TSI DUSTTRAK™ II and DRX Aerosol Monitors are batteryoperated, data-logging, light-scattering laser photometers that give real-time aerosol mass readings. They are great for industrial hygiene surveys and investigations, as well as for remote long-term unattended sampling applications. DUSTTRAK Monitors measure aerosol contaminants such as dust, fumes, smoke and mists. TSI, Inc., www.tsi.com, (800) 874-2811.