Frequently Asked Questions (FAQ's)

General Questions

What services and products does Bevan Security Systems provide?
Can I upgrade my system at a later date?
How do I get a quote?
Do you have a glossary of terms?
Can I pay my account by Credit Card?
Where are your offices located?
How long has Bevan Security Systems been in business?
Why should I choose Bevan Security Systems?
Is the Bevan Security Systems Central Station U.L.-listed?
How long will it take to install my system?
I am not happy with the system I currently have through another company. Can I switch over to Bevan Security Systems?
My Alarm System was not installed by Bevan Security Systems, can Bevan still monitor it?
Are your systems proprietary? Can they be monitored or serviced by others or do I have to have everything replaced if I become unhappy with your service?
Most alarm companies need to subcontract other companies for parts of the installation that they are not licensed for. Is this a practice of Bevan Security also?

General Alarm System Questions

How much will an alarm system cost?
What is a monitored alarm system?
Should my property or premises be monitored?
Can I get a break on my insurance if I get an alarm system?
What happens if my phone lines are cut?
What happens to my alarm system if the A.C. Power fails?
Do you need a separate phone line for the monitoring portion?
Why does my keypad display “not ready” or not have a green ready light lit?
Am I responsible for testing my system regularly?
Will VOIP work with my security system?
Does a home alarm system really reduce my chance of being burglarized?
What is the difference between Photoelectric and Ionization smoke alarms?
Why does the National Fire Protection Association (NFPA) recommend that home smoke alarms be replaced after 10 years?
How long do the batteries for my alarm system last?
 

Glossary

 
#
2nd Line. A programming option that allows you to use a second phone line to send reports to the central station reciever should the first line fail.

24 Hour Zone. A zone that is not turned on or off by system arming or disarming.

4-2 Communication. A hexadecimal communication format that allows the panel to send alarm and system reports to compatitable recievers. The 4-2 format consists of a 4 digit account number, a 2 digit event code, and a 1 digit checksum.

4 Wire Bus Trouble. A keypad message indicating trouble on the keypad bus. This message is generated when one of the following occur:
  • Two supervised devices on the keypad bus are set to the same address
  • No supervised devices are on the keypad bus
  • Low data voltage on the yellow wire of the keypad bus

BaseT.
The industry standard use of 10-Mbps ethernet over unsheilded twisted pair wire.(Cat5e or Cat6)
 
A
Abort. An authorized system user manually cancels an alarm after an armed zone. Used mainly when the zone trip was accidental such as the opening of an armed door, and a police or fire resonse is not needed.
Abort Report. A report sent by the panel following an alarm report to indicate the alarm has been canceled by an authorized user and no dispatch is required.

AC Line. Power line delivering alternating current.

AC Noise. Electric Noise of a rapidly alternating or pulsating nature. It can interfere with DMP’s data bus in some cases.

Accessible (as applied to equipment). Admitting close approach; not guarded by locked doors, elevation, or other effective means.

Accessible (as applied to wiring methods). Capable of being removed or exposed without damaging the building structure or finish or not permanently closed in by the structure or finish of the building.

Accessible, Readily (Readily Accessible). Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, and so forth.

Accessible Area of Refuge. An area of refuge that complies with the accessible route requirements of CABO/ANSI A117.1, American National Standard for Accessible and Usable Buildings and Facilities.

Accessible Means of Egress. A path of travel, usable by a person with a severe mobility impairment, that leads to a public way or an area of refuge.

Acknowledge. To confirm that a message or signal has been received such as by the pressing of a button or the selection of a software command.

Active Multiplex System. A multiplexing system in which signaling devices such as transponders are employed to transmit status signals of each initiating device or initiating device circuit within a prescribed time interval so that lack of receipt of such signal may be interpreted as a trouble signal.

Addition. An extension or increase in floor area or height of a building or structure.

Addressable Device. A fire alarm system component with discrete identification that can have its status individually identified or that is used to individually control other functions.

Addressable Control Device. A signaling system output device which, when operating with a compatible control unit, is used to control individual preselected electrical circuits such as audible or visual alarm signaling appliances, fan circuits, or door release circuits.

Addressable Intelligent Device. A signaling system data input device which, when communicating with a compatible control unit, may have its status individually identified by the control unit.

Addressable System. A system, which uses a signaling technique that, allows a control unit to identify a specific initiating device or group of devices by location.

Addressable System Smoke Detector. A smoke detector, which, in addition to providing alarm and trouble outputs to a control unit, may be uniquely identified by location to the main control unit.

Adverse Condition. Any condition occurring in a communications or transmission channel that interferes with the proper transmission or interpretation, or both, of status change signals at the supervising station. See also Trouble Signal.

Agent Release. The release of a chemical substance (i.e., Halon, FM200) capable of producing a chemical reaction, which will extinguish a fire. Agent release is most often used in areas where water release would cause damage to electrical equipment.

Agglomerate. To gather into a ball, mass, or cluster.

Air Sampling-Type Detector. A detector that consists of a piping or tubing distribution network that runs from the detector to the area(s) to be protected. An aspiration fan in the detector housing draws air from the protected area back to the detector through air sampling ports, piping, or tubing. At the detector, the air is analyzed for fire products.

Alarm. An Alarm is an audible, visual, or physical presentation designed to warn the instrument user that a specific level of a dangerous gas/vapor concentration has been reached or exceeded

Alarm Initiating Device. A device which when actuated, initiates an alarm. Such devices, dependant upon their type, may be operated manually or automatically. Automatic initiating devices may respond to smoke, heat, or waterflow, for example.

Alarm Service. Service required following the receipt of an alarm.

Alarm Signal. A signal, indicating an emergency requiring immediate action, such as a signal indicative of fire.

Alarm System. A combination of compatible initiating devices, control panels, and indicating appliances, designed and installed to produce an alarm signal in the event of fire.

Alarm Verification Feature. A feature of automatic fire detection and alarm systems to reduce unwanted alarms wherein smoke detectors report alarm conditions for a minimum period of time, or confirm alarm conditions within a given time period after being reset, in order to be accepted as a valid alarm initiation signal.

Alert Tone. An attention-getting signal to alert occupants of the pending transmission of a voice message.

All-Call Mode. A selector switch on the fire alarm control unit which allows all speaker circuits to be used for an “All-Call Page” transmission.

Analog Initiating Device (Sensor). An initiating device that transmits a signal indicting varying degrees of conditions as contrasted with a conventional initiating device, which can only indicate an on/off condition.

Analog Intelligent Control Panel. An addressable, programmable fire alarm control unit which determines when and whether a device or system is in alarm.

Analog System. A fire alarm system which measures how much of a substance exists at an automatic initiating device contrasted with a conventional system, which can only determine whether the initiating device is on or off (in alarm or not in alarm). Measurements may include smoke density (percent obscuration), temperature, water level, air pressure, etc.

Analog Smoke Detector. A system smoke detector capable of communicating information regarding measured smoke level to a control unit. This type of detector is capable of sending signals to the control unit, which indicate the analog level of smoke within the detector. An analog smoke detector is typically used as part of an addressable system but differs from the Addressable Smoke Detector in that it is capable of communicating the level of smoke as well as its discrete address and its alarm and/or trouble condition.

Annunciator. A unit containing one or more indicator lamps, alphanumeric displays, or other equivalent means in which indication provides status information about a circuit, condition, or location.

ANSI.
American National Standards Institute, 1430 Broadway, New York, NY 10018.

Approved.
Acceptable to the authority having jurisdiction. The National Fire Protection Association does not approve, inspect, or certify any installations, procedures, equipment, or materials; nor does it approve or evaluate testing laboratories. In determining the acceptability of installations, procedures, equipment, or materials, the authority having jurisdiction may base acceptance on compliance with NFPA or other appropriate standards. In the absence of such standards, said authority may require evidence of proper installation, procedure, or use. The authority having jurisdiction of an organization concerned with product evaluations that are in a position to determine compliance with appropriate standards for the current production of listed items.

Assembly Occupancy.
Assembly occupancies include, but are not limited to, all buildings or portions of buildings used for gatherings of 50 or more persons for such purposes as deliberation, worship, entertainment, eating, drinking, amusement, or awaiting transportation. Assembly occupancies also include special amusement buildings regardless of occupant load. Assembly occupancies include armories, libraries, assembly halls, mortuary chapels, auditoriums, motion picture theaters, bowling lanes, museums, clubrooms, passenger stations and terminals of air, surface, underground, and marine public transportation facilities, college and university classrooms, 50 persons and over, conference rooms, places of religious worship, courtrooms, pool rooms, dance halls, recreation piers, drinking establishments, restaurants, exhibition halls, skating rinks, gymnasiums, and theaters.

ASTM.
American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.

Atrium.
A floor opening or series of floor openings connecting two or more stories that is covered at the top of the series of openings and is used for purposes other than an enclosed stairway; elevator hoistway; escalator opening; or utility shaft used for plumbing, electrical, air conditioning, or communication facilities.

Audible Signal.
The sound made by one or more audible notification appliances such as bells, chimes, horns, and speakers, which respond to the operation of an initiating device.

Audio Voice Link (AVL).
Allows the fire alarm control unit to play a single channel of different voice messages from a library of words.

Authority Having Jurisdiction (AHJ).
The organization, office, or individual responsible for approving equipment, an installation, or a procedure. The phrase “authority having jurisdiction” is used in NFPA documents in a broad manner, since jurisdictions and approval agencies vary, as do their responsibilities. Where public safety is primary, the authority having jurisdiction may be a federal, state, local, or other regional department, or individual such as a fire chief; fire marshal, chief of a fire prevention bureau, labor department, or health department; building official; electrical inspector; or others having statutory authority. For insurance purposes, an insurance inspection department, rating bureau, or other insurance company representative may be the authority having jurisdiction, In many circumstances, the property owner or his or her designated agent assumes the role of the authority having jurisdiction; at government installations, the commanding officer or departmental official may be the authority having jurisdiction.
Automatic. Providing a function without the necessity of human intervention.

