12
Smoke Alarm
The smoke alarm monitors the air for combustion particles that
are produced when something is burning or smoldering. When
combustion particles in the smoke sensor reach a specified
concentration, the alarm/voice message warning system will sound,
and be accompanied by the flashing red LED.
The smoke alarm takes precedence when both smoke and
carbon monoxide are present.
NFPA 72 states: Life safety from fire in residential occupancies is
based primarily on early notification to occupants of the need
to escape, followed by the appropriate egress actions by those
occupants. Fire warning systems for dwelling units are capable of
protecting about half of the occupants in potentially fatal fires.
Victims are often intimate with the fire, too old or young, or
physically or mentally impaired such that they cannot escape even
when warned early enough that escape should be possible. For
these people, other strategies such as protection-in-place or assisted
escape or rescue are necessary.
Smoke alarms are devices that can provide early warning of
possible fires at a reasonable cost; however, alarms have sensing
limitations. Leading authorities recommend that both ionization and
photoelectric smoke alarms be installed to help ensure maximum
detection of the various types of fires that can occur within the
home. Ionization sensing alarms may detect invisible fire particles
(associated with fast flaming fires) sooner than photoelectric
alarms. Photoelectric sensing alarms may detect visible fire particles
(associated with slow smouldering fires) sooner than ionization
alarms.
A battery-powered alarm must have a battery of the specified type,
in good condition and installed properly.