Road traffic measurement
The air quality of the Söderledstunneln, a road vehicle tunnel located in the south of Stockholm city, is measured during summer and winter periods. The measurement equipment is in a room next to the tunnel. Tubes on the wall connect with the tunnel environment, and the measurement devices can continuously sample the air inside the tunnel. The groups from KTH, Stockholm University and SLB-Analys perform the measurements. The representative devices used on this site are DGI, ALI system, ELPI+, SMPS, NOx, Aethlometer etc.
Figure 1. The measurement site at Söderledstunneln.
Underground metro platform measurement
The airborne particle level on the Tekniska Högskolan metro station underground platform is continuously measured. The station is close to KTH’s main campus, and the passenger flow can reach 25500 people per day. The KTH measurement group is the primary maintenance and user of this site. The Stockholm University and SLB-Analys also perform measurements at this site for more dimensions of air quality information. The main instruments are Fidas 200S, DGI, FMPS, ALI system, NOx and Aethlometer etc.
Figure 2. The measurement site at Tekniska Högskolan metro station.
Urban background measurement
The urban background measurement site is on the roof of Maria Sjukhus (a hospital in the centre of Stockholm). This site is mainly maintained and used by SLB-Analys. They have been using this site to measure the Stockholm urban background air quality for years, giving a good baseline of measurement history. The main devices on this site are TEOM, CPC, ELPI+, etc. In addition, the Stockholm University and KTH groups also plan to measure on this site by the ALI system and DGI, respectively.
Figure 3. The Stockholm urban background measurement site.