Fire Detection and Alarm Systems Ch. 2

Sends and receives signals from alram systems and detection devices.

Restricst flow of smoke by an air handling system

Activates alarm when products of combustion are detected

Indicates a condition in fire protection system that is off-normal.

Indicates power failure or system malfunction in fire protection system.

Alarm only notifies occupants of the building.

Poice or Fire must be manual notified by occupant.

Acitivates all alram signalling devices simutaneously.

Notifies responders of a specific "zone" where the fire is located.

Indicates specifically which device was activated.

Continuously monitored alarm system.

EXAMPLE: An alarm company

Local energy: Has its own power supply, does not depend on power from municipal fire alarm system.

Shunt-type: Depends on the power supply from municipal fire alarm system.

One fixed location monitoring multiple occupancies on the same property.

EXAMPLE: College campus

Fixed location continuously staffed that recieves alram signal and notifies the fire department communication center

Alarm signal is transmitted over a leased telephone line to a 24-hour staffed communications center

Verbally alerts the occupant of the problem and verbally tells them what action to take

Telephones mounted in occupancies that allow firefighters to communicate with the incident commander when radio signal is not available.

Usually installed in high rise structures. 

Notifies all occupants, or community of dangerous situations and provides instructions.

Continuously monitors the buildings atmosphere for any unsafe levels of heat, gas, smoke, etc.

Set to activate when a certain temperature inside a structure is reached.

Usually 135 degrees F.

Connecting device that melts when introduced to heat.

Small glass bulb filled with a predetermined amount of gas that expands when exposed to heat that breaks and activates alarm.

Two types of metals with different expansion rates are bonded together, when heat is exposed the strips bend in an arch and complete the activation circuit.

Designed to lose electrical resistance when exposed to heat, increasing the electrical current and activating the alarm.

When exposed to heat, wire insulatioin melts and the two wires make contact completing the circuit and activating the alarm.

Activates when temperatures increase by 12-15 degrees F per minute.

Beam of light shines through the detectors chamber, when smoke interferes with the light beam the alarm is activated.

Two electrically charged plates (+/-) uses radiation to  make the air in the chamber conduct electricity.

Smoke blocks ionized particles and reduces electrical current, activating the alarm.

• Water Vapor
• Carbon Dioxide
• Carbon Monoxide
• Hydrogen Chloride
• Hydrogen Cyanide
• Hydrogen Fluoride
• Hydrogen Sulfide