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May 20, 2024

What is the Meaning of Alarm Device?

An alarm device is a mechanism that gives an audible or visual signal to alert someone of a hazard or the need for immediate action. Early alarm devices were bells, drums or other musical instruments that attracted the attention of the people around them, and more recently these have been replaced by alarm sirens which are designed to draw even more attention to the occurrence, and increase the likelihood of a quick response from police, fire or other emergency services.

An intrusion alarm system is a combination of sensors and devices that are intended to detect unauthorized entrants into a property. The sensors may be located at the perimeter of the building, or within a specific area to be protected, and will typically use different methods to detect a hazard or intruder including door and window contact sensors, motion sensor alarms, and smoke detectors. An alarm panel is then able to read the signals from these devices and send them to a central monitoring station or other designated location, who in turn will notify appropriate emergency services.

Some alarm systems incorporate dual signaling, which combines a radio or cellular path with a traditional telephone line in order to ensure that an alarm will still be able to reach the monitor if the phone circuit is compromised. Encoders can also be installed that will show which particular sensor was triggered, and in some cases the monitor can display a map showing the physical location of the sensor - all of which can make the response from an alarm system more effective and efficient.

Audible alarms or horns are often included in the system as a way to provide a loud audible signal that will scare off a potential intruder, and may also include flashing lights as well. The visual nature of these can be a deterrent that is particularly useful in commercial settings, where the requirement to comply with OSHA regulations on employee alarms means that an audible alarm must be loud enough to be heard and seen over ambient noise and lighting levels.

Most alarm systems will also be connected to a backup communication path which can be used in the event that the primary PSTN connection becomes compromised, such as a digital cellular solution. This allows the alarm system to continue sending signals to a monitoring company without a loss of service, and can be configured to send the signal either via a synthesized voice or increasingly using an encoded message string that the central station can decode.

Many systems will include keypads which allow a user to arm or dis-arm the alarm, and to access the settings for individual sensors in a particular zone. Some will also have the ability to remotely program a control panel, which can be especially helpful in situations where there are multiple users of a system and each may require unique configurations for their sensors and zones. Other sensors will include a bypass capability which allows the activation of a single sensor to be temporally ignored or disconnected from the alarm system, so that it cannot trigger a false alarm.