Diesel Particle Scatterometer

Description:
The diesel particle scatterometer (DPS) characterizes the size distribution and composition of ambient aerosols.

Broad Fields of Use:
Particulate diesel exhaust represents a potential breathing hazard to workers in many industries. Better instrumentation is needed to determine the characteristics of diesel particulates in various types of occupational settings. Industry uses diesel engines for a variety of purposes, and particulates from the diesel exhaust are an important factor influencing the health and safety of industrial workers.

Diesel particulate exhaust has been declared a carcinogen by the state of California but much is still unknown about the long-term effects of exposure to diesel particulates. Better knowledge of the composition, size distribution, and density of these aerosols will allow a more realistic evaluation of mitigation measures to insure worker health and safety.

Comparison with Current Technologies:
There is no single commercially available instrument on the market capable of rapid and convenient measurements of the characteristics of these particulates. The diesel particle scatterometer is capable of determining the size distribution and carbon content of aerosols in diesel exhaust streams.

We know that particulates originating from diesel exhaust continually evolve from the time they leave the combustion chamber through the exhaust system, and further transform with time. More needs to be known about the evolution of the characteristics of these diesel particles–the size, and organic or inorganic carbon content of these aerosols. To better evaluate the potential effects of these particles, measurements are needed of their size and composition.

Description of Current Application:
We have developed a dedicated instrument for the real-time sizing of diesel exhaust particles to study particle characteristics as a function of engine type, load, revolutions per minute, fuel composition, and post-combustion processes (after treatment, dilution, etc.).

The diesel particle scatterometer performs rapid, in situ measurements of the size distribution and optical properties of exhaust from both new, cleaner and older diesel engines. The new instrument shows good sensitivity and discrimination of the diesel exhaust for various running conditions and using different dilution ratios.

Figure 1. Lab prototype of the diesel particle scatterometer.

An important advantage of the instrument is its rapid response time; it has been tested at a greater than 1-Hertz data acquisition rate. This rapid response allows for the measurement of particle characteristics during changing loads and provides data on real-time particle loading during individual firing events.

Contact and Brief Bio:

Arlon Hunt, Senior Scientist
Phone: (510) 486-5370
E-mail:

MS 70-108B
Microstructured Materials Group
Lawrence Berkeley National Laboratory
Berkeley, CA 94720