Automatic Extinguishing System Supervisory Device.
A device that responds to abnormal conditions that could affect the proper operation of an automatic sprinkler system or other fire extinguishing system(s) or suppression system(s) including, but not limited to, control valves; pressure levels; liquid agent levels and temperatures; pump power and running; engine temperature and overspeed; and room temperature.

Automatic Extinguishing or Suppression System Operation Detector.
A device that automatically detects the operation of a fire extinguishing or suppression system by means appropriate to the system employed.

Automatic Fire Detector.
A device designed to detect the presence of a fire signature and to initiate action. For the purpose of this code, automatic fire detectors are classified as follows:

  • Fire-Gas Detector. A device that detects gases produced by a fire.
  • Heat Detector. A fire detector that senses heat produced by burning substances. Heat is the energy produced by combustion that causes substances to rise in temperature.
  • Other Fire Detectors. Devices that detect a phenomenon other than heat, smoke, flame, or gases produced by a flame.
  • Radiant Energy-Sensing Fire Detector. A device that detects radiant energy (such as ultraviolet, visible, or infrared) that is emitted as a product of combustion reaction and obeys the laws of optics.
  • Smoke Detector. A device that detects visible or invisible particles of combustion.

Automatic Fire Alarm System.
A system in which all or some of the circuits are actuated by automatic devices, such as fire detectors, smoke detectors, heat detectors, and flame detectors.

Automatic Float Charger.
Provides secondary (standby) power for temporary operation of the control unit following the loss of primary (main) power. The float charger keeps the secondary (standby) batteries charged during normal operation.

Auxiliary Box.
A fire alarm box that can be operated from one or more remote actuating devices.

Auxiliary Fire Alarm System.
A system connected to a municipal fire alarm system for transmitting an alarm of fire to the public fire service communications center. Fire alarms from an auxiliary fire alarm system are received at the public fire service communications center on the same equipment and by the same methods as alarms transmitted manually from municipal fire alarm boxes located on streets.

  • Local Energy Type. An auxiliary system that employs a locally complete arrangement of parts, initiating devices, relays, power supply, and associated components to automatically trip a municipal transmitter or master box over electrical circuits that are electrically isolated from the municipal system circuits.
  • Parallel Telephone Type. An auxiliary system connected by a municipally controlled individual circuit to the protected property to interconnect the initiating devices at the protected premises and the municipal fire alarm switchboard.
  • Shunt Auxiliary Type. An auxiliary system electrically connected to an integral part of the municipal alarm system extending the municipal circuit into the protected premises to interconnect the initiating devices, which, when operated, open the municipal circuit shunted around the trip coil of the municipal transmitter or mater box, which is thereupon energized to start transmission without any assistance whatsoever form a local source of power.

Auxiliary Trip Relay.
A relay used to operate a municipal master box from an auxiliarized control panel.

Average Ambient Sound Level. The root mean square, A-weighted sound pressure level measured over a 24-hour period.
 
B
Battery. A backup power source usually rechargeable to provide power in case of AC loss.

Bell.
A single stroke or vibrating type audible notification appliance which has a bell tone.

Bell, Single Stroke.
A bell whose gong is struck only once each time operating energy is applied.

Bell, Vibrating.
A bell that rings continuously as long as operating power is applied.

Bell, Motorized.
A bell whose gong is motorized and rings continuously as long as operating power is applied.

BOCA.
Building Officials and Code Administrators, 4051 W Flossmoor Rd, Country Club Hills, IL 60478.

Box (or Station) Fire Alarm (Noncoded).
A manually operated device which, when operated, closes or opens one or more sets of contacts and generally locks the contacts in the operated position until the box is reset.

Box (or Station) Fire Alarm (Coded).
A manually operated device in which the act of pulling a lever causes the transmission of not less than three rounds of coded alarm signals. Similar to the noncoded type, except that instead of a manually operated switch, a mechanism to rotate a code wheel is utilized. Rotation of the code wheel, in turn, causes an electrical circuit to be alternately opened and closed, or closed and opened, thus sounding a coded alarm that identifies the location of the box. The code wheel is cut for the individual code to be transmitted by the device and can operate by clockwork or by an electric motor. Clockwork transmitters can be prewound or can be wound by the pulling of the alarm lever. Usually the box is designed to repeat its code four times and automatically come to rest. Prewound transmitters must sound a trouble signal when they require rewinding. Solid state electronic coding devices are also used in conjunction with the fire alarm control unit to produce coded sounding of the audible signaling appliances.

Box, Breakglass Fire Alarm.
A fire alarm box in which it is necessary to break a special glass or fiber element in order to operate the box. The special element must be replaced once the box is actuated.

Box, Non-breakglass (BNG) Fire Alarm.
A fire alarm box, which is held in its normal state by a spring or other mechanical device. Once the box is actuated, it must be manually reset with a key or special tool.

Box Battery.
The battery supplying power for an individual fire alarm box where radio signals are used for the transmission of box alarms.

Branch Circuit.
The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).

Bridging Point.
The point at which the distribution of signaling line circuits to trunk facilities, leg facilities, or both occur.

Building, Existing.
Any structure erected or officially authorized prior to the effective date of the adoption of this edition of the Code by the agency or jurisdiction. With respect to judging whether a building should be considered existing, the deciding factor is not when the building was designed or when construction started but rather the date plans were approved for construction by the appropriate authority having jurisdiction. It is intended that the initial assessment of the building, when new, should be based on new occupancy requirements for the edition of the Code in effect on the date of plan approval. Subsequent assessments of the building made while that edition of the Code is still in effect should also be based on new occupancy requirements.

Business Occupancy.
Business occupancies are those used for the transaction of business (other than those covered under Mercantile Occupancy), for the keeping of accounts and records, and for similar purposes. Business occupancies include air traffic control towers (ACTCs); courthouses; city halls; dentists”’” offices; college and university instructional buildings, classrooms under 50 persons, and instructional laboratories; doctors’ offices; general offices; outpatient clinics, ambulatory; and town halls.

Bypass.
To temporarily de-activate a portion of the input devices , so as not to trigger the alarm system while armed . This feature is usually used when a sensor is defective , or a window is intentionally left open .
 
C
Cabinet. Fire alarm control unit enclosure.

CABO.
Council of American Building Officials, 5203 Leesburg Pike, Falls Church, VA 22041.

Carrier.
High frequency energy that can be modulated by voice or signaling impulses.

Carrier System.
A means of conveying a number of channels over a single path by modulating each channel on a different carrier frequency and demodulating at the receiving point to restore the signals to their original form.

Cathode Ray Tube (CRT).
An electronic tube used to display data, such as a monitor, that is coated internally with a phosphorescent material. When the electron beam strikes the phosphor, an electron is in turn released thus causing it to glow.

Ceiling.
The upper surface of a space, regardless of height. Areas with a suspended ceiling have two ceilings, one visible from the floor and one above the suspended ceiling.

Ceiling Height.
The height from the continuous floor of a room to the continuous ceiling of a room or space.

Ceiling Surfaces.
Ceiling surfaces referred to in conjunction with the locations of initiating devices are defined as follows:

  • Beam Construction. Ceilings having solid structural or solid nonstructural members projecting down from the ceiling surface more than 4 in. (100 mm) and spaced more than 3 ft (0.9 m) center to center.
  • Girder. A support for beams or joists that runs at right angles to the beams or joists. Where the top of girders are within 4 in. (100 mm) of the ceiling, they are a factor in determining the number of detectors and are to be considered as beams. Where the top of the girder is more than 4 in. (100 mm) from the ceiling, it is not a factor in detector locations.

Central Processing Unit (CPU).
An arrangement of circuitry using computer circuit techniques usually consisting of memory elements, signal processing circuitry, and a means to input and output data at very high speed.

Central Station.
A supervising station that is listed for central station service.

Central Station Fire Alarm System.
A system or group of systems in which the operations of circuits and devices are transmitted automatically to, recorded in, maintained by, and supervised from a listed central station having competent and experienced servers and operators who, upon receipt of a signal, take such action as required by this code. Such service is to be controlled and operated by a person, firm, or corporation whose business is the furnishing, maintaining, or monitoring of supervised fire alarm systems.

Central Station Service.
The use of a system or a group of systems in which the operations of circuits and devices at a protected property are signaled to, recorded in, and supervised from a listed central station having competent and experienced operators who, upon receipt of a signal, take such action as required by NFPA 72, National Fire Alarm ode. Related activities at the protected property such as equipment installation, inspection, testing, maintenance, and runner service are the responsibility of the central station or a listed fire alarm service-local company. Central station service is controlled and operated by a person, firm, or corporation whose business is the furnishing of such contracted services or whose properties are the protected premises.

Certification.
A systematic program using randomly selected follow-up inspections of the certified systems installed under the program that allows the listing organization to verify that a fire alarm system complies with all the requirements of this code. A system installed under such a program is identified by the issuance of a certificate and is designated as a certificated system.

Certification of Personnel.
A formal program of related instruction and testing as provided by a recognized organization or the authority having jurisdiction.

Channel.
A path for voice or signal transmission utilizing modulation of light or alternating current within a frequency band.

Chime.
A single-stroke or vibrating-type audible signal appliance that has a xylophone-type striking bar.

