UV Beam Identifies Invisible Air Pollutants

Air pollution used to be something you could see and smell. But as air quality standards have tightened, the air over most industrial sites, airports and cities has gradually cleared. Nevertheless, invisible toxic agents such as ethyl benzene, butadiene and styrene continue to pose risks to public health. With a view to detecting and quantifying these agents, Siemens Environmental Systems Limited in Poole, England has introduced UV Falcon. The system consists of a transmitter that projects a UV (ultraviolet) beam generated by a deuterium lamp across an open path of between 10 – 200 meters to a receiver. Based on the principle that gases have characteristic “spectral fingerprints,” or in other words absorption lines in the 200 – 300 nanometer UV range, the system uses a patented fourier transform spectrometer to scan the beam for up to 20 toxic and environmentally harmful gases in low parts per billion levels. Although the majority of applications are for fixed installations, the Environment Agency of England and Wales recently purchased a Falcon system for rapid mobile deployment.