On 7/30/20 1:49 PM, Fred McKenzie wrote:
In article ,
Mercellus Bohren wrote:

do they ever need to be completely replaced?

The fire alarm people say yes. Apparently there is some radioactive
material involved, that deteriorates over several years.

Fred

Ionization smoke alarms tend to respond faster to the smoke produced by
flaming fires than photoelectric smoke alarms. Photoelectric smoke
alarms tend to respond faster to the smoke produced by smoldering fires
than ionization smoke alarms.

Only the former have a radioactive element...

--
Why is it that the people who want more government control over your
life are the same ones who want you to be disarmed?