Publicité
Telephone lines
If telephone lines are used to transmit alarms, they may be out of ser-
vice or busy for certain periods of time. Also an intruder may cut the
telephone line or defeat its operation by more sophisticated means
which may be difficult to detect.
Warning devices
Warning devices such as sirens, bells, horns, or strobes may not warn
people or waken someone sleeping if there is an intervening wall or
door. If warning devices are located on a different level of the res-
idence or premise, then it is less likely that the occupants will be alerted
or awakened. Audible warning devices may be interfered with by
other noise sources such as stereos, radios, televisions, air conditioners,
other appliances, or passing traffic. Audible warning devices, however
loud, may not be heard by a hearing-impaired person.
- 4 -
Publicité
