Smoke detectors: a complete guide

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Installing fire alarms in homes, businesses, and industries is now standard procedure to ensure the safety of those who live, work, and play there. Based on these options, the sort of smoke detector to use can be determined. For example, smoke alarms in a typical home would flash or sound an alert if they detect smoke. However, in commercial buildings, smoke alarms will send a signal to the fire alarm system, which will contact the appropriate emergency services. The number of fires and false alarms investigated by the British fire and rescue department decreased by 5% between 2009-2010 to 2010-2011. Additionally, research has indicated that the percentage of homes with smoke alarms increased from 8 percent in 1988 to 86 percent in 2008, which lead to decrease in fire-rescue cases. Check out smoke detectors home depot for purchasing good quality detectors. A disposable battery powers the disc-shaped design of the conventional home smoke detector. Photoelectric and ionizing smoke detectors are the two main varieties on the market. Smoke detectors that use photoelectric technology The photoelectric smoke detector uses a light beam and electrical photocells (photodiodes) to track smoke particles. Light from a smoke detector's incandescent bulb or LED light will reflect off the photocells and into the detector itself. Because the photocells are positioned at a right angle to the light beam, the photocells are less likely to be influenced by light entering the chamber. This occurs when smoke particles are introduced into an optical chamber, which causes the light beam to be obstructed by these particles (i.e., light reflects off of the smoke particles). When the electrical charge in the detector reaches a certain level, an alarm is triggered, and the user is notified. Related Articles Infrared and Ultraviolet (UV/IR) detectors for fire detection. New Photoelectric Smoke and Duct Smoke Detectors by Nortek Security & Control are now available Detector Sensor 2GIG As a rule of thumb, photoelectric smoke detectors have been put in gymnasiums and auditoriums. Advantages Suitable for detecting thick smog It is less likely to be falsely triggered by cooking odors or steam from a shower. Make them safer to use because they don't contain radioactive materials. Disadvantages Regular maintenance is required because of its sensitivity to dust particles and insect infestations. The cost of upkeep is high. To run properly, it has to be updated (they are typically wired to a 110-volt power source) It is possible to obstruct the light beam of a conventional photoelectric smoke detector in two ways: The light-blocking technique. Light beams are obscured by dense smoke, whereas less dense smoke particles can move about more freely, thus impacting the alarm system. Some smoke particle coverage measurements use a mirror to orient the beam of light. The principle of light scattering The light scattering principle is based on the idea that smoke particles entering the sensing chamber strike the light beam and scatter the light onto photoelectric particles. The Ionizing Smoke Detector Ionizing smoke detectors use radioisotopes, such as americium-241 that ionize smoke particles in the atmosphere. Radioactive isotope Americium-241 functions by emitting alpha particles, which ionize air particles in the sensor chamber and allow electricity to flow through them. To generate an electric charge in the air, an electrochemical reaction takes place in the collecting chamber while the alpha particles are being emitted into the atmosphere. These particles enter the collecting chamber and clog up the ionization chamber, making it less likely for them to provide an electrical charge to smoke detectors. A circuit detects a decrease in electrical flow and subsequently activates an alert system. When compared to a photoelectric detector, this sort of smoke detector is great for detecting the invisible particles produced by flames and thus will function faster and be more sensitive. The ionizing smoke detector uses alpha particles because they have a large potential for ionization. As a result, the alpha particles used in these smoke detectors have a low penetrative potential and will not penetrate through the plastic. Only 37KBq or 1Ci of radioactive Americium-241 is needed in an ionizing smoke detector to detect smoke particles without damaging the device's exterior. Hence there are no regulatory concerns raised by this amount. In order to satisfy regulatory standards for radiation safety, ionizing smoke detectors must undergo a radiation safety analysis before being on the market. Photoelectric smoke detectors cost more than ionizing smoke detectors, although they are less frequent. Advantages More cost-effective than photoelectric smoke detectors. Fires that burn quickly and produce little visible smoke require ionizing smoke alarms, which outperform photoelectric smoke alarms in this regard. Disadvantages False alarms may occur as a result of cooking, which is extremely sensitive. Detecting smoke particles from smoldering fires is more difficult with these sensors since they are several minutes slower than photoelectric sensors. A worry is the use of radioactive substances.

