustable path length from 2.5 to 15 m, which allows the analysis within a broad concentration range. On-line measurements of the particulate emissions in the hot, undiluted exhaust of Diesel engines are presented under stationary and transient engine’s load conditions. Mean particle diameters well below 100 nm are detected for modern Diesel engines. The measured particle concentration corresponds excellently with the traditional gravimetrical measurements of the diluted exhaust. Additionally, measurements of particle emissions (mostly condensed hydricarbons) from a two-stroke engine are presented and discussed.}, language = {en} }