perimeter detectors

[bernardgreen]

Is it possible to get a single beam sender & receiver with a mirror to reflect the beam?

Yes it is BUT with a simple break beam system using a mirror if the object ( person ) to be detected is also reflective then the reflection from the object may be enough to false the receiver into thinking the beam has not been broken.

More complex systems using a mirror can measure the length of the beam and if it is shortened by a reflective object then the receiver will indicate a detection. Smae princle as lase measuring devices.

Less complex method is for the sender to have filters to pass only vertically polarised IR energy and the receiver to have filters that accept only horizontally polarised IR energy. The mirror has optics which rotate the polarisation from vertical to horizontal

 

[DRM]

Where could I buy this equipment from?

TIA

 

[Gees]

Might sound a bit simple but why not just turn on the chime function for your outside doors. It wont stop them from cutting their way in but will alert you when the door opens. Probably send them scuttling away too.

 

[DRM]

So far I’ve found this

https://www.ultrasecuredirect.com/w...a-driveway-perimeter-alarm-004-0500-p567.html

or this

http://www.ebay.co.uk/itm/Seco-Larm...663903?hash=item1c5b8715df:g:nicAAOSwYHxWKRqQ

What do you reckon?

 

[sparkymarka]

No.... If you have to buy one with a reflector .... Look on security warehouse "takex pr 11b " £80 plus vat

 

[DRM]

Thanks for that, it looks good, but I would have preferred one with a greater range.

Is this about the limit for one with a reflector?

One with a 25m range would be ideal for what I have in mind.

 

[sparkymarka]

If you want more than that , don't even consider one with a reflector, you may find one but be careful as the range may be the indoor range , not external in most cases it half !

 

[simonpolly]

Surely if you lock the window handle locks this would solve your problem (unless they cut a huge circle in the glass). Also if you fail to lock the handles on your windows this normally voids your home insurance if they break in via the window.(see cillla black)

 

[ross94]

Surely if you lock the window handle locks this would solve your problem (unless they cut a huge circle in the glass). Also if you fail to lock the handles on your windows this normally voids your home insurance if they break in via the window.(see cillla black)

thats a very good point, my windows are double glazed and most are locked. I don't think the poor buggers last summer had the windows locked. so the thief just cut a small circle in the glass enough to get his arm in and open the window and that was it, he's in. And if the windows were locked, most people have a very nasty habit of leaving the keys in the window again easy access for the burglar, just like leaving your car keys near the front door or back door. I have been guilty of that myself but thankfully never payed the price for it. I always warn my friends and family about that now.

 

[simonpolly]

Surely if you lock the window handle locks this would solve your problem (unless they cut a huge circle in the glass). Also if you fail to lock the handles on your windows this normally voids your home insurance if they break in via the window.(see cillla black)

thats a very good point, my windows are double glazed and most are locked. I don't think the poor buggers last summer had the windows locked. so the thief just cut a small circle in the glass enough to get his arm in and open the window and that was it, he's in. And if the windows were locked, most people have a very nasty habit of leaving the keys in the window again easy access for the burglar, just like leaving your car keys near the front door or back door. I have been guilty of that myself but thankfully never payed the price for it. I always warn my friends and family about that now.

You can only do so much if the toerags are determined enough they will get in,lock the windows and leave a key or keys near by so you can unlock them in a emergency and make sure all family members know where the key is.