• 

The stations of the Atmospheric Pollution Monitoring and Forecasting Network (XVPCA) are distributed by:
- Know the evolution of air quality levels over time and in the territory.
- Inform citizens of the state of air quality and its evolution.
- Undertake clean-up actions if necessary.
- Prepare maps of vulnerability and capacity of the territory
- Comply with the current regulations on the protection of the atmospheric environment.
- Locate sources of pollutants.
The stations have specific sampling equipment that takes samples to measure the concentration of certain pollutants.
There are manual ones, which are devices that allow you to obtain a sample that is later analyzed in a laboratory. Pollutant concentration levels are not obtained in real time. In addition, the results inform us of average values in a day and not of the peak values that can be important and that occur in shorter periods of time.
There are also automatic ones (or analyzers), which analyze the sample continuously, meaning that increases in contamination can be detected instantly and the results are sent directly to the data receiving center, which allows an action very fast if necessary. Not all substances can be measured with automatic methods and often, such expensive procedures are not necessary. The data generated are stored in the station's computer and transferred to the headquarters of the control center.
In this air quality control macrostation, or supersite, a larger structure than the usual pollution monitoring booths distributed throughout the city, the levels of regulated pollutants are measured (sulphur dioxide -SO2-, nitrogen dioxide -NO2-, carbon monoxide -CO-, tropospheric ozone -O3-, particles with a diameter of less than 10 microns and 2.5 microns -PM10 and PM2.5-, benzene -C₆H₆-, metals, polycyclic aromatic hydrocarbons -HAPs-, and black carbon) and added those for the determination of ultrafine particles, those for chemical speciation of particles in real time, and analysis of sulfates, nitrates, ammonium -NH₄-, organic compounds and metals .