Circuit.
The conductors or radio channel and associated equipment used to perform a definite function in connection with an alarm system.

Circuit Interface.
A circuit component that interfaces initiating devices or control circuits, or both, notification appliances or circuits, or both, system control outputs, and other signaling line circuits to a signaling line circuit.

Circuit Resistance.
The total resistance measured at the termination point of a circuit, excluding any connected components.

Class A Circuit.
Circuits capable of transmitting an alarm signal during a single open or a nonsimultaneous single ground fault on a circuit conductor shall be designated as Class A. It is commonly known as a 4-wire circuit.

Class B Circuit.
Circuits not capable of transmitting an alarm beyond the location of a single open or a nonsimultaneous single ground fault on a circuit conductor shall be designated, as Class B. It is commonly known as a
2-wire circuit with end-of-line resistor.

Cloud Chamber Smoke Detection.
The principle of using an air sample drawn from the protected area into a high humidity chamber combined with a lowering of chamber pressure to create an environment in which the resultant moisture in the air condenses on any smoke particles present, forming a cloud, The cloud density is measured by a photoelectric principle. The density signal is processed and used to convey an alarm condition when it meets preset criteria.

Coded.
An audible or visible signal conveying several discrete bits or units of information. Notification signal examples are numbered strokes of an impact-type appliance and numbered flashes of a visible appliance.

Coded Signal.
A signal pulsed in a prescribed code for each round of transmission. A minimum of three rounds and a minimum of three impulses are required for an alarm signal.

Combination Detector.
A device that either responds to more than one of the fire phenomenon or employs more than one operating principle to sense one of these phenomenon. Typical examples are a combination of a heat detector with a smoke detector or a combination rate-of-rise and fixed-temperature heat detector.

Combination Fire Alarm and Guard’s Tour Box.
A manually operated box for separately transmitting a fire alarm signal and a distinctive guard patrol tour supervisory signal.

Combination System.
A fire alarm system whose components might be used, in whole or in part, in common with a nonfire signaling system, such as a paging system, a security system, a building automatic system, or a process monitoring system.

Combustible.
Capable of undergoing combustion.

Combustion.
A chemical process that involves oxidation sufficient to produce light or heat.

Communications Channel.
A circuit or path connecting a subsidiary station(s) over which signals are carried.

Compatibility Listed.
A specific listing process that applies only to two-wire devices (such as smoke detectors) designed to operate with certain control equipment.

Compatible (Equipment).
Equipment that interfaces mechanically or electrically as manufactured without field modification.

Contiguous Property.
A single-owner or single-user protected premises on a continuous plot of ground, including any buildings thereon, that is not separated by a public thoroughfare, transportation right-of-way, property owned or used by others, or body of water not under the same ownership.

Control-by-Event.
A method of providing a variety of output responses based upon various initiating conditions (events).

Control Panel.
This is the “brains” of the Alarm System , which receive information from all the Input Devices (contact , motion detector glass break detectors etc) process the information and triggers an OUTPUT DEVICE (dialer, siren , strobe light etc.)

Control Unit.
A system component that monitors inputs and controls outputs through various types of circuits.

Conventional Control Panel.
A fire alarm panel that can only monitor on/off signals.

Cross-Zone.
An initiating circuit configuration, which allows an alarm only after two or more devices, is in alarm.

Critical Radiant Flux.
The level of incident radiant heat energy on a floor covering system at the most distant flameout
point as determined by the test procedure of NFPA 253, Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source. The unit of measurement of critical radiant flux is watts per square centimeter (W/sq. cm).
 
D
Damp Location. See Location, Damp.

Data Gathering Panel (DGP).
A remote fire alarm control unit that sends information to a master control unit.

Day-Care Occupancy.
Day-care occupancies include all buildings or portions of buildings in which four or more clients receive care, maintenance, and supervision, by other than their relatives or legal guardians, for less than 24 hours per day. Day-care occupancies include; child day-care occupancies; kindergarten classes that are incidental to a child day-care occupancy; adult day-care occupancies, except where part of a health care occupancy; nursery schools; and day-care homes.

Day/Night Sensitivity.
A method by which intelligent detectors are forced into high or low sensitivity at certain times of the day.

Delay Zones.
Any zone that after has been violated ,waits a predetermined time before triggering an alarm. This type of zone is related to entry doors into the premises.

Delinquency Signal.
A signal indicating the need for action in connection with the supervision of guards or system attendants.

Deluge System.
A system which releases water in the event of a fire.

Derived Channel.
A signaling line circuit that uses the local leg of the public switched network as an active multiplex channel while simultaneously allowing that leg’s use for normal telephone communications.

Detector.
A device suitable for connection to a circuit having a sensor that responds to a physical stimulus such as heat or smoke.

Detector Coverage.
The recommended area that a detector is listed to protect.

Detention and Correction Occupancy.
Detention and correctional occupancies are used to house individuals under varied degrees of restraint or security and are occupied by person who are mostly incapable of self-preservation because of security measures not under the occupants’; control. Detention and correctional occupancies include; adult and juvenile substance abuse centers; adult local detection facilities; adult and juvenile work camps; juvenile community residential centers; adult community; residential centers; juvenile detention facilities; adult correctional institutions; and juvenile training schools.

Digital Alarm Communicator Receiver (DACR).
A system component that accepts and display signals from digital alarm communicator transmitters (DACTs) sent over the public switched telephone network.

Digital Alarm Communicator System (DACS).
A system in which signals are transmitted from a digital alarm communicator transmitter (DACT) located at the protected premises through the public switched telephone network to a digital alarm communicator receiver (DACR).

Digital Alarm Communicator Transmitter (DACT).
A system component at the protected premises to which initiating devices or groups of devices are connected. The DACT seizes the connected telephone line, dials a preselected number to connect to a DACR, and transmits signals indicating a status change of the initiating device.

Digital Alarm Radio Receiver (DARR).
A system component composed of two subcomponents: one that receives and decodes radio signals, and another that annunciates the decoded data. These two subcompononents can be coresident at the central station or separated by means of a data transmission channel.

Digital Alarm Radio System (DARS).
A system in which signals are transmitted from a digital alarm radio transmitter (DART) located at a protected premises through a radio channel to a digital alarm radio receiver (DARR).

Digital Alarm Radio Transmitter (DART).
A system component that is connected to or an integral part of, a DACT that is used to provide an alternate radio transmission channel.

Diode Matrix.
A circuit of diodes that allows the fire alarm control unit to control outputs by inputs using logic, such as Floor Above, Floor Below, and Fire Floor. A diode matrix is typically found in hard-wired panels, which require such features. In microprocessor-based panels, software programming replaces the diode matrix.

Display.
The visual representation of output data as opposed to printed copy.

Direct Line.
Also know as Dedicated Line or Direct Line. Special supervised phone line between Alarm System and Monitor Station , that if is cut or tampered with the Monitoring Station will be alerted and take appropriate action. Direct Line is used for higher security level required for computer store, financial institution , jewelry and fur store , gun shop etc witch require a ULC Certificate.

Door Holder.
An electromagnetic device used to hold a door open while energized. In the event of a fire, the door holder is de-energized and the door is allowed to close.

Double Doorway.
A single opening that has no intervening wall space or door trim separating the two doors.

Draft Stop.
A continuous membrane used to subdivide a concealed space to restrict the passage of smoke, heat, and flames.

Drift Compensation.
An algorithm which permits a smoke detector to maintain a constant sensitivity setting by adjusting for environmental contaminants and other factors.

Dry Location.
See Location, Dry.

Dual Control.
The use of two primary trunk facilities over separate routes or different methods to control one communications channel.

Dual Detector.
A Motion Sensor which utilizes more than one sensing technology to initiate an alarm condition. A usual combination is PIR with Microwave or UltraSonic detector. These devices are more stable and less likely to create a False Alarm.

Duct Detector.
Initiating devices designed to sample air passing through an HVAC duct and allows for early detection of a developing fire.

Dwelling Unit.
A single unit, providing complete, independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking, and sanitation.
 
E
Educational Occupancy. Educational occupancies include all buildings or portions of buildings used for educational purposes through the twelfth grade by six or more persons for four or more hours per day or more than 12 hours per week. Educational occupancies include academies, nursery schools, kindergartens, and schools.

EIA-232 and EIA-485.
Communications interface standards as described by the Electronics Industries Association, a US standards making organization.

Ember.
A particle of solid material that emits radiant energy due either to its temperature or the process of combustion on its surface. (See Spark). Class A and Class D combustibles burn as embers under conditions where the flame typically associated with fire does not necessarily exist. This glowing combustion yields radiant emissions in parts of the radiant energy spectrum that are radically different from those parts affected by flaming combustion. Specialized detectors, specifically designed to detect those emissions, should be used in applications where this type of combustion is expected. In general, flame detectors are not intended for the detection of embers.

Emergency Voice/Alarm Communications.
Dedicated manual or automatic facilities for originating and distributing voice instructions, as well as alert and evacuation signals pertaining to a fire emergency, to the occupants of a building.

End-of-Line Device.
A device used to terminate a supervised circuit. Typically a resistor or diode is installed in series at the end of a two-wire circuit to maintain supervision.

End-of-Line Relay.
A relay used to supervise power, for example, supplied to a 4-wire smoke detector or power to an addressable device. The relay is installed within or adjacent to the last powered device on the circuit.

Erasable Programmable Read Only Memory (EPROM).
A nonvolatile semiconductor memory component whose contents may be erased, usually through exposure to ultraviolet light. EPROM’s are used to store digital data.

Evacuation.
The withdrawal of occupants from a building. Evacuation does not include relocation of occupants within a building.

