Re: Daylight Savings
(Americium / ionisation)
Point taken - I'm no chemist :-)
Mains alarms - fitted these when I rewired a previous house. Rate-of-heat-rise in the kitchen, smoke (optical) elsewhere. Never a false alarm, tested as well as I could (difficult for the RoH) and changed the batteries every two or three years. Cheap (see my previous links) and simple.