Particulate Sampling and Measurement
Near-real-time measurements are made for particles ranging in size from 0.5 to 30 µm using an aerodynamic particle sizer (APS) manufactured by TSI, Inc. The primary advantages of this system are the high resolution and the short sampling time. To determine the concentration of submicron particles (0.01–1.0 µm), a scanning mobility particle sizer (SMPS), also manufactured by TSI, Inc., is used. The SMPS system consists of two primary sections: an electrostatic classifier and a condensation particle counter (CPC). The purpose of the electrostatic classifier is to remove a predictable fraction of the particles within a narrow size range and pass these on to the CPC where the particles are counted. The CPC measures particle number concentration by using the light-scattering technique. This instrument can be used independently of the electrostatic classifier as a continuous real-time monitor of the number of fine particles that are present in the flue gas.

Instruments for Particle Sizing
The following testing services are available through the PRL:

• APS – Laser-based design that counts and sizes individual particles.
• CPC and SMPS – Uses the submicrometer dust particles as a condensation nuclei to form a droplet large enough to count with a laser counter; particle-size separation is provided by an electrostatic classifier. When the CPC is used in conjunction with computer-controlled software, a near-real-time particle-size distribution can be determined.
• Multicyclone and impactors – Provide a size cut from a sample withdrawn from the stack isokinetically, which may not provide enough sample for some analytical techniques.
• High-volume, three-stage source assessment sampling system – Provides a size cut on high-volume samples.