How alarm systems work?

Answer 1

There are a lot of fire alarm systems depending what kind of an alarm system you want.Fire alarm system with (smoke detectors,heat detectors,flame detectors almost the same with heat detectors,ionized smoke detectors and duct detectors) depending on the system of your needs.For you to understand it I will explain 2 of it.Smoke detectors have smoke sensors in side if the smoke is too much the alarm system starts to work,that means alarm works.How the alarm works the smoke detection system analysis the air which goes through it , if the sensor senses any increase of CO or CO2 then it starts the alarm. Flame or heat detector has a contact which is made of 2 different materials which has different specific heat, İf any heat reaches to this contact according t the different specific heated material contact bends towards the more specific heated material( you can do it with copper and iron at home if you fix them with a nonmetallic material and heat them even with a lighter you will see it with your eyes) than the alarm starts because the contact touches a metallic material to give the energy to the horn or bell.( for more specific information try Notifier or Honeywell

Answer 2

Fire alarms generally sense things that are related to fire and activate a warning system, either locally or remotely or both.

There are three major types of fire alarm sensors, all of which operate slightly differently:

Thermal fire alarms - used primarily by large commercial or industrial facilities, thermal fire alarms go off when an internal thermostat reaches a certain level. This makes them arguably the least safe type of fire alarm, because they only detect a fire once it's gotten pretty strong. Thermal fire alarms are most useful in areas where low levels of smoke, dust or heat (factories, warehouses, etc) is normally present and can trigger a false alarm.

Other thermal-type sensors include: tubing-type (in which external heat activates a thermistor), wire-type (in which insulation melts to allow the wires to touch), and various rate-of-rise detectors (calibrated to alarm when heat rapidly increases).

Ionization fire alarms - these fire alarms use harmless radioactivity to ionize the air within the plenum in the detector. This allows a small electric current to pass through. When smoke particles enter the detector, it disrupts the flow of the electric current. If the flow drops too much, it triggers an alarm. Ionization fire alarms are best at detecting smoky fires but are typically not effective against smoke from smoldering fires.

According to IFSTA, ionization sensors detect flaming fires more quickly than do photoelectric sensors.

Photoelectric fire alarms - photoelectric fire alarms use a beam of light and a nearby, light sensitive photocell. When smoke enters the detection chamber, it scatters the beam, with some light hitting the cell. When the cell detects the light, it emits an alarm.

According to IFSTA, photoelectric sensors detect smoldering fires more quickly than ordinary ionization-type sensors.

Other types of fire alarm sensors include:

Flame Detectors;

Fire-Gas Detectors;

Combinations of the above;

Water-flow sensors (on automatic sprinkler systems);

Fire extinguisher sensors (on some fixed installations);

Tamper switches (to monitor water or air pressure or valve settings, etc).

There are also numerous types of Manual Pull Stations for activating a fire alarm system, whether with one motion (pull lever) or two motions (lift cover, pull leer). Some exit-door "panic hardware" may also activate the fire alarm.

Fire alarms sense smoke, heat or other indications of fire (sprinkler flow, manual pull stations) and activate horns, strobe lights or bells, or automatic voice instructions, to warn people of the fire. It may also signal a monitoring station where information can be give to dispatch an appropriate fire brigade.

Answer 3

Commonly, modern type bells have motors inside of them which when they are powered, it spins round continuously a hammer which hits the outside part of the bell (Dong) very fast and that's what creates the bell noise.

Older types use elctro magnets. When powered, the hammer is ver quickly pulled back and forth by the electromagnet.

Answer 4

Fire alarms use various types of sensors to detect fires automatically, generally by sensing smoke, heat, rate of rise of the temperature, detecting flames, or other physical or chemical indications of fire. Some fire alarms also monitor other systems designed to put out fires, such as sprinklers or fire extinguishers, using the fact that there must be a fire if those systems have been activated.

Fire alarms also use manual pull stations to "know there's a fire", meaning that the alarm knows because someone manually signaled the fire.

Answer 5

The fire alarm's main objective is to 'alarm' people when there is a fire in a building (most found in public areas like schools, rooms with high fire rates, and skyscrapers.) The ones in big buildings connect to the water supply, so the water is able to stop the fire.

Answer 6

Alarm systems work by monitoring protective loops in a premise or asset, when a loop is broken or disturbed and alarm is issued. This alarm can be audible or silent and transmitted by radio signal, satellite signal, telephone line to an alarm monitoring center where the received signal is acted on and the appropriate action or authorities are notified.

Answer 7

There are 2 types of smoke detectors: ionization detectors and photoelectric detectors. Although they use different mechanisms both essential set off an alarm when smoke obscures the line of sight between 2 objects within the detector.

Answer 8

It depends on the alarm system, when a home system connected to say, a window, is activated and on. If the windows is opened and the circuit broken the alarm will sound.