Fire alarm systems

A fire alarm system warns people when smoke, fire, carbon monoxide or other fire-related emergencies are detected. There are two types of fire alarm initiating devices: manual and automatic.At the core of a fire alarm system are the detection devices, from sophisticated intelligent smoke detectors to simple manually operated break glass units, there are a wide array of different types, but we can divide them into groups including:
– Heat detectors
– Smoke detectors
– Carbon Monoxide detectors
– Multi-sensor detectors
– Manual Call Points

1. Fire alarm
systems

2. ANASEEM HANINI
DR.MONTHER KRESHAN
Al-Balqa' Applied
University.

3. Fire Alarm System is designed to
alert us to an emergency so that
we can take action to protect
ourselves, staff and the general
public.Fire alarms are found in
Offices, Factories, and public
buildings, they are a part of our
everyday routine but are often
overlooked until there is an
emergency at which point, they
might just save our lives.

6. WHATEVER THE METHOD OF
DETECTION IS, IF THE ALARM IS
TRIGGERED, SOUNDERS WILL
OPERATE TO WARN PEOPLE IN
THE BUILDING THAT THERE MAY
BE A FIRE AND TO EVACUATE

11. IONIZATION
LIGHT SCATTERING
LIGHT OBSCURING
1.
2.
3.

12. IIonization Smokeonization Smoke
DetectorDetector
Ionization Smoke detector generally
contains two chambers. The first is
used as a reference to compensate
for changes in ambient temperature,
humidity or pressure.
The second chamber contains a
radioactive source, usually alpha
particle, which ionizes the air
passing through the chamber where a
current flows between two
electrodes.
When smoke enters the chamber the
current flow decreases. This drop in
current flow is used to initiate an
alarm.

15. The light scattering smoke
detector operates on the Tyndall
effect; a photocell and light
source are separated from each
other by a darkened chamber such
that the light source does not
fall on the photocell.
The passage of smoke into the
chamber causes the light from the
source to be scattered and fall on
the photocell. The photocell
output is being used to initiate
an alarm.

17. In the Light obscuring smoke
detector, smoke interferes with a
light beam between a light source
and photocell. The photocell
measures the amount of light it
receives.
The variation in photocell output,
is being used to initiate an alarm.
This type of fire detection
equipment can be used to protect
large areas with the light source
and photocell positioned some
distance apart.

19. Carbon Monoxide
Carbon Monoxide
Detectors
Detectors
Carbon monoxide detectors are
known also as CO fire detectors
are electronic detectors used to
indicate the outbreak of fire by
sensing the level of carbon
monoxide in the air.
CARBON MONOXIDE IS A POISONOUS
GAS PRODUCED BY COMBUSTION.
Carbon monoxide detectors have an
electrochemical cell, which senses
carbon monoxide, but not smoke or
any other combustion products

21. Multi-Sensor Detectors
THE MULTI-SENSOR DETECTORS
COMBINE INPUTS FROM BOTH
OPTICAL AND HEAT SENSORS AND
PROCESS THEM USING A
SOPHISTICATED ALGORITHM BUILT
INTO THE DETECTOR CIRCUITRY.
it is used in small house

23. A Manual Call Point or Break
Glass Call Point is a device
which enables personnel to
raise the alarm by breaking
the frangible element on the
fascia; this then triggers
the alarm.

26. 1. CONVENTIONAL
FIRE ALARM
SYSTEMS
2. ADDRESSABLE
FIRE ALARM
SYSTEMS

27. The biggest difference between
conventional and addressable fire
alarms is scale. Conventional fire
alarms are ideal for small
buildings, such as individual
offices or retail shops. They go
off individually when they detect
smoke or heat and will help
everyone escape from your building
safely and quickly.

28. Addressable fire alarms are a
necessity for large building
complexes or campuses.
Addressable fire alarm systems
are typically more expensive
than conventional alarms, but
the extra information they
provide to firefighters and
building managers is invaluable.

29. A heat detector is a device that can
sense heat in a room. Its purpose is
to alert homeowners and business
owners that there is a fire before
the fire becomes irreversible. The
device responds to convected thermal
energy radiated from a fire.

31. There are two main types of heat
There are two main types of heat
detectors:
detectors:
FIXED TEMPERATURE
DETECTORS
When the strip is heated by
fire, the high-expansion
side bends the strip toward
an electrical contact. When
the strip touches that
contact, it completes a
circuit that triggers the
alarm to sound. The width of
the gap between the contacts
determines the temperature
that will set off the alarm.

32. RATE-OF-RISE HEAT DETECTORS
Commonly Heat detectors work in a similar way to an electrical
fuse, the detectors contain a eutectic alloy which is heat
sensitive when a certain temperature is reached the alloy turns
from a solid to a liquid which in turn triggers the alarm.

34. https://www.hunker.com/12615082/notifier-fire-alarm-troubleshooting
https://www.covesmart.com/blog/how-a-heat-detectors-works/
https://realpars.com/fire-alarm-system/
https://www.slideshare.net/MahmoudElrahman/ss-81683676
https://www.orulo.com.br/a/americov/4182
REFERENCES

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