The Scintrex 209L Tritium-In-Air monitor was developed at Chalk River and then packaged and sold commercially by Scintrex. Two ionization chambers along with the associated electronics are housed in the 20 cm long by 13 cm wide by 10 cm high metal box. Both ionization chambers have a volume of 80 cubic centimetres. Both are sensitive to gamma rays, the closed chamber being used to compensate for the gamma-ray background. The meter has an operating range from 10 microcuries of tritium per cubic metre to 20 000 microcuries per cubic metre.
