The IM 201M monitor forms part of the RAMSYS™ product line.
It has been developed to continuously measure the gamma volumetric activity of radioactive iodine sample, in both molecular and organic forms (methyl iodine), contained in air drawn from stacks, ventilation ducts or working areas. An NaI scintillation detector faces the activated charcoal cartridge in which radioactive iodine is trapped. The proximity of the detector and the cartridge, enclose within a 4 π/5 cm (4 π/2 in) lead shielding, serves to optimize detection efficiency.
A radioactive 241Am source built into the NaI chrystal allows compensation of temperature and aging related drifts. The spectrometry capability, based on a 1024 channel spectrum analysis, allows radio iodine isotope localization.