Calibration of an air monitor prototype for a radiation surveillance network based on gamma spectrometry

• Deficiencies of a commercial air monitoring system are detailed.
• Gamma spectrometry introduction is the basis of the new prototype.
• Efficiency calibration procedure is described for aerosol and gaseous fractions.
• MDA is evaluated for different isotopes and acquisition times.

The objective of this work is to present the improvements that have been made in quasi-real-time air radioactivity concentration monitors which were initially based on overall activity determinations, by incorporating gamma spectrometry into the current prototype. To this end it was necessary to develop a careful efficiency calibration procedure for both the particulate and the gaseous fractions of the air being sampled. The work also reports the values of the minimum detectable activity calculated for different isotopes and acquisition times.