The Particle Technology Laboratory is one of the leading centers of small particle research in the U.S. PTL is well-known for its instrumentation development activities. Instruments for particle generation, measurement, sampling and analysis in the range of 0.002 to 100 µm have been developed. Research has been incorporated into codes and standards by NIST, ASTM, ASHRAE, EPA, and ISO, etc. Major facilities of the Laboratory include 15,000 square feet of general laboratory space, and 500 sq. ft. of class 100 cleanroom space; wind tunnel, filter testing, and vacuum facilities; instruments for particle generation, measurement, sampling and analysis in the 0.002 to 100 µm diameter range; and microscopes, electron microbalances, gas analyzers, anemometry and other laboratory instruments. The estimated value of the laboratory instrumentation is in excess of $3 million. The Laboratory also offers an annual Aerosol and Particle Measurement Shortcourse for training professionals from industry, university and government laboratories.