Acoustically Excited Inertial Tympanum Particulate Matter Nanobalance

Improving particulate matter (PM) analysis technology for on-vehicle measurements remains a significant challenge. The requirement for accurate and highly precise real-time measurement, capable of on-vehicle applications, is rapidly increasing. Expanding demand for compliance measurements, and assessing and evaluating engine performance development and emergent exhaust aftertreatment technologies, are driving this growth. Systems that currently are available and under development require skilled personnel, have short filter life spans, and fail to provide the necessary speed and precision for transient operational measurements on new, clean diesel engines. Optical and electrostatic systems exist that offer fast and continuous measurements; however, they do not satisfy the criterion of direct mass measurement. The required measurement precision will exceed microgram capabilities as manufacturers strive to achieve compliant emissions levels for the 2007 regulations and beyond. A significant need currently exists for an on-vehicle, autonomous PM measurement system that can provide continuous measurements over protracted periods of time. Analytical Engineering, Inc. (AEI) proposes to develop a nanogram-resolution, 1-second sampling measurement module that operates on the basis of filter membrane inertial measurements through acoustics. The Phase I research project will focus on the mechanical structure and acoustic measurement technologies necessary to interpret and extract acoustic signatures as a function of PM mass accretion on the filter membrane. The development of this technology into a commercial product will result in an autonomous, continuously operating, on-vehicle and/or laboratory PM measurement system that is capable of resolving 1-second timeslice incremental mass accumulation. The system operation is based on filter media and the associated hardware for conventional PM filter measurements; therefore, the technique correlates to and is relevant to existing procedures.

Commercialization of this technology initially will target modeling, inspection and maintenance, and industrial engine and after-treatment manufacturers. The largest market exists in industrial applications ranging from diesel engine performance development to vehicular applications where packaging for exhaust aftertreatment and other auxiliary subsystems for the engine are required. AEI will market this system as both a stand-alone unit and as an optional module to its existing product line of on-vehicle emissions measurement systems.