File:Radioactive Smoke Detector - Americium 241

English: This video shows very low levels of radioactivity that escape from an ionization-type smoke detector that contains 0.9 microcuries of radioactive Americium 241 (according to the label). A simple Geiger counter with a Pancake probe is used for the measurements.
If you look at other YouTube videos, you can see that the tiny americium source is intensely radioactive -- perhaps even too radioactive to be measured with this type of geiger counter, since it would overwhelm the geiger tube. Only a tiny fraction of that radioactivity passes through the case and escapes from the smoke detector.
I did not disassemble the smoke detector, since it had to go back up on the ceiling after the video.

Notes: This is a plug-in type smoke detector, with battery backup. The battery was removed for this video, since the smoke detector complains about being unplugged.