Monitoring Background Levels

Air pollution at regional and national scales

It is important to monitor air pollution where many people stay, i.e. in cities and especially at street level. In order to better understand where the pollution comes from, a so-called background monitoring may also be needed. Then the monitoring station is placed in the countryside, at a great distance from obvious sources of the pollution.


By monitoring background levels of air pollutants, it is possible to distinguish locally created pollutants from those imported from other regions or countries. An important tool for this mapping is the collection of meteorological parameters such as wind speed and wind direction. The monitoring stations for background concentrations are therefore often complex with many different types of monitoring equipment.

The monitoring of background levels places special demands on the monitoring equipment. On one hand, the equipment must be able to monitor low levels of pollution with high accuracy, and on the other many different types of pollution have to be monitored, some of which are not prioritised when monitoring in cities. For practical reasons, the equipment must also be reliable and require minimal maintenance.

OPSIS offers such monitoring systems. In addition to monitoring traditional pollutants such as sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and PM10 and PM2.5, the instruments can also be configured for monitoring, for example, nitric acid (HNO2), nitrogen trioxide (NO3), formaldehyde (CH2O), and methane (CH4).


There are multiple reasons for choosing OPSIS as supplier of systems for gas analysis. Among the key benefits of the methods and solutions offered by OPSIS are:

  • high data availability
  • cost-effective, non-contact technology with open monitoring path
  • representative data
  • gas calibration only once a year
  • low energy consumption
  • long maintenance interval
  • certified by German TÜV, U.S. EPA, and others. 


OPSIS Open-path DOAS

OPSIS Data Services

OPSIS Monitoring Services

Contact Henrik T OPSIS 720X480pxl

Contact me if you want to know more about systems for monitoring background levels!