You need to readout your personal dosimeter at least once per month at one of the reader stations installed at a large number of locations around CERN. Regular readout is essential to ensure the periodic monitoring of your personal dose. The monthly readout is also required by the Swiss and French Authorities. To assign a correct monthly dose value, you should read your dosimeter at the beginning of each month. If you are absent during the first week of a month or for a longer period, you must however ensure that your dosimeter is read. For longer absences (> 1 month), you should return the dosimeter to the Dosimetry Service.
The dosimeter is activated before accessing a Controlled Radiation Area using an operational dosimeter reader station. After exiting the area a new readout must be done in order to deactivate the dosimeter. This action sends the measured dose value to the Operational Dosimetry Database. If you don't use your dosimeter for more than 1 month, you will be requested to bring it back the the Dosimetry Service.
The map below shows the location of the personal dosimeter readers (red squares, DIS) and operational dosimeter readers (violet squares, DMC). Just zoom in or search for your building and you will easily find the reader station nearest to you.