Particle Leak Sniffer™
Office of Automotive Engineering

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image of graph showing the number concentration of solid particles for an uncracked and cracked DPF

This graph shows the number concentration of solid particles for an uncracked and a cracked DPF. In this example, a small crack in the DPF increased the number of particles by a factor of three for the same engine operating condition.

image of the ultra-high sensitivity particle detection system

An ultra-high sensitivity particle detection system consisting of a dilution system, catalytic stripper, and condensation particle counter, along with the control system. This system is readily adaptable to be used with any combustion source.

The Particle Leak Sniffer™ was launched by Southwest Research Institute (SwRI) to detect solid exhaust particle leaks from high efficiency exhaust particle filters such as diesel particle filters (DPF) and gasoline particle filters (GPF). Particle leaks can be caused by:

  • Filter cracks
  • Canning defects
  • Fuel-borne catalyst particles passing through
  • Other problems

The Particle Leak Sniffer combines particle counting with SwRI's catalytic stripper technology, using a unique dilution strategy. The sensitivity of the method is capable of differentiating particle leaks with equivalent mass of much less than one picogram per cubic meter (<<< 1 pg/m3).

The Particle Leak Sniffer covers particle size ranging from 5 nanometers (nm) to 1,000 nm, detecting more than 99.9 percent of combustion-generated particles. We work with clients to establish a threshold where the leak becomes significant.


The Particle Leak Sniffer is suitable for:

  • Drop-to-idle regeneration testing for filter and canning leaks
  • DPF solid particle number efficiency evaluation
  • DPF inspection and maintenance programs using a defined solid particle concentration threshold
  • Solid particle number emission measurement
  • Other R&D and QA/QC applications

Related Terminology

black carbon  •  particle calibration  •  soot particles  •  particle filters  •  DPF  •  GPF  •  global warming  •  particle inhalation studies

Benefiting government, industry and the public through innovative science and technology
Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 9 technical divisions.