Pictures and radiation measurements

"Radiation measurement" here means count rate at a certain distance. It as measured using a small window-type geiger tube and an analog rate-meter. Readings are in Imp/min, and are only approximate of course.
Watch from the 1950s, dial plate with radium paint marks. At 5cm distance 400/min with front glass, 1000/min without.
Gas lantern mantle, thorium doped. At 5cm distance 400/min.
Luminous badge from WWII, worn by persons walking on the street during "Verdunkelung" (i.e. no light allowed to make not a good aim for bombs). Estimated activity in the radium paint is 70kBq. At 5cm distance 20,000/min. (!)
Thorium nitrate as it can be bought from chemical supply stores. Nominal activity 165kBq (50g). At 5cm distance 800/min.
Smoke detector from Great Britain, where these are very common. The pictures show different stages of disassembly. In the first picture, the black plastic cylinder on the right contains the ionisation chamber. The metal plate at its top has a warning message on it. the second picture is a close-up of the ionisation chamber. The Americium-241 source (activity 37kBq) is at the centre.

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Jochen Kronjaeger