Installing fire alarms in homes, businesses, and industries is now standard procedure to ensure the safety of those who live, work, and play there. Based on these options, the sort of smoke detector to use can be determined.

For example, smoke alarms in a typical home would flash or sound an alert if they detect smoke. However, in commercial buildings, smoke alarms will send a signal to the fire alarm system, which will contact the appropriate emergency services.

The number of fires and false alarms investigated by the British fire and rescue department decreased by 5% between 2009-2010 to 2010-2011. Additionally, research has indicated that the percentage of homes with smoke alarms increased from 8 percent in 1988 to 86 percent in 2008, which lead to decrease in fire-rescue cases. Check out smoke detectors home depot for purchasing good quality detectors.

A disposable battery powers the disc-shaped design of the conventional home smoke detector. Photoelectric and ionizing smoke detectors are the two main varieties on the market.

Smoke detectors that use photoelectric technology

The photoelectric smoke detector uses a light beam and electrical photocells (photodiodes) to track smoke particles. Light from a smoke detector’s incandescent bulb or LED light will reflect off the photocells and into the detector itself. Because the photocells are positioned at a right angle to the light beam, the photocells are less likely to be influenced by light entering the chamber.

This occurs when smoke particles are introduced into an optical chamber, which causes the light beam to be obstructed by these particles (i.e., light reflects off of the smoke particles). When the electrical charge in the detector reaches a certain level, an alarm is triggered, and the user is notified.

Related Articles

Infrared and Ultraviolet (UV/IR) detectors for fire detection. New Photoelectric Smoke and Duct Smoke Detectors by Nortek Security & Control are now available Detector Sensor 2GIG

As a rule of thumb, photoelectric smoke detectors have been put in gymnasiums and auditoriums.

Advantages

Suitable for detecting thick smog

It is less likely to be falsely triggered by cooking odors or steam from a shower.

Make them safer to use because they don’t contain radioactive materials.

Disadvantages

Regular maintenance is required because of its sensitivity to dust particles and insect infestations.

The cost of upkeep is high

To run properly, it has to be updated (they are typically wired to a 110-volt power source)

It is possible to obstruct the light beam of a conventional photoelectric smoke detector in two ways:

The light-blocking technique

Light beams are obscured by dense smoke, whereas less dense smoke particles can move about more freely, thus impacting the alarm system. Some smoke particle coverage measurements use a mirror to orient the beam of light.

The principle of light scattering

The light scattering principle is based on the idea that smoke particles entering the sensing chamber strike the light beam and scatter the light onto photoelectric particles.

The Ionizing Smoke Detector

Ionizing smoke detectors use radioisotopes, such as americium-241 that ionize smoke particles in the atmosphere. Radioactive isotope Americium-241 functions by emitting alpha particles, which ionize air particles in the sensor chamber and allow electricity to flow through them.

To generate an electric charge in the air, an electrochemical reaction takes place in the collecting chamber while the alpha particles are being emitted into the atmosphere. These particles enter the collecting chamber and clog up the ionization chamber, making it less likely for them to provide an electrical charge to smoke detectors.

A circuit detects a decrease in electrical flow and subsequently activates an alert system. When compared to a photoelectric detector, this sort of smoke detector is great for detecting the invisible particles produced by flames and thus will function faster and be more sensitive.

The ionizing smoke detector uses alpha particles because they have a large potential for ionization. As a result, the alpha particles used in these smoke detectors have a low penetrative potential and will not penetrate through the plastic.

Only 37KBq or 1Ci of radioactive Americium-241 is needed in an ionizing smoke detector to detect smoke particles without damaging the device’s exterior. Hence there are no regulatory concerns raised by this amount.

In order to satisfy regulatory standards for radiation safety, ionizing smoke detectors must undergo a radiation safety analysis before being on the market. Photoelectric smoke detectors cost more than ionizing smoke detectors, although they are less frequent.

Advantages

  • More cost-effective than photoelectric smoke detectors.
  • Fires that burn quickly and produce little visible smoke require ionizing smoke alarms, which outperform photoelectric smoke alarms in this regard.

Disadvantages

  • False alarms may occur as a result of cooking, which is extremely sensitive.
  • Detecting smoke particles from smoldering fires is more difficult with these sensors since they are several minutes slower than photoelectric sensors.
  • A worry is the use of radioactive substances.