The dose rate of external radiation is measured by an automatic external-dose rate-monitoring network maintained by STUK and local rescue services. The network comprises about 255 stations. Each monitoring station has its own station-specific alarm level which is the average of the previous seven days’ dose rate and added by 0,1 µSv/h. Measurement data is stored in the national data system. There they are available for several authorities almost in real time. The daily measurement data of automatic stations are displayed on these www pages. The rescue services have more than 100 stations where external radiation is monitored locally. Authorities have thousands of portable meters too. They are important as supplements to the automatic network. They are used for verifying the results of the automatic network as well. In Finland, external radiation varies from 0.05 to 0.30 microsieverts per hour (µSv/h). During the Chernobyl accident in 1986, the highest momentary dose rate measured in Finland was 5 µSv/h. It is necessary to shelter indoors if the external dose rate exceeds 100 µSv/h. Page updated 22/06/2010 |
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