Evacuation Signal.
A distinctive signal intended to be recognized by the occupants as requiring evacuation of the building.

Existing.
That which is already in existence on the date when the current edition of the Code goes into effect. See Building, Existing.

Exit.
That portion of a means of egress that is separated from all other spaces of the building or structure by construction or equipment as required in NFPA 101 5-1.3.2.1 to provide a protected way of travel to the exit discharge. Exits include exterior exit doors, exit passageways, horizontal exits, separated exit stairs, and separated exit ramps.

Exit Access.
That portion of a means of egress that leads to an exit.

Exit Plan.
A plan for the emergency evacuation of the premises.

External Interface.
An EIA-485 bi-directional serial port used to upload and download data.
 
F
Family Living Unit. One or more rooms in a single-family detached dwelling, single-family attached dwelling, multifamily dwelling, or mobile home for the use of one or more persons as a housekeeping unit with space for eating, living, and sleeping and permanent provisions for cooking and sanitation. This definition covers living areas only and not common usage areas in multifamily dwellings such as corridors, lobbies, or basements.

False Alarm.
A situation were an alarm signal is triggered without any intrusion attempt . Some causes of this are user error (accounts for over 80%) , telephone line trouble and equipment malfunction.

Fault.
An open, ground, or short condition on any lines(s) extending from a control unit, which could prevent normal operation.

Field of View.
The solid cone extending out from the detector within which the effective sensitivity of the detector is at least 50 percent of its on-axis, listed, or approved sensitivity.

Fire.
A chemical reaction that occurs when a combustible material is exposed to oxygen during which rapid oxidation results in the release of heat, light, flame, and/or smoke.

Fire Alarm Control Unit (Panel).
A system component that receives inputs from automatic and manual fire alarm devices and might supply power to detection devices and a transponder(s) or an off-premises transmitter(s). The control unit might also provide transfer of power to the notification appliances and transfer of condition to relays or devices connected to the control unit. The fire alarm control unit can be a local fire alarm control unit or master control unit.

Fire Alarm/Evacuation Signal Tone Generator.
A device that, upon command, produces a fire alarm/evacuation tone.

Fire Alarm Signal.
A signal initiated by a fire alarm-initiating device such as a manual fire alarm box, automatic fire detector, waterflow switch, or other device whose activation is indicative of the presence of a fire or fire signature.

Fire Alarm System.
A system or portion of a combination system consisting of components and circuits arranged to monitor and annunciate the status of fire alarm or supervisory signal-initiating devices and to initiate the appropriate response to those signals.

Fire Barrier.
A continuous membrane, either vertical or horizontal, such as a wall or floor assembly that is designed and constructed with a specified fire resistance rating to limit the spread of fire and that also will restrict the movement of smoke. Such barriers might have protected openings.

Fire Barrier Wall.
A wall, other than a fire wall, having a fire resistance rating.

Fire Command Center.
The principal attended or unattended location where the status of the detection, alarm communications, and control systems is displayed and from which the system(s) can be manually controlled.

Fire Compartment.
A space within a building, that is enclosed by fire barriers on all sides, including the tip and bottom. In the provisions of fire compartments utilizing the outside walls of a building, it is not intended that the outside wall be specifically fire resistance-rated unless required by other standards. Likewise it is not intended for outside windows or doors to be protected unless specifically required for exposure protection by another section of this Code or by other standards.

Fire Protection Rating.
The designation indicating the duration of the fire test exposure to which a fire door assembly or fire window assembly was exposed and successfully met all the acceptance criteria as determined in accordance with NFPA 252, Standard Methods of Fire Tests of Door Assemblies, or NFPA 257, Standard on Fire Test for Window and Glass Block Assemblies, respectively.

Fire Rating.
The classifications indicating in time (hours) the ability of a structure or component to withstand fire conditions.

Fire Resistance Rating.
The time, in minutes or hours, that materials or assemblies have withstood a fire exposure as established in accordance with the test procedures of NFPA 251, Standard Methods of Tests of Fire Endurance of Building Construction and Materials.

Fire-Gas Detector.
A device that detects the gases produced by a fire.

Fire Safety Function Control Device.
The fire alarm system component that directly interfaces with the control system that controls the fire safety function.

Fire Safety Functions.
Building and fire control functions that are intended to increase the level of life safety for occupants or to control the spread of the harmful effects of fire.

Fire Warden.
A building staff member or a tenant trained to perform assigned duties in the event of a fire emergency.

Fixed Temperature Detector.
A device that responds when its operating element becomes heated to a predetermined level. The difference between the operating temperature of a fixed temperature device and the surrounding air temperature is proportional to the rate at which the temperature is rising and is commonly referred to as “thermal lag.” The air temperature is always higher than the operating temperature of the device. Typical examples of fixed temperature-sensing elements follow.

  • Bimetallic. A sensing element comprised of two metals having different coefficients of thermal expansion arranged so that the effect is deflection in one direction when heated and in the opposite direction when cooled.
  • Electrical Conductivity. A line-type or spot-type sensing element whose resistance varies as a function of temperature.

Fusible Alloy.
A sensing element of a special composition (eutectic) metal that melts rapidly at the rated temperature.
  • Heat-Sensitive Cable. A line-type device in which a sensing element comprises, in one type, two current-carrying wires separated by heat-sensitive insulation that softens at the rated temperature, thus allowing the wires to make electrical contact. In another type, a single wire is centered in a metallic tube, and the intervening space is filled with a substance that, at a critical temperature, becomes conductive, thus establishing electrical contact between the tube and the wire.
  • Liquid Expansion. A sensing element comprising a liquid capable of marked expansion in volume in response to temperature increase.

Flame.
A body or stream of gaseous material involved in the combustion process and emitting radiant energy at specific wavelength bands determined by the combustion chemistry of the fuel. In most cases, some portion of the emitted radiant energy is visible to the human eye.

Flame Detector.
A radiant energy-sensing fire detector that detects the radiant energy emitted by a flame. Flame detectors are categorized as ultraviolet, single wavelength infrared, ultraviolet infrared, or multiple wavelength infrared.

Flame Detector Sensitivity.
The distance along the optical axis of the detector at which the detector can detect a fire of specified sized and fuel within a given time frame.

Flame Spread.
The propagation of flame over a surface.

FM.
Factory Mutual Engineering Corporation, 1151 Boston Providence Turnpike, Norwood, MA 02062.

Four-Wire Smoke Detector.
A smoke detector which is connected to the fire alarm control unit by two, two-wire circuits. One circuit is the initiating device circuit while the other circuit provides supervised power to the detector, typically 12 VDC or 24 VDC.

Frequency Division Multiplexing.
A signaling method characterized by the simultaneous transmission of more than one signal in a communication channel. Signals from one or multiple terminal locations are distinguished from one another by virtue of each signal being assigned to a separate frequency or combination of frequencies.
 
G
General Alarm. A term usually applied to the simultaneous operation of all audible alarm signals on a system to indicate the need to evacuate a building.

Ground Fault.
A condition in which the resistance between a conductor and ground reaches an unacceptably low level.

Ground Fault Detector.
Detects the presence of a ground condition on system wiring.

Guard Signal.
A supervisory signal monitoring the performance of guard patrols.

Guard’s Tour Reporting Station.
A device that is manually or automatically initiated to indicate the route being followed and the timing of a guard’s tour.

Guard’s Tour Supervision.
Devices that are manually or automatically initiated to indicate the route being followed and the timing of a guard’s tour.
 
H
Hazardous Area. Those areas of structures or buildings posing a degree of hazard greater than that normal to the general occupancy of a building or structure, such as those areas used for the storage or use of combustibles or flammables; toxic, noxious, or corrosive materials; or heat-producing appliance.

Health Care Occupancy.
Health care occupancies are those used for purposes such as medical or other treatment or care of persons suffering from physical or mental illness, disease, or infirmity; and for the care of infants, convalescents, or infirm aged persons. Health care occupancies provide sleeping facilities for four or more occupants and are occupied by persons who are mostly incapable of self-preservation because of age, physical or mental disability, or because of security measures not under the occupants’ control. Health care occupancies include hospitals, limited care facilities, and nursing homes. Health care occupancies also include ambulatory health care centers.

Heat Alarm.
A single or multiple station alarm responsive to heat.

Heat Detector.
A fire detector that senses heat produced by burning substances. Heat is the energy produced by combustion that causes substances to rise in temperature.

High-Rise Building.
A building more than 75 ft (23 m) in height. Building height shall be measured from the lowest level of fire department vehicle access to the floor of the highest occupiable story. It is the intent of this definition that in determining the level from which the highest occupiable floor is to be measured, the enforcing agency should exercise reasonable judgment, including consideration of overall accessibility to the building by fire department personnel and vehicular equipment. Where a building is situated on a sloping terrain and there is building access on more than one level, the enforcing agency may select the level that provides the most logical and adequate fire department access.

Hoistway.
Any shaftway, hatchway, well hole, or other vertical opening or space in which an elevator or dumbwaiter is designed to operate.

Horn.
An audible notification appliance in which electrical energy is used to produce a sound by driving a device which imparts motion to a flexible component that vibrates at a nominal frequency.

Horn/Strobe.
A combination audible and visible notification appliance, which operates as a horn and a strobe light, simultaneously. The horn produces a sound at a nominal frequency and the strobe light flashes at a predetermined rate.

Household.
The family living unit in single-family detached dwellings, single-family attached dwellings, multi-family buildings, and mobile homes.

Household Fire Alarm System.
A system of devices that produces an alarm signal in the household for the purpose of notifying the occupants of the presence of a fire so that they will evacuate the premises.

