The DustTrak™ II and DustTrak™ DRX Aerosol Monitors are battery-operated, data-logging, light-scattering laser photometers that provide real-time mass concentration readings for aerosol contaminants such as dust, smoke, fumes and mist. From desktop and desktop with external pump models to handheld models, DustTrak™ Aerosol Monitors offer a suitable solution for harsh industrial workplaces, construction and environmental clean-up sites, as well as clean office settings, with the DRX models being the only laser photometers on the market that can measure mass and size fraction simultaneously. Also, an environmental enclosure accessory is available to allow for protection of the desktop models to permit 24/7 outdoor monitoring regardless of the weather conditions and in harsh industrial environments.