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

[mbbaker@xxxxxxxxx]

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.


Frank Winans wrote:
> I'm a computer geek, and am about to discard
> another cheap ionization smoke detector that
> has gotten too sensitive to put up with.  Cleaning
> the little chamber didn't help much, though yes,
> that often worked in years past, on other units
> I've had.
>
> Actually, I'm thinking of tweaking the sensitivity
> with unauthorized do-it-yourself circuit mods.
> I'll want to destroy the unit before I let it fall into
> another's hands, but I'll accept the increased
> risk of myself dying in a home fire that using
> such a device entails.  Maybe I'll disguise it as
> an abstract sculpture or something, so nobody
> else would ever come to rely on it to detect
> smoke ;-)
>
> But this brings up some issues;
>
> a) how can I properly calibrate it, and later
> retest it, using actual smoke?  Like using a
> measured amount of tobacco on a red-hot
> heater, and ducting that into a known volume
> trash bag or box... I've never seen this topic
> discussed, and wonder if the old TEST button
> is a credible witness of sensitivity, now that I
> think about it...
>
> b) If this works out, should I ever admit it to my
> friends?   We're all just a few degrees away
> from the most monstrously inept/stupid/deranged
> person one might ever envision, and I'd be
> enabling that "friend of a friend of a friend" to
> construct a passively hazardous device {or
> large assemblage of same.}
>
> c) And why doesn't there seem to be any prior
> postings on this HOWto ?  Do they get
> censored by somebody eventually?   Sure, it
> may be <unwise> to discuss in a public forum,
> from a strictly personal-legal-liability standpoint,
> but that wouldn't normally prevent the topic arising,
> judging from the blatantly unwise / illegal things
> I see out on the internet already. {Porno sites,
> prescription drugs offered by correspondance. Ech!}