Hunt Group.
A group of associated telephone lines within which an incoming call is automatically routed to an idle (not busy) telephone line for completion.
 
I-J-K
ICBO. International Conference of Building Officials, 5360 Workman Mill Road, Whittier, CA 90601.

Industrial Occupancy.
Industrial occupancies include factories making products of all kinds and properties devoted to operations such as processing, assembling, mixing, packaging, finishing or decorating, and repairing. Industrial occupancies include dry cleaning plants; laundries; factories of all kinds; power plants; food processing plants; pumping stations; gas plants; refineries; hangars (for servicing/maintenance); sawmills; and telephone exchanges.

Initiating Device.
A system component that originates transmission of a change of state condition, such as in a smoke detector, manual fire alarm box, or supervisory switch.

Initiating Device Circuit (IDC).
A circuit to which automatic or manual initiating devices are connected where the signal received does not identify the individual device operated.

Intelligent System.
A system using analog devices communicating with a control unit that individually monitors the value or status reported by the analog sensors and makes the normal, alarm, or trouble decisions.

Integrated System.
A computer-based control system listed for use as a fire alarm system, in which certain components are common to nonfire monitoring and control functions.

Intermediate Fire Alarm or Fire Supervisory Control Unit.
A control unit used to provide area fire alarm or area fire supervisory service that, where connected to the proprietary fire alarm system, becomes a part of that system.

Ionization Smoke Detection.
The principle of using a small amount of radioactive material to ionize the air between two differentially charged electrodes to sense the presence of smoke particles. Smoke particles entering the ionization volume decrease the conductance of the air by reducing ion mobility. The reduced conductance signal is processed and used to convey an alarm condition when it meets preset criteria. Ionization smoke detection is more responsive to invisible particles (smaller than 1 micron in size) produced by most flaming fires. It is somewhat less responsive to the larger particles typical of most smoldering fire. Smoke detectors utilizing the ionization principle are usually of the spot type.

Keypad.
A keyboard type device used for entering a numeric code to ARM or DISARM the ALARM SYSTEM. On keypad there are usually displayed status of zones , c. panel and power.
 
L
Labeled. Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation that maintains periodic inspection of production of labeled equipment or materials and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.

Lamp Test.
Activation of all control unit lights for test purposes.

Last Event Recall.
The ability to review the last event in a control unit history.

Leg Facility.
The portion of a communications channel that connects not more than one protected premises to a primary or secondary trunk facility. The leg facility includes the portion of the signal transmission circuit from its point of connection with a trunk facility to the point where it is terminated within the protected premises at one or more
transponders.

Level Ceilings.
Ceilings that are actually level or have a slope of 1 1/2 in./ft (41.7 mm/m) or less.

Lexan®.
Single strength glass (which is easily replaced when broken) manufactured by GE plastics used for windows and covers on manual pull stations and on fire alarm cabinet doors.

Light Emitting Diode (LED).
A diode that emits visible light when current is applied. LED’s are used as single element visible indicators or as multiple-segment displays.

Light Scattering.
The action of light reflected and/or refracted off particles of combustion for detection in a photoelectric smoke detector, also known as the “Tyndall Effect”.

Limited-Combustible.
As applied to a building construction material, other than interior finish, means a material not
complying with the definition of noncombustible material that, in the form in which it is used has a potential heat value not exceeding 3500 Btu/lb. (8.14 X 106 J/kg) and complies with one of the following paragraphs, (a),(b) or (c).

  • (a) Materials having a structural base of noncombustible material with a surface not exceeding a thickness of 1/8 in. (0.3 cm) that has a flame spread rating not greater than 50.
  • (b) Materials, in the form and thickness used, other than as described in (a), having neither a flame spread rating greater than 25 nor evidence of continued progressive combustion, and of such composition that surfaces that would be exposed by cutting through the material on any plane would have neither a flame spread rating greater than 25 nor evidence of continued progressive combustion.
  • (c) Materials subject to increase combustibility or flame spread rating beyond the limits herein established through the effects of age, moisture, or other atmospheric condition shall be considered combustible. See NFPA 259, Standard Test Method for Potential Heat of Building Materials, and NFPA 220, Standard on Types of Building Construction.

Line-Type Detector.
A device in which detection is continuous along a path. Typical examples are rate-of-rise pneumatic tubing detectors, projected beam smoke detectors, and heat-sensitive cable.

Liquid Crystal Display (LCD).
An arrangement of individual segments used to display information. Each segment becomes transparent or opaque as electric current is applied or removed from each segment.

Listed.
Equipment, materials, or services included in a list published by an organization acceptable to the authority having jurisdiction and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services and whose listing states either that the equipment, material, or service meets identified standards or has been tested and found suitable for a specified purpose. The means for identifying listed equipment may vary for each organization concerned with product evaluation, some of which do not recognize equipment as listed unless it is also labels. The authority having jurisdiction should utilize the system employed by the listing organization to identify a listed product.

Living Area.
Any normally occupiable space in a residential occupancy, other than sleeping rooms or rooms that are intended for combination sleeping/living, bathrooms, toilet compartments, kitchens, closets, halls, storage or utility spaces, and similar areas.

Loading Capacity.
The maximum number of discrete elements of fire alarm systems permitted to be used in a particular configuration.

Local Control Unit (Panel).
A control unit that serves the protected premises or a portion of the protected premises and indicates the alarm via notification appliances inside the protected premises.

Local Energy Master Box.
A municipal master box that uses electrical energy from the protected premises to energize its electromagnetic tripping mechanism. See Shunt Master Box.

Local Fire Alarm System.
A local system sounding an alarm at the protected premises as a result of the manual operation of a fire alarm box or the operation of protection equipment or systems, such as water flowing in a sprinkler system, the discharge of carbon dioxide, the detection of smoke, or the detection of heat.

Local Supervisory System.
A local system arranged to supervise the performance of guard patrols or the operative condition of an automatic sprinkler system or other system used for the protection of life and property against fire.

Location, Damp.
Locations protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture. Examples of such locations include partially protected locations under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderate degrees of moisture, such as some basements, some barns, and some cold-storage warehouses.

Location, Dry.
A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.

Location, Wet.
Installations under ground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.

Loss of Power.
The reduction of available voltage at the load below the point at which equipment can function as designed.

Low Power Radio Transmitter.
Any device that communicates with associated control/receiving equipment by low power radio signals.
 
M
Maintenance. Repair service, including periodic inspections and tests, required to keep the fire alarm system and its component parts in an operative condition at all times, together with replacement of the system or its components when they become undependable or inoperable for any reason.

Manual Fire Alarm Box.
A manually operated device used to initiate an alarm signal.

Master Box.
A municipal fire alarm box that can also be operated by remote means.

Master Clock.
Time indicating appliance, which is designed to provide, synchronized time reporting for secondary clocks.

Master Control Unit (Panel).
A control unit that serves the protected premises or portion of the protected premises as a local control unit and accepts inputs from other fire alarm control units.

Mercantile Occupancy.
Mercantile occupancies include stores, markets, and other rooms, buildings, or structures for the display and sale of merchandise. Mercantile occupancies include auction rooms, shopping centers, department
stores, supermarkets, and drugstores.

Microprocessor.
A complex circuit element that is usually the main control for a central processing unit. A single such component may house the entire central processor unit in a fire alarm control unit.

Model Codes.
BOCA National Code, ICBO Uniform Building Code, SBCCI Standard Building Code.

Monitored Alarm.
Alarm system which sends information to a CENTRAL STATION or MONITORING STATION.

Motion Sensors.
Commonly referred as PIR (passive Infra Red) works on principle of sensing infrared energy (heat) from the intruder’s body in motion trough a protected area. It will not detect intruders trough walls , glass or others solid objects.

MPS (Main Power Supply).
The main power supply of a control unit provides all of the necessary power to operate the control unit plus the power required to operate automatic initiating devices and notification appliances and annunciators.

Multiple Station Alarm.
A single station alarm capable of being interconnected to one or more additional alarms so that the actuation of one causes the appropriate alarm signal to operate in all interconnected alarms.

Multiple Station Alarm Device.
Two or more single station alarm devices that can be interconnected so that actuation of one causes all integral or separate audible alarms to operate. It also can consist of one single station alarm device having connections to other detectors or to a manual fire alarm box.

Multiplexed Initiating Device Loop.
A circuit that connects the transponder or digital alarm communicator transmitter (DACT) to a number of initiating device interfaces.

Multiplexing.
A signaling method characterized by simultaneous or sequential transmission, or both, and reception of multiple signals on a signaling line circuit, a transmission channel, or a communications channel, including means for positively identifying each signal.

Municipal Communications Center.
The building or portion of a building used to house the central operating part of the fire alarm system; usually the place where the necessary testing, switching, receiving, retransmitting, and power supply devices are located.

Municipal Fire Alarm Box (Street Box).
An enclosure housing a manually operated transmitter used to send an alarm to the public fire service communications center.

Municipal Fire Alarm System.
A system of alarm-initiating devices, receiving equipment, and connecting circuits (other than a public telephone network) used to transmit alarms from street locations to the public fire service communications center.

Municipal Transmitter.
A transmitter that can only be tripped remotely that is used to send an alarm to the public fire service communications center.
 
N
Network System. A system in which individual control units form a single network and are typically monitored via a CRT.

NFPA.
National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269.

Noise.
An electronics term that covers all types of unwanted electrical signals. Noise signals originate from such sources as fluorescent lamps; walkie-talkies; amateur and CB radios; electronic machines being switched on and off; power surges; and others. Electronic equipment must be able to tolerate increasing amounts of electrical interference. The quality of electronic equipment is directly proportional with its ability to reject and otherwise ignore noise.

