pressrelease | 2015-09-23

Breakthrough for measuring traffic emissions with new samplers

A fifth of all municipalities in Sweden exceed the threshold for nitrogen dioxide stipulated in the environmental quality standard. But long-term measurement of nitrogen oxide levels at street level is costly and resource demanding. Now IVL can offer air quality monitoring with a new type of diffusion sampler.

After many years of research, IVL is now able to measure levels of nitrogen monoxide and nitrogen dioxide (the so-called NOx gases) using diffusion samplers – small, rugged instruments that can withstand exposure to all types of weather. The sampler does not require electricity to operate, is not reliant on other external devices and can be sited in a wide number of locations to map noxious emissions. – Our NOX sampler is an outstanding addition to established measuring instruments and complements these favourably. You can position a hundred of them over a larger area to obtain distributed samples over time, which gives you an excellent picture of concentration levels and trends, says Martin Ferm, the innovator behind the sampler. Whenever combustion takes place, nitrogen monoxide is formed. This then oxidizes, creating nitrogen dioxide, which is hazardous to health. Traffic is the major source of these emissions that can irritate the respiratory system, but above all nitrogen oxide indicates the presence of other toxic air pollutants. Since NOx is such a good traffic pollution indicator, it can be used to estimate emission factors for particles along a particular stretch of road. The sampler consists of a tube open at one end and is equipped with two impregnated filters. One of these absorbs nitric oxide (NO) and the other nitrogen dioxide (NO2). The sampler can also be used in an indoor environment. IVL’s diffusion samplers are in great demand worldwide. They are small and easy to use and are able to measure the incidence of all common air pollutants. Up until now it has been difficult to measure NOX accurately due to poor performance of the absorption filters previously used. For more information, please contact: Martin Ferm,