The Analytical Facility Core has excellent capabilities in the area of aerosol sampling and measurement. Capabilities include direct reading and filter measurement of mass and number concentra-tion; measurement of particle size distribution over the size range from 10 nm to 30 µm; measurement of particle size distributions as a function of number, mass, or mass of a specific chemical; the ability to generate solid and liquid aerosols; and several chambers and tunnels for simulating aerosol exposures for calibration and validation.

A GCA (MIE) RAM-1 respirable aerosol monitor and a TSI Piezobalance provide direct-reading capability for field measurement of mass concentration. The TSI Porta-count portable battery-powered condensation nuclei (CN) counter provides direct reading of number concentration in the field. To measure size distributions, there is a PMS LAS-X Optical Particle Counter (0.15 to 7.5 µm), a TSI Model 3310 Aerody-nam-ic Particle Sizer (0.5 to 30 µm), and six types of cascade impactors, including several Marple Personal Cascade Impactors and an MSP rotating-stage Micro-orifice Uniform Deposit Impactor (MOUDI) (0.08 to 25 µm).

The new Particle Instrumentation Unit (PIU) of the EPA Particle Center provides access to sophisticated ambient air pollution instruments including real-time aerosol size distribution measurement instruments. Instruments in this unit include continuous monitors for carbon monoxide, nitrogen oxides, and ozone, a Tisch Environmental Hi-Vol sampler with a PM-10 inlet, a TSI aerodynamic particle sizer (APS), two MSP ten-stage micro-orifice cascade impactors, a MOUDI, PM-10 and PM2.5 samplers, a TEOM continuous PM-10 sampler for non-volatile particulate matter, a MIE DataRam, and a TSI scanning mobility particle spectrometer (SMPS) (10 nm to 1 µm).

The ability to generate aerosols under controlled conditions is important for testing, calibration, and validation of aerosol sampling and measuring instruments and methods. To simulate aerosol exposures and processes in the laboratory there are two Wright dust feeders, three NBS dust feeders, and several types of nebulizers. The Unit has a bench scale respirator testing chamber, a spray booth/tunnel testing system, and a dual-port smoking machine for generating mainstream or side-stream cigarette smoke under realistic conditions. For simulating large particle inhalation and sampling, we have a unique specially designed low velocity wind tunnel which allows direct measure-ment of these phenomena with a life-size full torso mannequin under carefully controlled condi-tions of air motion and particle size.