4 ms·

Next time buy optical smoke alarms, they are better [1] and don't contain radioactive materials. [1] https://m.youtube.com/watch?v=DuAeaIcAXtg&t=1196s&pp=ygUWc

• js2 4y ago
  I went with three First Alert SC7010B, one per floor, which are photo electric and detect both smoke and CO. For the rest of the alarms I used First Alert 9120B which are ionizing. I figure I covered all my bases that way. I think they have a life span of a decade so it'll be a while before I need to replace them again.