Choosing Devices - Urmet 1068 Série Mode D'emploi

2.3.4

Choosing devices

Choosing the devices to be used in the alarm system means having a clear idea of what they do and how they do it. If
there should be any doubts, it could be useful to read paragraph THE DEVICES USED TO CREATE AN ALARM
SYSTEM.
2.3.4.1 The detectors

Magnetic contacts are used for the doors. For security doors and other metal objects, magnetic contacts with
stronger magnets are used. Glass doors, without safety glass or bars, may resemble windows when deciding which
detectors to use.

Windows are somewhat complicated to protect. Luckily, there are different types of detectors available, so it is
always possible to find a solution for any situation.
If the window has a roller, a cable detector for rollers can be used. If there are shutters, a magnetic contact can
protect them.
A simple window with glass, if not adequately reinforced or protected by a roller or shutter, may require the
contemporary use of a detector for breaking glass and a magnetic contact. For shop windows and skylights,
breaking glass detectors are used.
The windows can then be protected with IR detectors with a barrier or curtain; in both cases the attempt to pass
through the "space" of the window is detected rather than the attempt to force the closure of the window.

For closed environments, volumetric detectors are used. The choice between IR and microwaves can be made
according to contingent factors. If the room to be protected is subject to intense and sudden changes of
temperature, then using IR may result in a greater number of false alarms. Another aspect to take into consideration
when choosing among various model is the roof area and its shape. If the environment is very big, just one
volumetric detector may not be sufficient.
It is better to understand that using multiple microwave detectors in the same room may create problems of
interference among them. These problems do not exist when passive IR detectors are used or when passive IR
detectors are used with a microwave detector.

Once the selection of detectors is complete, it is necessary for their number and type be coherent with the final
project to be created. It should suffice to ask a few simple questions: is there at least one sensor that protects each
door or window in the perimeter protection? If a trap protection was selected, is there at least one volumetric
detector covering each important room? Are all the mandatory passages, like stairways and corridors, covered by an
adequate detector?
2.3.4.2 Sirens

Plan for at least one keypad, regardless of the arming/disarming system of the alarm system adopted;

If the complex to be protected encompasses multiple separate buildings, or if it is very extensive, or there is no
façade that is more visible than the others, then it would be better to take into consideration the installation of more
than one siren.
2.3.4.3 Keypads, readers, and remote controls

Plan for at least one keypad, regardless of the arming/disarming system of the alarm system adopted;

The presence of a keypad allows, for example, entry into the home or office even if the electronic key or remote
control has been lost (remember that for security reasons, it is preferable to keep the keys and electronic
keys/remote controls separately), or to provide service personnel or employees only the entry keys. Moreover,
obviously, this allows the programming of the system and the display of system messages.

It is opportune to install a keypad or reader near every point of access from outdoors. This makes use of the alarm
system much more convenient.

The same consideration should be made if, in a rather large building, there are indoor areas that are physically
separated from others that are identified as an alarm system zone and are always under protection. Even in this
case, a keypad or a reader will be installed nearby.
DS1068-017 17 LBT20717