Development of the primary measurement standard for gaseous radon-222 activity

The Korea Research Institute of Standards and Science (KRISS) has developed a primary system for the activity standardization of gaseous radon-222, based on the defined solid angle counting method. The size of adsorbed radon is determined by a Cyclone Storage Phosphor System, and a buffer chamber is introduced between the measurement chamber and the source for the purpose of gas purification. The measured activity of gaseous radon-222 and its associated measurement uncertainty obtained using the system are presented.

► KRISS has developed a primary system for gaseous radon-222 standardization.
► The KRISS system is based on the defined solid angle counting method.
► The size of deposited radon is determined by a radiosensitive phosphor system.
► A buffer chamber is introduced for the purpose of radon gas purification.