[HH] CO detectors self-destruct

[Bill Bogstad]

On Sun, Apr 16, 2017 at 9:33 PM, Tom Metro <tmetro+hhacking at 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