Re: Correct Placement Of IR

["The Pig" <pig@xxxxxxx>]

I really apprecaite it.  Thanks.



"Bob Worthy" <securinc@xxxxxxxxxxxxx> wrote in message
news:Eisxg.18381$ZH1.3000@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> "The Pig" <pig@xxxxxxx> wrote in message
> news:9%rxg.5001$Mz3.3722@xxxxxxxxxxxxx
>> Wondering what the correct placement of IR sensors are.  For isntance,
> let's
>> say you have a room that is a perfect square, 20 by 20.  Now, the north
> wall
>> ahs a large window on it and the east wall has a smaller window on it.
>>
>> Are you suppose to face the the IR sensor in the corner of the south west
>> wall pointed at the direction of the two windows or would you face the IR
>> detector in the corner of the north west wall facing away.
>
> Actually the Northeast corner with following manufacturers specs on height
> from floor. Watch air vents, both feed and return. Don't let the motion
> look
> at reflective items ie mirrors, chandeliers, etc. If all this exists and
> you
> can't get away from it, consider audio discrimination as an alternative.
>
>> I guess what I'm not sure of is are you trying to sense somone entering
> the
>> window befroe they get all the way in the house or when they have already
>> got int he house.
>
> ASAP without creating built in false alarm issues
>
> I'm not clear on if there are issues facing an IR sensor
>> at a window where sunlight might be, someone passing the window on the
>> outside might set it off, etc.
>
> By asking this question, you have a pretty clear picture.
>
>> Sorry if this is a stupid question, just now real clear on what the
> "right"
>> way is.
>
> Most standard detectors have a field of view of approx. +/- 90 degrees. By
> placing the detector in the corner, the field of view will be passing in
> front of the windows and not looking directly at the windows. You may have
> to watch curtain movement when window is open and zone is bypassed for
> what
> ever reason or what air conditioning/heat circulation may do to the
> curtains. This field of view will cover what ever the specs are on your
> motion. Most motions would cover a 20X20 room in its entirety.
>
>