Re: Help on alarm

[Robert L Bass <sales@xxxxxxxxxxxxxxxxxxxxx>]

> 1.	Can dual tech pir/motion sensors be installed
> in the same room one opposite to the other or this
> is likely to be a cause of false alarms?...

With modern dual technology detectors this is not a problem.

> I was planning to put a sensor at the opposite
> corners, just above each window.

You may find corner mounting more effective.  Aim the detectors
across the middle of the room but don't allow the PIR zones
(fields of view) to see the windows themselves.  This will
further reduce the likelihood of false alarms.

> 2.	My basement has four windows at garden level,
> all with iron exterior shutters and bolts. I plan to,
> specially in the summer, leave all the windows opened
> and the shutter closed. Is it worth to contact the
> windows or the shutters?

That may help.  There's another way to protect basement windows
which may, depending on the way the windows are framed (inset or
flush), prove useful to you.  There's a device called a BB-1GS
Barrier Bar which looks from the outside like it's a metal window
bar.  In fact, it's a pressure sensitive switch that will trip
the alarm if someone tries to dislodge it.  I've used a number of
these for many years and they hold up well.

The bar functions whether the window is open or shut.  The cable
is covered in a BX-like, flexible sheath to resist tampering.
With a bit of effort these can do a decent job of protecting
basement openings.  However, nothing is 100% so consider backing
them up with a motion detector or two.

> The basement will have DGP2-70 or maybe DGP2-60,
> since I do not have pets living in the house.

I haven't tried those though I've sold well over a thousand of
the wired DG-75 models.  They rarely cause any problems.

> 3.	in the basement I also have a 2.30 tall and 2.60
> meters wide glass sliding door, giving access to the
> garden; the frame is made of iron, the glass is
> bullet-proof and very thick...

If it truly is bullet proof, contact the door against opening and
don't worry about the glass itself.  Besides, if you back it up
with motion detection they're not likely to get by the system.

> The installer said that this glass if repeatedly beaten
> with an heavy hammer, the point beaten would
> crush but the whole glass would not break in peaces,
> so it would not be quicker for a burglar to open himself
> a passage than breaking a standard bricked s wall...

I wonder how much that slider cost.  Attack resistant glass is
expensive stuff.

> Which sensor I should I use to protect it?

Use a wide gap, magnetic "contact" (door sensor) to detect
movement of the door itself.

> I am not sure about glass sensors; I do not think they
> would of any use since I leave windows open; maybe
> an acoustic/vibration detector to detect tampering
> attempts on the shutters and the bullet-proof glass
> could be more useful...

Might be, but from your description of the door it's probably a
wasted expense.

> 4.	I plan to put some DG85 sensors in the garden for
> extra perimeter protection; I am afraid that sensors
> could detect cars or people outside the fence.

Just angle the detectors slightly down so they don't see past the
fence.  I've used plenty of DG85 detectors and they work well,
even during some of the storms that hit south Florida.

> The fence is made of 4 centimetres wide iron bars, with
> 10 cm. of space between each bar. Anyway, I am
> planning to cover the fence with ivy, but this will take
> some time.

We planted jasmine along our fence.  The plants were about 18"
tall from the nursery.  It took year and a half to fill in.  Now
the fence is completely hidden by green leaves and in the spring
the air fills a wonderful jasmine aroma.

Regards,
Robert L Bass
www.BassBurglarAlarms.com


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Regards,
Robert L Bass
http://www.bassburglaralarms.com