From: S.A.McIntyre@durham.ac.uk (Scott A. McIntyre)
Newsgroups: uk.misc
Subject: Re: Alarm systems
Date: 17 Dec 92 18:04:32 GMT
Reply-To: S.A.McIntyre@durham.ac.uk
Distribution: uk
Organization: University of Durham

Graham's response was complete and very accurate, but as having recently purchased an
alarm system, I have a few things to add...

The communicator:  When you have a communicator installed, it is important to note that
you are only allowed 3 false alarms in a six month period before the Police strike your
house of their list of quick response homes.  A neighbour or yourself can still manually
call the police and they are obligated to investigate, but they may not be in any rush.
	If the alarm is triggered by a break-in, PIR disruption, and so on, then no audible
or visible warning will be made for about 10 minutes, which gives the Police time to
arrive to catch the theif in the act.  Not all alarms operate this way, but in my opinion,
it is wise.
	The exception to the above is the Panic Button.  PB's set off all the bells and
whistles you've got, AND phone the police.  However, DO NOT put a PB next to the front
door as if someone is gaining forced entry whilst you are at the door, you are likely to
be pushed back away from the trigger (perhaps mount the PB in a hall or a nearby wall that
you would travel past if you are fleeing.
	Some alarms (mine included) allow a DURESS option.  This means that if someone
follows you into your house, and orders you to turn off the alarm under duress, you can
enter a special code which will phone the police but NOT sound off the alarm.  This could
be wise in life-threatening situations.  Obviously, the duress option only works if you
have a digital communicator installed.
	If your phone line is cut then the bells go off.  British Telecom has introduced a
method whereby such communicators can tell the difference between cutoffs in service (due
to works or storm, etc) and a snipped line.  I can't remember the details, but it has to
do with the line generating a tone the communicator listens for, rather than the line
voltage or current.
	Most alarm companies rent the modem/communicator, rather than sell it to you. 
This is largely to cover their costs of operating the hardware on the other side to
receive it.  You technically own it, but pay an annual rental for the use of it.  This
could be in the area of 100 pounds per year.

PIR:  Pets can be a problem with PIR systems.  If you have a dog, most alarm fitters can
adjust the sensor to avoid a certain level (say about 4 feet).  Keeping in mind that cats
are not effected by gravity, this method will not take care of them.
	Forced air heating sysytems can cause a problem for PIR sensors.  Most clever
installers have ways around this, but make sure that you point you that you have such a
system.
	Draughts can cause problems...we had a few false alarms because of a draughty
front door.  

Buying:  Make sure that you're not just renting your alarm system.  You want to be able to
take it with you if you leave the house.  This costs very little to uninstall, and means
that you have something to keep you secure wherever you are.

Bells:  If you live in a high crime area, or near one, consider a anti-foam alarm.  These
things pump out about 165db of noise.  They are VERY loud.  But, baddies can not cover
them with foam (as they can quieter models) to dampen the sound (well, they dampen a bit,
but only to about 95db, which will still wake Hong Kong).

Other things to consider:  Remote keypads mean that you can have a keypad nearish the
front room / door to activate and de-activate the alarm on entry / exit, and another
keypad in the bedroom means you can easily activate/deactivate when going to bed.
	Plan Ahead!  Just because you only think you've got three rooms doesn't mean you
should be convinced to buy an alarm with only four zones (essentially sensors, PIR,
window, door, etc).  Less zones means less cost, but if you find a future problem area, or
are interested in adding on to the house, it's a good idea to plan for future zone
expansion.

I bought from a local company, Central Security, and was very impressed by their service,
friendliness, and so on.  The big names are good, but you can feel a bit of a number
(which is why I did not give the job to the bigger names, even though some of them were a
bit cheaper).

Good luck!

Scott

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