Re: Unguarded conduits--The unheralded hero of scifi adventure!

"Anim8rFSK" <ANIM8Rfsk@[EMAIL PROTECTED]
> wrote in message 
news:ANIM8Rfsk-B9A0F9.15091525012008@[EMAIL PROTECTED]
> In article <479a4b38$0$36405$742ec2ed@[EMAIL PROTECTED]
>,
> "James Gassaway" <dtravel@[EMAIL PROTECTED]
> wrote:
>
>> Anim8rFSK wrote:
>> > In article <479a2f8f$0$36322$742ec2ed@[EMAIL PROTECTED]
>,
>> > "James Gassaway" <dtravel@[EMAIL PROTECTED]
> wrote:
>> >
>> >> Anim8rFSK wrote:
>> >>> In article <4798ed22$0$36374$742ec2ed@[EMAIL PROTECTED]
>,
>> >>> "James Gassaway" <dtravel@[EMAIL PROTECTED]
> wrote:
>> >>>
>> >>>> PV wrote:
>> >>>>> Anim8rFSK <ANIM8Rfsk@[EMAIL PROTECTED]
> writes:
>> >>>>>> Probably heat detectors.  Take a piece of tape, and see if you
>> >>>>>> can walk right up to it and tape it over.
>> >>>>>
>> >>>>> Nope, not a heat detector. You can push open the door with a
broom
>> >>>>> and the lights will go on.
>> >>>>
>> >>>> As I recall, motion detectors work by detecting air movement.  So
>> >>>> if you move slowly enough to not generate significant air
>> >>>> displacement, you're fine.  But that was some years ago and tech
>> >>>> changes fast these days.
>> >>>
>> >>> My motion detectors are looking for heat.  We also have glass break
>> >>> (noise) detectors.  I'm not sure how a motion detector would look
>> >>> for air displacement unless it was looking at heat?
>> >>
>> >> A really sensitive pressure sensor?  Moving air exerts pressure on
>> >> the sensor, triggering it.  I don't think I ever was told the
>> >> details and it was some time ago.  *shrug*  (And, no, they couldn't
>> >> be used outdoors because the wind would trigger them.)
>> >
>> > You'd think that would be triggered by the A/C cycling.
>>
>> That could have been a problem too, which may help explain why everyone
>> thinks they don't make those anymore.
>
> Yeah.  They might have worked in some more temperate clime, where the
> A/C isn't on unless people are moving around anyway, but not in Arizona,
> where it cycles all day struggling to keep up.
>
> -- 
> Jitterbug phones:
> Fourth one is in hand.  Doesn't work.  Again.
> Billing is all wrong.  Again.
> Avoid at all costs.

Wouldn't sonar fit the bill?

-- Ken from Chicago