Work for a contractor who replaces them in condos or something. They need to be replaced every 10 years, and with semi modern codes a 2-3 bedroom unit will have 3-5. A 20 unit condo with 4 stories would be 240-400 smoke alarms to replace every decade.
Oh man one time my apt building was being remodeled and they threw everything into a dumpster out back and left for a week. The smoke detectors in the pile were going off randomly all the damn time. I must have smashed 30 of those fuckers against the wall to shut them up.
Would the grain show up in digital pictures as well or only on film? I know why it appears on film but the gnomes that work my cell phone camera won't give me a straight answer.
I’m not even sure it would show up on film either. But for CCD cameras (aka phone cameras and basically all modern cameras), 350 americium buttons buttons from a smoke detector in a wide “stew” that far away would produce nowhere near enough ionizing radiation to do that. On top of it, americium-241 is an alpha emitter, meaning that even if alpha particles reached the lens, the lens itself would block a good amount an alpha. This video gives a demo of a CCD without protection over it with americium and other various emitters :)
Pretty much, but highly dependent on the energy of the ionizing radiation. Lower would come out as a dull grain, higher would show up as bright spots. Neither would look like this post though lol