An alarm (French: À l'arme - "To the arms") gives an audible or visual warning of a problem or condition. Alarm may refer to: Alarm, a device that gives an audible or visual warning of a problem or condition ALARM, (Air Launched Anti-Radiation Missile) a British anti-radiation missile designed primarily to destroy enemy radars The Alarm, a Welsh alternative rock band, who were most popular in the 1980s... Look up warning in Wiktionary, the free dictionary. ...

Alarms include:

• burglar alarms, designed to warn of burglaries; this is often a silent alarm: the police or guards are warned without indication to the burglar, which increases the chances of catching him or her.
• alarm clocks can produce an alarm at a given time
• Distributed control manufacturing systems or DCSs, found in nuclear power plants, refineries and chemical facilities also generate alarms to direct the operator's attention to an important event that he or she needs to address.
• Alarms in an Operation and Maintenance (O&M) Monitoring system, which informs the bad working state of (a particular part of the) system under monitoring.
• safety alarms, which go off if a dangerous condition occurs. Common public safety alarms include:
  • tornado sirens
  • fire alarms
  • car alarms
  • Community Alarm or Autodialer alarm (medical alarms)
  • air raid sirens
  • tocsins — a historical method of raising an alarm

Alarms have the capability of causing a fight-or-flight response in humans; a person under this mindset will panic and either flee the perceived danger or attempt to eliminate it, often ignoring rational thought in either case. We can characterise a person in such a state as "alarmed". Burglar (or intrusion), fire and safety alarms are found in electronic form today. ... Burglary is a crime related to United States burglary is a felony and involves trespassing, or entering a building with intent to commit any crime, not necessarily a felony or theft. ... A basic digital clock radio with analog tuning A wind-up, spring-driven alarm clock An alarm clock is a clock that is designed to make an alert sound at a specific date and/or time. ... A distributed control system (DCS) refers to a control system usually of a manufacturing system, process or any kind of dynamic system, in which the controller elements are not central in location (like the brain) but are distributed throughout the system with each component sub-system controlled by one or... Core of a small nuclear reactor used for research. ... A refinery is composed of a group of chemical engineering unit processes and unit operations used for refining certain materials or converting raw material into products of value. ... Thunderbolt 1000/1000T Civil Defense siren. ... A Wheelock MT-24-LSM fire alarm horn and strobe. ... A car alarm is an electronic device installed in a vehicle in an attempt to discourage theft. ... An autodialer alarm is an electrical device that usually has a push button transmitter which an individual may use to summon assistance to their location. ... An autodialer alarm is an electrical device that usually has a push button transmitter which an individual may use to summon assistance to their location. ... Thunderbolt 1000/1000T Civil Defense siren. ... A tocsin consists of a signal of alarm given by the ringing of a bell, and hence any warning or danger signal. ... The fight-or-flight response, also called hyperarousal or the acute stress response, was first described by Walter Cannon in 1915[1][2]. His theory states that animals react to threats with a general discharge of the sympathetic nervous system, priming the animal for fighting or fleeing. ... This article is about modern humans. ...

With any kind of alarm, the need exists to balance between on the one hand the danger of false alarms (called "false positives") — the signal going off in the absence of a problem — and on the other hand failing to signal an actual problem (called a "false negative"). False alarms can waste resources expensively and can even be dangerous. For example, false alarms of a fire can waste firefighter manpower, making them unavailable for a real fire, and risk injury to firefighters and others as the fire engines race to the alleged fire's location. In addition, false alarms may acclimatise people to ignore alarm signals, and thus possibly to ignore an actual emergency: Aesop's fable of The Boy Who Cried Wolf exemplifies this problem. This article is about the profession. ... Nofootnotes|date=February 2008}} Aesop, as conceived by Diego Velázquez Aesop, as depicted in the Nuremberg Chronicle by Hartmann Schedel in 1493. ... For other uses, see Fable (disambiguation). ... The Boy Who Cried Wolf, illustrated by Milo Winter in a 1919 Aesop anthology For other uses, see Cry Wolf (disambiguation). ...

Etymology

"Alarm" came from Old French 'à l'arme' = "to the weapon", telling armed men to pick up their weapons and get ready for action (because an enemy may have suddenly appeared).

See also

• Alarm management
• Burglary
• Burglar alarm
• Clock
• False alarm
• Fire alarm notification appliance
• Physical Security
• Smoke detector