How do smoke detectors work?

Question

I read this [https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/smoke-detectors.html](https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/smoke-detectors.html) but I need help 😛

In: 3

Answer 1

There’s a little bit of radioactive metal (usually Americium) in a chamber which releases a little bit of radiation, and a detector which sees this constant little bit of radiation. When smoke fills the room with the detector, some smoke gets into this radioactive chamber and absorbs/deflects the radiation coming off the metal. When the detector starts to “see” less radiation (because it’s being blocked by smoke), it starts the alarm ringing.