On Sun, Apr 16, 2017 at 9:33 PM, Tom Metro <tmetro+hhack...@gmail.com> wrote: > Greg Rundlett wrote: >> I bought a house 6 years ago, and I was perplexed this week as ALL the >> First Alert combo smoke + CO detectors started chirping and went bad. >> The First Alert smoke detectors have and "End of Life" feature... > > As Federico pointed out, this is due to the limited lifespan of the sensor.
[Pure speculation on my part] I can imagine sensors which might last a very long time when not being used but have a finite life when activated. Perhaps using chemicals that are aerosolized when warmed (by electricity). Without knowing the actual physics/chemistry involve in the sensor component itself, this all seems like speculation to me. As others have said, this is a relatively inexpensive safety item for a very expensive asset, Bill Bogstad _______________________________________________ Hardwarehacking mailing list Hardwarehacking@blu.org http://lists.blu.org/mailman/listinfo/hardwarehacking
