Analytics supplies mixed and single radionuclide gamma-ray standards for airborne radio-iodine determinations. The calibrated radionuclide solution is gravimetrically dispensed and evaporated on activated charcoal or silver zeolite then is sealed in the customer's canister or cartridge. The activity can be deposited on the first 3 to 5 mm of the charcoal or zeolite material to simulate the distribution found in actual samples (face-loaded) or homogenously loaded throughout the cartridge to calibrate for "flip" counting applications. A thorough discussion of the measurement of airborne radio-iodine can be found in D.M. Montgomery's paper, "Calibrating Germanium Detectors for Assaying Radio-iodine in Charcoal Cartridges", Radioact. Radiochem, 1(2),4, (1990).

Charcoal or silver zeolite canister or cartridge standards can be prepared using Analytics' mixed gamma-ray standard or using single radionuclides such as ¹²⁵I or ¹³¹I. In applications where gamma-ray coincidence summing is not a problem ¹³³Ba can be used. For more information on coincidence summing see "The Counting Room: Special Edition" referenced previously.