Particulate Matter Measurements in a Diesel Engine Exhaust by Laser-Induced Incandescence and the Standard Gravimetric Procedure

Laser-induced incandescence has emerged as a promising technique for measuring spatially and temporally resolved
particulate volume fraction and size. Laser-induced incandescence has orders of magnitude more sensitivity than the
gravimetric technique, and thus offers the promise of real-time measurements and adds the increasingly desirable size
and morphology information. Particulate matter emissions have been measured by laser-induced incandescence and the
standard gravimetric procedure in a mini dilution tunnel connected to the exhaust of a single-cylinder diesel engine. The
engine used in this study incorporates features of contemporary medium- to heavy-duty diesel engines and is tuned to
meet the U.S. EPA 1994 emission standards. The engine experiments have been run using the AVL 8-mode steady-state
simulation of the U.S. EPA heavy-duty transient test procedure. Results of the measurements using the two methods are
compared and the suitability of the laser-induced incandescence for particulate mass measurements in diesel exhaust is
demonstrated.