How does RIVM measure air quality?
That happens continuously. Both with professional measuring equipment and with the help of amateurs. RIVM has sixty official measurement points. They measure the particulate matter concentration in the air every hour. Then there are also about 2,500 people who measure particulate matter with a cheaper device. These devices cost about fifty euros, but they do give a good picture of the particulate matter concentration.
RIVM combines this information and thus obtains a fairly detailed picture of the particulate matter concentration. A map is made of this that shows how the particulate matter is developing throughout the Netherlands.