A high-dosage, Landsverk Model IM-93/PD, pocket dosimeter. This quartz-fiber dosimeter is typical in size (11.5 cm long by 1.3 cm diameter) of many other pocket dosimeters but is unusual in its useful range. Typically, personal pocket dosimeters are used to record maximum radiation dosages of 200-500 mR. This unit, developed for civil-defense applications during the “Cold War”, has a maximum indicated dosage three orders of magnitude higher, namely 600 R. It should be noted that the lethal dose for humans (50% death within 30 days of exposure) is 25% lower than this maximum dose. This dosimeter was sold to the public from the Diefenbunker near Ottawa. The bunker was built as an underground bomb shelter during the Cold War.