Noncoded.
An audible or visible signal conveying one discrete bit of information.

Noncombustible.
A material that, in the form in which it is used and under the conditions anticipated will not aid combustion or add appreciable heat to an ambient fire. Materials, where tested in accordance with ASTM E136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 7500C, and conforming to the criteria contained in Section 7 of the referenced standard shall be considered as noncombustible.

Noncontiguous Property.
An owner- or user-protected premises where two or more protected premises, controlled by the same owner or user, are separated by a public thoroughfare, body of water, transportation right-of-way, or property owned by others.

Nonrestorable Initiating Device.
A device, which contains a sensing element that, is designed to be destroyed in the process of operation.

Notification Appliance.
A fire alarm system component such as a bell, horn, speaker, light, or text display that provides audible, tactile, or visible outputs or any combination thereof.

  • Audible Notification Appliance. A notification appliance that alerts by the sense of hearing.
  • Audible Textual Notification Appliance. A notification appliance that conveys a stream of audible information. An example of an audible textual appliance is a speaker that reproduces a voice message.
  • Olfactory Notification Appliance. A notification appliance that alerts by the sense of smell.
  • Tactile Notification Appliance. A notification appliance that alerts by the sense of touch or vibration.
  • Visible Notification Appliance. A notification appliance that alerts by the sense of sight.
  • Visible Textual Notification Appliance. A notification appliance that conveys a stream of visible information. An example of a visible textural appliance is a monitor that displays an alphanumeric or pictorial message.

Notification Appliance Circuit (NAC).
A circuit or path directly connected to a notification appliance(s).

Notification Zone.
An area covered by notification appliances that are activated simultaneously.

Nuisance Alarm.
Any alarm caused by mechanical failure, malfunction, improper installation, or lack of proper maintenance, or any alarm activated by a cause that cannot be determined.
 
O
Obscuration. A reduction in the atmospheric transparency caused by smoke, usually expressed as percent per foot.

Occupancy.
The purpose for which a building or portion thereof is used or intended to be used.

Occupant Load.
The total number of persons that might occupy a building or portion thereof at any one time.

Occupiable Story.
A story occupied by people on a regular basis. Stories used exclusively for mechanical equipment rooms, elevator penthouses, and similar spaces are not occupiable stories.

Off-Hook.
To make connection with the public switched telephone network in preparing to dial a telephone number.

On-Hook.
To disconnect from the public switched telephone network.

Openings & Closings.
Service provided for Monitored Alarm . Each time the alarm system is armed or disarmed special codes are send to the monitoring station which record the time and by whom the system was armed or disarmed. If system is not armed at regular closing time the client is notified. If the system is disarmed at an irregular time ( i.e. 02:00 AM ) the client and/or police is notified.Open=Disarm system ; Close=Arm system .

Open Area Detection (Protection).
Protection of an area such as a room or space with detectors to provide early warning of fire.

Output Circuits.
Speakers, telephone, horn, strobe, bell, signal, etc.

Operating Mode, Private.
Protection of an area such as a room or space with detectors to provide early warning of fire.

Operating Mode, Public.
Audible or visible signaling only to those persons directly concerned with the implementation and direction of emergency action initiating and procedure in the area protected by the fire alarm system.

Operating System Software.
The basic operating system software that is alterable only by the equipment manufacturer or its authorized representative. This software is sometimes referred to as “firmware,” “BIOS,” or “executive program.”

Other Space Used for Environmental Air.
The space over a hung ceiling used for environmental air-handling purposes is an example of the type of other space.

Ownership.
Any property or building or its contents under legal control by the occupant, by contract, or by holding of a title or deed.

Oxidation.
The act or process of oxidizing.

Oxidize.
To combine with oxygen. To change a compound by increasing the proportion of the electronegative part or change and element or ion from a lower to a higher positive valence. To remove one or more electrons from and atom, ion or molecule.
 
P-Q
Paging System. A system intended to page one or more persons by such means as voice over loudspeaker, coded audible signals, or lamp annunciators.

Parallel Telephone System.
A telephone system in which an individually wired circuit is used for each fire alarm box.

Parallel Telephone Auxiliary Alarm System.
See Auxiliary Fire Alarm System.

Particles of Combustion.
Substances resulting from the chemical process of fire. Such particles include ash wish remains at the site of the fire and volatile products, which may evaporate, agglomerate, or condense.

Path (Pathways).
Any conductor, optic fiber, radio carrier, or other means for transmitting fire alarm system information between two or more locations.

Permanent Visual Record (Recording).
An immediately readable, not easily alterable, print, slash, or punch record of all occurrence of status changes.

Phone line Seizure.
When the alarm is activated , this device automatically cuts off the phone service on the alarm line and use it for transmission of the alarm signal , releasing the line when the message is completed .

Photoelectric Light Obscuration Smoke Detection.
The principle of utilizing a light source and a photosensitive sensor onto which the principal portion of the source emissions is focused. When smoke particles enter the light path, some of the light is scattered and some is absorbed, thereby reducing the light reaching the receiving sensor. The light reduction signal is processed and used to convey an alarm condition when it meets preset criteria. The response of photoelectric light obscuration smoke detectors is usually not affected by the color of smoke. Smoke detectors utilizing the light obscuration principle are usually of the line type. These detectors are commonly refereed to as “projected beam smoke detectors.”

Photoelectric Light-Scattering Smoke Detection.
The principle of utilizing a light source and a photosensitive sensor arranged in a manner so that the rays from the light source do not normally fall onto the photosensitive sensor. When smoke particles enter the light path, some of the light is scattered by reflection and refraction onto the sensor. The light signal is processed and used to convey an alarm condition when it meets preset criteria. Photoelectric light-scattering smoke detection is more responsive to visible particles (larger than 1 micron in size) produced by most smoldering fires. It is somewhat less responsive to the smaller particles typical of most flaming fires.

Plant.
One or more buildings under the same ownership or control on a single property.

Plenum.
An air compartment or chamber to which one or more ducts are connected and that forms part of an air distribution system.

NOTE: The definition of plenum is not intended to apply to the space above a suspended ceiling that is used for environmental air referred to in NFPA 70-2002 300.22(C).

Positive Alarm Sequence.
An automatic sequence that results in an alarm signal even when manually delayed for investigation, unless the system is reset.

Positive Non-Interfering (PNI) System.
A system in which the alarm initiating devices are electrically arranged such that if one device is operated to transmit an alarm, no other devices connected to the same circuit is allowed to interfere with the transmission of a complete and unmodified round of alarm signals.

Positive Non-Interfering and Successive System.
A system which prevents subsequently operated initiating devices from interfering with the transmission of an alarm from an operated device and which permits any device to transmit, in turn, its assigned number of rounds of coded signals once the previously actuated device completes its transmission of coded signals.

Power Limited Circuit.
A circuit that limits power to the load inherently or by overcurrent protection.

Power Supply.
A source of electrical operating power including the circuits and terminations connecting it to the dependent system components.

Presignal System.
A feature that allows initial fire alarm signals to sound only in department offices, control rooms, fire brigade stations, or other constantly attended central locations and for which human action is subsequently required to activate a general alarm, or a feature that allows the control equipment to delay the general alarm by more than 1 minute after the start of the alarm processing.

Primary Battery (Dry Cell).
A nonrechargeable battery requiring periodic replacement.

Primary Trunk Facility.
That part of a transmission channel connecting all leg facilities to a supervising or subsidiary station.

Prime Contractor.
The one company contractually responsible for providing central station services to a subscriber as required by this code. This can be either a listed central station or a listed fire alarm service-local company.

Private Radio Signaling.
A radio system under control of the proprietary supervising station.

Projected Beam-Type Detector.
A type of photoelectric light obscuration smoke detector wherein the beam spans the protected area.

Proprietary Supervising Station.
A location to which alarm or supervisory signaling devices on proprietary fire alarm systems are connected and where personnel are in attendance at all times to supervise operation and investigate signals.

Proprietary Supervising Station Fire Alarm System.
An installation of fire alarm systems that serves contiguous and noncontiguous properties, under one ownership, from a proprietary supervising station located at the protected property, at which trained, competent personnel are in constant attendance. This includes the proprietary supervising station; power supplies; signal-initiating devices; initiating device circuits; signal notification appliances; equipment for the automatic, permanent visual recording of signals; and equipment for initiating the operation of emergency building control services.

Protected Premises.
The physical location protected by a fire alarm system.

Protected Premises (Local) Control Unit (Panel).
A control unit that serves the protected premises or a portion of the protected premises and indicated the alarm via notification appliances inside the protected premises.

Protected Premises (Local) Fire Alarm System.
A protected premises system that sounds an alarm at the protected premises as the result of the manual operation of a fire alarm box or the operation of protection equipment or system, such as water flowing in a sprinkler system, the discharge of carbon dioxide, the detection of smoke, or the detection of heat.

Public Fire Service Communications Center.
The building or portion of the building used to house the central operating part of the fire alarm system; usually the place where the necessary testing, switching, receiving, transmitting, and power supply devices are located.

Public Switched Telephone Network.
An assembly of communications facilities and central office equipment operated by authorized common carriers that provides the general public with the ability to establish communications channels via discrete dialing codes.
 
R
Radiant Energy Sensing Fire Detector. See Automatic Fire Detector.

Radio Alarm Central Station Receiver (RARSR).
A system component that receives radio signals. This component resides at a repeater station that is located at a remote receiving location.

Radio Alarm Supervising Station Receiver (RASSR).
A system component that receives data and annunciates that data at the supervising station.

