1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Smoke detectors

  1. Aug 23, 2004 #1
    I just noticed my new $10 smoke detector contains a few microcuries or less of radioactive Americium. Anyone one knows how these work? Why this element? It's the first time I see an application for it.
  2. jcsd
  3. Aug 23, 2004 #2
    Google search string: smoke detector radiation yields this among the search results

    I don't know why that element; probably it is cost efective and safe.

    Keep on chuggin !!

  4. Aug 23, 2004 #3
    If I remember correctly, Americium is pretty much the lowest decay of radiactivity. It emits quite a bit of alpha waves. There is a sensor that picks up the alpha waves, and thus the smoke detector doesn't ring. When the smoke is there, the waves are scattered, and thus it rings :)

    It was a project I did quite some time ago, so I'm not sure if I'm completely right. Feel free to correct me.
  5. Aug 23, 2004 #4
  6. Aug 24, 2004 #5
    Thank you guys. Fun to see those funky elements are good for something.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook