Re: mum's the word on howto tweak smoke detector

["Frank Winans" <fwinans@xxxxxxxxxxx>]

<mbbaker@xxxxxxxxx> wrote
> The only way I'm aware of determining the sensitivity of a smoke
> detector or smoke alarm, is with a calibrated test instrument such as
> those available from SDI and Gemini Scientific.
>
> SDI -> http://www.sdifire.com/trutest.html
>
> Gemini -> http://www.geminiscientific.com/products.html
>
> In the early stages of a fire:
>
> Ionization smoke detection is more responsive to flaming fires, which
> produce ionized particles, and is less responsive to smoldering fires,
> which produce particles that are not ionized.
>
> Photoelectric smoke detection is more responsive to smoldering fires,
> which produce particles of sufficient size to scatter light, and is
> less responsive to flaming fires, which produce particles too small to
> scatter light.
>
>
Thanks!  I love to learn what tools are out there!  I can see
I've got a lot of reading up to do on this stuff.

The description of how an ion chamber works, found at
http://www.epa.gov/radiation/sources/smoke_howdo.htm
indicates the smoke makes neutral the ionized air
created by the alpha radiation, and thus 'chokes off' the
usual electrical current flow through the chamber.  I can see
now how moist air causes false tripping, as it is noted
for eradicating bound static charges.  I suppose pollen can
cause tripping too, as it wastes the available static charges
on somewhat ponderous pollen grains, which only sluggishly
convey the current flow between the two plates.

I'm glad optical systems have progressed;  back in the 70's
I tinkered with a HeathKit unit that was a real disappointment
to me.  But I have a lot of friends that would rather do without
a home detector at all, than spend twice as much for a decent
unit.  So it may be choosing between a cheap ion unit, or nada.

And I understand the professional interest in proper alarm
safety here, but I'm guessing other stupid things we do are a
lot bigger cause of lost lifespan than dying in a nighttime fire.
So yeah, get a good alarm, but don't be smug about it if you're
obnoxious in biker bars, help some gun nut's wife cheat on him,
drive drunk a lot, or do crime for recreation.  Oh, and are
living mostly junk food,  while being a lazy couch potato.