urmet domus 1067/024, Руководство по установке

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DS1067-063D
36
LBT20064
3.3.3 How to protect areas and people
The purpose of an intrusion alarm system is to prevent some prowler from accessing the areas to be protected without
him noticing the system. This means monitoring openings and passages, which lead to two different techniques:

The
“perimeter" protection
, where detectors are installed in all the openings (entry doors, windows, skylights, and
glass doors) on the exterior of the areas to be protected. The detectors must cover the entire perimeter: even one
single, small, and seemingly insignificant opening that is not monitored represents a protection shortcoming and
makes it a potential point of entry for intruders. The advantages of this solution are that the alarm is given as soon
as someone attempts to enter and that it is possible to arm the system even if there are people in the rooms; the
disadvantage is that if the intruder success in entering without setting off the alarm, it is no longer possible to detect
him and he may act without consequences.

The
“trap” protection
guarantees that the most important rooms and passages (like corridors and stairways, etc.)
are surveyed. The advantage of this solution is that the intruder may not wander about undisturbed, in that sooner or
later his presence would be detected; the disadvantages are that when his presence is detected, he has already
entered and it is not possible to arm the alarm system with people inside the rooms.
Figure 6 - Perimeter and trap protection
The best and most versatile protection is obtained, obviously, by using both technique. In paragraph
The subdivision into
zone this will be explained. Protecting the same room with more than one type of detector, when technically and
economically possible, is a good idea because it increases the probability of discovering an intruder.
In particular situations, like a building surrounded by a garden, it is even possible to consider a form of "advanced"
protection, in the sense that is constitutes a confine of protection in front of and remotely from the actual areas to be
protected, seeking to anticipate potential intrusions as much as possible. A typical example are the detectors installed
along the gates or the perimeter walls of a garden or outdoor courtyard, but they might also be seismic detectors
installed along a driveway within the property.