Radio Alarm System (RAS).
A system in which signals are transmitted from a radio alarm transmitter (RAT) located at a protected premises through a radio channel to two or more radio alarm repeater station receivers (RARRSR) and are annunciated by a radio alarm supervising station receiver (RASSR) located at the central station.

Radio Alarm Transmitter (RAT).
A system component at the protected premises to which initiating devices or groups of devices are connected. The RAT transmits signals indicating a status change of the initiating devices.

Radio Channel.
A band of frequencies of a width sufficient to allow its use for radio communications. The width of the channel depends on the type of transmissions and the tolerance for the frequency of emission. Channels normally are allocated for radio transmission in a specified type for service by a specified transmitter.

Rate Compensation Detector.
A device that responds when the temperature of the air surrounding the device reaches a predetermined level, regardless of the rate of temperature rise. A typical example is a spot-type detector with a tubular casing of a metal that tends to expand lengthwise as it is heated and an associated contact mechanism that closes at a certain point in the elongation. A second metallic element inside the tube exerts an opposing force on the contacts, tending to hold them open. The forces are balanced in such a way that, on a slow rate-of-temperature rise, there is more time for heat to penetrate to the inner element, which inhibits contact closure until the total device has been heated to its rated temperature level. However, on a fast rate-of-temperature rise, there is not as much time for heat to penetrate to the inner element, which exerts less of an inhibiting effect so that contact closure is achieved when the total device has been heated to a lower temperature. This, in effect, compensates for thermal lag.

Rate-of-Rise Detector.
A device that responds when the temperature rises at a rate exceeding a predetermined value. Typical examples of rate-of-rise detectors follow Pneumatic Rate-of Rise Tubing. A line-type detector comprising small-diameter tubing, usually copper, that is installed on the ceiling or high on the walls throughout the protected area. The tubing is terminated in a detector unit containing diaphragms and associated contacts set to actuate at a predetermined pressure. The system is sealed except for calibrated vents that compensate for normal changes in temperature.

  • Spot-Type Pneumatic Rate-of-Rise Detector.
A device consisting of an air chamber, a diaphragm, contacts, and a compensating vent in a single enclosure. The principle of operation is the same as that described for pneumatic rate-of-rise tubing.

  • Thermoelectric Effect Detector.
A device in which a sensing element comprises a thermocouple or thermopile unit that produces an increase in electric potential in response to an increase in temperature. This potential is monitored by associated control equipment, and an alarm is initiated when the potential increases at an abnormal rate.


  • Electrical Conductivity-Type Rate-of-Rise Detector.
A line-type or spot-type sensing element whose resistance changes due to a change in temperature. The rate of change of resistance is monitored by associated control equipment, and an alarm is initiated when the rate of temperature increase exceeds a preset value.

Record Drawings. Drawings (as-built) that document the location of all devices, appliances, wiring sequences, wiring methods, and connections of the components of the fire alarm system as installed.

Record of Completion.
A document that acknowledges the features of installation, operation (performance), service, and equipment with representation by the property owner, system installer, system supplier, service organization, and the authority having jurisdiction.

Rectifier.
An electrical device without moving parts that changes alternating current to direct current.

Relocation.
The movement of occupants from a fire zone to a safe area within the same building.

Remote Supervising Station Fire Alarm System.
A system installed in accordance with this code to transmit alarm, supervisory, and trouble signals from one or more protected premises to a remote location at which appropriate action is taken.

Repeater Facility.
Equipment needed to relay signals between supervisory stations, subsidiary stations, and protected premises.

Repeater Station.
The location of the equipment needed for a repeater facility.

Reset.
A control function that attempts to return a system or device to its normal, nonalarm state.

Residential Occupancy.
Residential occupancies are those occupancies in which sleeping accommodations are provided for normal residential purposes and include all buildings designed to provide sleeping accommodations except for those occupancies classified under health care or detention and correctional occupancies. Residential occupancies include hotels, motels, and dormitories; apartment buildings; lodging or rooming houses; one- and two-family dwellings; and board and care facilities.

Restorable Initiating Device.
A device in which a sensing element is not ordinarily destroyed in the process of operation. Restoration can be manual or automatic.

Retard (Adjustable) Waterflow Switches.
An adjustable time delay mechanism in a waterflow switch located between the paddle-operated stem and the initiating contacts. This type of switch is designed to prevent brief water flow surges due to water hammer and/or pressure variations from causing an unwanted alarm signal.

Reverse Polarity Interface.
A connection from a control unit to a supervising station which operates using polarity reversal to signal an alarm, supervisory, or trouble signals.

Ring-Back Circuit.
A circuit which function much like a two-way switch. When a trouble condition occurs, a trouble buzzer and light is energized. When an acknowledge button is depressed, the trouble buzzer and light are reset. When the trouble condition is corrected, the buzzer and light once again are energized indicating an off-normal condition. Once the acknowledge button is released, the circuit returns to normal.

Runner.
A person other than the required number of operators on duty at central, supervising, or runner stations (or otherwise in contact with these stations) available for prompt dispatching, when necessary, to the protected premises.

Runner Service.
The service provided by a runner at the protected premises, including resetting and silencing of all equipment transmitting fire alarm or supervisory signals to an off-premises location.
 
S
Satellite Station. A normally unattended remote location. Interconnection of signal-receiving equipment or communication channels from protected premises, which include circuits connecting central supervising station(s) are accomplished here.

Satellite Trunk.
A circuit or path connecting a satellite to its central or proprietary supervising station.

SBCCI.
Southern Building Code Congress International, Inc., 900 Montclair Rd, Birmingham, AL 35213.

Scanner.
Equipment located at the telephone company wire center that monitors each local leg and relays status changes to the alarm center. Processors and associated equipment might also be included.

Secondary Power.
See Standby Battery.

Secondary Trunk Facility.
That part of a transmission channel connecting two or more, but fewer than all, leg facilities to a primary trunk facility.

Separate Sleeping Area.
An area of the family living unit in which the bedrooms (or sleeping rooms) are located. Bedrooms (or sleeping rooms) separated by other use areas, such as kitchens or living rooms (but not bathrooms) are considered as separate sleeping areas.

Shall.
Indicates a mandatory requirement.

Shunt Non-Interfering (SNI) Coded System.
A coded system in which a fire alarm station, once actuated, transmits not less than three rounds of coded alarm signals without interference from any station electrically more distant from the control unit.

Shunt Non-Interfering Successive (SNIS) Coded System.
A shunt non-interfering system in which a fire alarm station, when interrupted by a station electrically closer to the control panel, will complete the sending of the interrupted portion of its code when the station with higher priority completes transmission.

Shapes of Ceilings.
The shapes of ceilings are classified as follows:
  • Sloping Ceiling.

A ceiling having a slope of more than 1 1/2″/ft (41.7 mm/m). Sloping ceilings are further classified as follows:
  • Sloping-Peaked Type. A ceiling in which the ceiling slopes in two directions from the highest point. Curved or domed ceilings can be considered peaked with the slope figures as the slope of the chord from highest to lowest point.
  • Sloping-Shed Type. A ceiling in which the high point is at one side with the slope extending toward the opposite side.
  • Smooth Ceiling. A ceiling surface uninterrupted by continuous projections, such as solid joists, beams, or ducts, extending more than 4 in. (100 mm) below the ceiling surface. Open truss constructions are not considered to impede the flow of fire products unless the upper member in continuous contact with the ceiling projects below the ceiling more than 4 in. (100 mm).Should. Indicates a recommendation or that which is advised but not required.

Shunt Auxiliary Alarm System.
See Auxiliary Fire Alarm System. Signal. A status indication communicated by electrical or other means.

Signaling Line Circuit (SLC).
A circuit or path between any combination of circuit interfaces, control units, or transmitters over which multiple system input signals or output signals, or both, are carried.

Signaling Line Circuit Interface (SLCI).
A system component that connects a signaling line circuit to any combination of initiating devices, initiating device circuits, notification appliances, notification appliance circuits, system control outputs, and other signaling line circuits.

Signaling Line Circuit Loop.
The physical wire loop along which addressable input and/or output devices are connected.

Signal Silence.
A function which causes participating fire alarm activated notification appliances or other outputs to deactivate without otherwise affecting the overall state of the system.

Signal Transmission Sequence
– A DACT that obtains dial tone, dials the number(s) of the DACR, obtains verification that the DACR is ready to receive signals, transmits the signals, and receives acknowledgment that the DACR has accepted that signal before disconnecting (going on-hook).

Silence Inhibit
– The ability of a fire alarm control unit to prevent the signal silence button from operating until after a prescribed amount of time.

Single Station Alarm
– A detector comprising an assembly incorporating a sensor, control components, and an alarm notification appliance in one unit operated from a power source either located in the unit or obtained at the point of installation.

Single Station Alarm Device
– An assembly incorporating the detector, the control equipment, and the alarm-sounding device in one unit operated from a power supply either in the unit or obtained at the point of installation.

Site-Specific Software
– Software that defines the specific operation and configuration of a particular system Typically, it defines the type and quantity of hardware modules, customized labels, and specific operating features of a system.

Smoke Alarm
– A single or multiple station alarm responsive to smoke.

Smoke Barrier
– A continuous membrane, either vertical or horizontal, such as a wall, floor, or ceiling assembly, that is designed and constructed to restrict the movement of smoke. A smoke barrier might or might not have a fire resistance rating. Such barriers might have protected openings.

Smoke Compartment
– A smoke compartment is a space within a building enclosed by smoke barriers on all sides, including the top and bottom. In the provision of smoke compartments utilizing the outside walls or the roof of a building, it is not intended that outside walls or roofs or any openings therein are capable of resisting the passage of smoke.

