Re: Humans invisible to heat sensors?

[Frank Olson <Use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx>]

Roselnathan wrote:
> Thanks for all (constructive) replies!  Frank - No, detector not
> by-passed, it's one of those systems where you only have the option of
> setting Zone A (Ground floor inc exterior doors) or whole house - no
> refinements liked auto-bypass on offer.  Zone A  was fully armed from
> time they set it to time they switched off and when the break-in
> scenario was re-enacted alarm went off immediately every time.  Rocky -
> definitely not wearing checkered suits (neighbours saw them running to
> car)  Crash - didn't want to bore the world with exactly what was done
> when/floorplan but no, not that stupid.  Cheers.
>
> Frank Olson wrote:
>
>>Roselnathan wrote:
>>
>>>Anyone heard of clothing or other device which makes an intruder
>>>invisible to heat-sensing type of sensor (part of domestic security
>>>sytem)?  (1) Last night friends activated ground floor zone at 11.45pm.
>>>(2) Approx 2.55am burglars threw paving stone through ground floor
>>>window, got in and left with 42" HD plasma TV - alarm did not go off.
>>>(3)  Owners woken by noise, went downstairs, switched off system at
>>>3am.  Today alarm professionally tested and apparently working OK.
>>>Print-out shows 1 and 3, no activity of any kind between.  What
>>>happened?  Vague hint that there are ?clothes ?devices that make the
>>>wearer/user invisible to these sensors.  About to take up expensive
>>>contract with national name (UK) and would appreciate advice.
>>>
>>
>>
>>If they were *home*, chances are the detector was bypassed.  You should
>>check if the "auto-bypass" or "stay" feature is enabled.  If you arm the
>>system and don't leave and can walk in front of the sensor without
>>setting off the system then "auto-bypass" is enabled.  To arm the sensor
>>you have to open and close the main exit door.  If the system is
>>monitored, please ensure that you call the station before you do any
>>testing.
>
>


I recommend the addition of a glass break detector in the room with the
window they broke.  If a motion sensor is close by (within the coverage
area of the glass break), you can mount it next to the PIR and avoid
having to run a lot more wire.  If there are extra zones available on
the system and the zone common is shared, you could wire it in such a
way as to have seperate zones for the glass break and the PIR and still
use the same four conductor already home run to the panel.

If your client is going to replace the TV through insurance you should
advise him that in some cases the perps wait for two or three weeks and
then repeat their original break-in to steal the replacement.  I don't
know what your client will do when the alarm goes off at 0230 in the
morning and the crooks are actually *in* the premises.  The glass break
detector will activate the alarm *before* they can actually gain entry
(as soon as the window is smashed).  It may be enough to discourage them
from coming in but you never know.  I would definitely have the system
monitored.  Consider some form of backup in case they compromise the
telephone lines too.