Losses will be reduced if each developing fire were detected. Fire detection devices are:
- Human observer
- Automatic sprinklers
- Smoke, flame or heat detectors
The two main tasks of fire detection are:
- To give early warning to enable building occupants to escape
- To start extinguishing procedures
Buildings should be equipped with fire alarm signal systems that clearly:
- Communicate to all where the fire is located and
- Summon appropriate fire fighting units. Whenever an alarm is sounded all employees must know what the sound means.
The next important factor in effectively detecting the threat of fire is to look at
the various types of smoke detectors on the market. Smoke detectors are
abundant and are found in almost every hardware and grocery store in town. As
with anything that costs money, not all smoke detectors are created equal.
From the basic technologies involved to the testing procedures, it is important
to know what you are buying. U.L.C. (Underwriters Laboratories of Canada)
does test and rates fire devices, however you should still examine the
technologies as well as how their limitations may apply to the area in which
they are installed.
There are two basic types of smoke detectors available today. Yes, at the end of
the day, both detect fires but the differences lie in reliability and detection
technology.
I – Ionization detectors are the most common and often least expensive
detectors available. This detectors' smoke chamber contains a radioactive
source that emits radiation, resulting in a weak flow of electric current. When
particles such as those produced by fire enter the smoke chamber, they reduce
the current and trigger the alarm. This type of detector is generally most
effective in detecting the “products of combustion” produced during the
incipient stage of a fire.
Although early detection is always desirable, there are several inherent flaws
with this technology. For example, some ionization detectors are not as
effective in detecting the smoke produced during the smoldering stage. Another
downfall is their general susceptibility to false alarms that have a tendency to
become more than a minor nuisance, once the fire department is dispatched.
II – Photoelectric detectors, although not effective in detecting the invisible
gases created during the incipient stage, are generally more stable and reliable
when it comes to false alarm immunity. Further to that, good quality
photoelectric detectors are far superior at detecting visible smoke that may not
contain the invisible gases required to set off an ionization detector.