Smoke Detector
– A device that detects visible or invisible particles of combustion.

Solenoid
– A coil of wire so arranged around a core of air, iron, or other material to transform electrical energy to mechanical energy.

Solid Joist Construction
– Refers to ceilings having solid structural or solid nonstructural members projecting down from the ceiling surface for a distance of more than 4 in. (100 mm) and spaced at intervals 3 ft (0.9 m) or less, center to center.

Spacing
– A horizontally measured dimension related to the allowable coverage of fire detectors.

Spark
– A moving ember. The overwhelming majority of applications involving the detection of Class A and Class D combustibles with radiant energy-sensing detectors involve the transport of particulate solid materials through pneumatic conveyor ducts or mechanical conveyors. It is common in the industries that include such hazards to refer to a moving piece of burning material as a “spark” and to systems for the detection of such fires as “spark detection systems”.

Spark/Ember Detector
– A radiant energy fire detector that is designed to detect sparks or embers, or both. These devices are normally intended to operate in dark environments and in the infrared part of the spectrum.

Spark/Ember Detector Sensitivity
– The number of watts (or fraction of a watt) of radiant power from a point source radiator, applied as a unit step signal at the wavelength of maximum detector sensitivity, necessary to produce an alarm signal from the detector within the specified response time.

Spot-Type Detector
– A device in which a detecting element is concentrated at a particular location. Typical examples are bimetallic detectors, fusible alloy detectors, certain pneumatic rate-of-rise detectors, certain smoke detectors, and thermoelectric detectors.

Standard Audible Emergency Evacuation Signal
– A distinctive three-pulse temporal pattern emergency evacuation signal required by NFPA 72 for all new systems installed after July 1, 1996. For a detailed description of this signal see American National Standards (ANSI) S3.41, Audible Emergency Evacuation Signal.

Standby Battery
– A battery referred to as the secondary power supply, which is kept charged by the fire alarm control unit or by a separate battery charger. When primary (AC) power fails, the battery supplies power for a limited time. The time required for a standby battery to operate the fire alarm system is defined by NFPA 72-1996 1-5.2.6.

Storage Occupancy
– Storage occupancies include all buildings or structures utilized primarily for the storage or sheltering of goods, merchandise, products, vehicles, or animals. Storage occupancies include barns; hangars (for storage only); bulk oil storage; parking structures; cold storage; stables; freight terminals; truck and marine terminals; grain elevators; and warehouses.

Story
– The portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above.

Stratification
– The phenomenon where the upward movement of smoke and gases ceases due to the loss of buoyancy.

Subscriber
– The recipient of contractual supervising station signal service(s). In case of multiple, noncontiguous properties having single ownership, the term refers to each protected premises or its local management.

Subsidiary Station
– A subsidiary station is a normally unattended location that is remote from the supervising station and linked by a communications channel(s) to the supervising station. Interconnection of signals on one or more transmission channels from protected premises with a communications channel(s) to the supervising station is performed at this location.

Supervising Station
– A facility that receives signals and at which personnel are in attendance at all times to respond to these signals.

Supervision
– The term supervised refers to monitoring of the circuit, switch, or device in such a manner that a trouble signal is received when a fault that would prevent normal operation of the system occurs.

Supervisory Service
– The service required to monitor performance of guard tours and the operative condition of fixed suppression systems or other systems for the protection of life and property.

Supervisory Signal
– A signal indicating the need of action in connection with the supervision of guard tours, the fire suppression systems or equipment, or the maintenance features of related systems.

Supervisory Signal-Initiating Device
– An initiating device such as a valve supervisory switch, water level indicator, or low-air pressure switch on a dry-pipe sprinkler system whose change of state signals an off-normal condition and its restoration to normal of a fire protection or life safety system, or a need for action in connection with guard tours, fire suppression systems or equipment, or maintenance features of related systems.

Supplementary
– As used in NFPA 72, National Fire Alarm Code, supplementary refers to equipment or operations not required by NFPA 72, National Fire Alarm Code, and designated as such by the authority having jurisdiction.

Switched Telephone Network
– An assembly of communications facilities and central office equipment operated jointly by authorized service providers that provides the general public with the ability to establish transmission channels via discrete dialing.

System Unit
– The active subassemblies at the central station utilized for signal receiving, processing, display, or recording of status change signals; a failure of one of these subassemblies causes the loss of a number of alarm signals by that unit.
 
T
Time Control Module (TCM) – Used with a fire alarm control unit to provide releasing service and pre-signal evacuation.

Tamper Supervisory Device
– A device used to monitor the position of a water valve, which isolates a waterflow or water pressure switch.

Thermal Lag
– See Rate Compensation Detector.

Transmission Channel
– A circuit or path connecting transmitters to supervising station or subsidiary stations on which signals are carried.

Transmitter
– A system component that provides an interface between signaling line circuits, initiating device circuits, or control units and the transmission channel.

Transponder
– A multiplex alarm transmission system functional assembly located at the protected premises.

Trouble Signal
– A signal initiated by the fire alarm system or device indicative of a fault in a monitored circuit or component.

Trunk Facility
– That part of a signaling line circuit connecting two or more leg facilities to the central station supervising station or satellite station.

Trunk Primary Facility
– That part of a transmission channel connecting all leg facilities to a central or proprietary supervising station or subsidiary station.

Trunk Secondary Facility
– That part of a transmission channel connecting tow or more, but less than all, leg facilities to a primary trunk facility.

Two-Way Fire Department Communications System
– An electrically supervised telephone system providing private voice communication capability between the command center or central control panel and designated remote locations.
 
U
UL – Underwriters Laboratories, Inc., 333 Pfingsten Road, Northbrook, IL 60062.

Unwanted Alarm
– See Nuisance Alarm.

USDOC
– U.S. Department of Commerce, National Bureau of Standards, Washington, D.C. 20234.
 
V
Visible Signal – A visible signal is the response to the operation of an initiating device by one or more direct or indirect visible notification appliances. For a direct visible signal, the sole means of notifications by direct viewing of the light source. For an indirect visible signal, the sole mans of notification is by illumination of the area surrounding the visible signaling appliance.

Voice Paging Protective Signaling System
– A manual or automatic supervised paging system used to transmit a voice message, which may include information, instructions, or directions following a fire alarm, on a selective or all-call basis.

VoIP.
– Voice over Internet Protocol (VoIP) systems are the new low cost telephone services that send calls over the Internet instead of traditional phone lines or any other IP-based network.
 
W-X-Y-Z
Walk Test – A feature that allows a single person to test a fire alarm system.

Waterflow Detector
– A device which detects the flow of water in a deluge system.

Waterflow Switch
– An assembly approved for the service and so constructed and installed that any flow of water from a sprinkler system equal to or greater than that from a single automatic sprinkler of the smallest orifice size installed on the system will result in activation of this switch and subsequently indicate an alarm condition.

WATS (Wide Area Telephone Service)
– Telephone Company service allowing reduced costs for certain telephone call arrangement; it can be in-WATS or 800-number service where calls can be placed from anywhere in the continental U.S. to the called party at no cost to the calling party, or out-WATS, a service whereby, for a flat-rate charge, dependant on the total duration of all such calls, a subscriber can make an unlimited number of calls within a prescribed area from a particular telephone terminal without the registration of individual call charges.

Wavelength
– The distance between the peaks of a sinusoidal wave. All radiant energy can be described as a wave having a wavelength. Wavelength serves as the unit of measure for distinguishing between different parts of the spectrum. Wavelengths are measured in microns (uM), or Angstroms (Å). The concept of wavelength is extremely important in selecting the proper detector for a particular application. There is a precise interrelation between the wavelength of light being emitted from a flame and the combustion chemistry producing the flame. Specific subatomic, atomic, and molecular events yield radiant energy of specific wavelengths. For example, ultraviolet photons are emitted as the result of the complete loss of electrons or very large changes in electron energy levels. During combustion, molecules are violently torn apart by the chemical reactivity of oxygen, and electrons are released in the process, recombining at drastically lower energy levels, thus giving rise to ultraviolet rations. Visible radiation is generally the result of smaller changes in electron energy levels within the molecules of fuel, flame intermediates, and products of combustion. Infrared radiation comes from the vibration of molecules or parts of molecules when they are in the superheated state associated with combustion. Each chemical compound exhibits a group of wavelengths at which it is resonant. These wavelengths constitute the chemical’s infrared spectrum, which is usually unique to that chemical. This interrelationship between wavelength and combustion chemistry affects the relative performance of various types of detectors with respect to various fires.

Wet Location
– See Location, Wet.

Wireless Control Panel
– A component that transmits/receives and processes wireless signals.

Wireless Initiating Device
– Any initiating device that communicates with an associated control/receiving equipment by some kind of wireless transmission path.

Wireless Protection System
– A system or a part of a system that can transmit and receive signals without the aid of wire. It may consist of any of the following components:

Wireless Repeater
– A component used to relay signals between wireless receivers or wireless control panels, or both.

Wireless Radio Linker
– A device that receives, verifies, and retransmits coded low power radio frequency alarm and supervisory signals generated by wireless smoke detectors and other wireless initiating devices.

Wireless Smoke Detector
– A smoke detector which communicates with associated control / receiving equipment using radio transmission.

Zone
– An alarm system with many input devices is often separated into a number of areas called ZONES. Each zone has an indicator light on the keypad which present status of the zone. When all zones are secured alarm system is ready to be armed. In case of alarm ,Control Panel report to the monitoring station condition of each zone tripped .