OPSIS - DOAS Products for Gas Analysis
Differential Optical Absorption Spectroscopy (DOAS) is the core technology in the OPSIS product portfolio, where a combination of light transmitters, light receivers, optical fibres, and analysers enable the measurement of gaseous pollutants in ambient air.
The Monitoring Path - Emitter and Receiver
The DOAS technology is based on the emission of white (broadband) light in a narrow beam from a xenon lamp (emitter) and its capture by a receiver. Along the beam of light, which can be several hundred metres long, different types of pollutants absorb different wavelengths of light. It is this absorption that is measured in the analyser. The open beam of light is also called the monitoring path because that is where the monitored concentrations of air pollutants are found. OPSIS offers several different products to form the monitoring path.
Complete and Flexible Systems
A basic system for monitoring gas concentrations in ambient air consists of an analyser, an emitter/receiver set or a combined emitter/receiver and reflector, and an optical fibre cable that transmits the light to the analyser. The system can be configured to measure a wide range of gaseous compounds. A single analyser can monitor concentrations along several different monitoring paths. All in all, this provides a complete monitoring system that is both versatile and cost-effective. Read more on the page on turnkey solutions. It is possible to supplement an existing system with the monitoring of additional substances and on more monitoring paths.
Tested and Approved
The OPSIS DOAS systems have been tested and approved by several international test institutes and national authorities, including the U.S. EPA and the German TÜV.