A radioactive gas injector for the calibration of air monitoring systems

The description of the injector system, the calibration results and calibration factors are discussed. The ratio static efficiency (standard beta disc sources at fixed geometry) to dynamic efficiency was dependent on the energy and the geometry. Four our geometry these ratios are constant (4580 and 5630 respectively for 133 Xe and 11 C). By making some assumptions, calibration factors for other energies can be determined by a measurement of the static efficiency. Lastly, the total uncertainties in the calibration factor for a determined activity were estimated to be less than 10% and approximately 20% for determining air activity concentration