Instrument Development for Real-Time Measurement of Particulate Concentration and Primary Particle Size in Diesel Engine Exhaust Using a Novel Implementation of Laser-Induced Incandescence

In the 2002 Small Business Innovation Research Solicitation, the U.S. Environmental Protection Agency explicitly expressed interest in instruments that can accurately and reliably measure particulate emissions from vehicles. The availability of suitable instruments for measuring particulate emissions from engines and vehicles will benefit two broad categories of users: (1) it will directly help in the development of low emission engines, and (2) it will allow the appropriate government agencies to establish roadside checkpoints for monitoring the particulate emissions from vehicles and take enforcement actions against violators of environmental regulations. Laser-induced incandescence (LII) has emerged as a technique for measuring soot concentration and size (it appears that non-soot matter is evaporated and/or does not contribute to the signal). In the Phase I proposal, Artium Technologies, Inc., introduced a novel LII method for precisely determining the primary particle size and the number density of primary particles, in addition to particulate concentration in diesel exhausts. The proposed LII technique is capable of real-time particulate matter (PM) measurements over any engine transient operation. LII also has orders of magnitude more sensitivity than the gravimetric technique. The wide dynamic range and lower detection limit of LII make this technique a potentially preferred standard instrument for PM measurements. The Phase I effort clearly demonstrated the capabilities of the LII technique. The Phase I effort established the feasibility of building an instrument using this technique, and the proposed Phase II effort will further develop the technique and instrument as well as verify its suitability for PM measurement in a variety of applications. The Phase II Option effort will focus on cost reduction leading to the development of a roadside monitor as well as a portable version of the LII instrument.