Development of a calibration system for airborne 131I monitoring devices

A prototype calibration system for airborne 131I monitoring devices was developed at the Shanghai Institute of Measurement and Testing Technology (SIMT). This system consists of a gaseous 131I2 generator, an airborne storage chamber, an airborne iodine sampler, and an HPGe spectrometer. With this system, 131I reference samples in the form of charcoal filters and charcoal cartridges, with activities ranging from 100 to 10,000 Bq, were produced with overall relative standard uncertainties of 2.8% (for filter samples) and 3.5% (for cartridge samples); the activities range could be extended according to need.